Microbiology And Parasitology For Nurses Lec And Lab A Self Regulated Lab Module

SCHOOL OF NURSING

NMCPAR1 NMCPAL1

MICROBIOLOGY AND PARASITOLOGY FOR NURSES LEC AND LAB

Prepared by: Vivien Rios, MAN, RN, RM Elton John Delos Santos MAN,MaEd,RN Genesis N. Dela Cruz, MAN, RN Richard S. Rosalin,RN Nancy Fucasan RN, MAN

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TABLE OF CONTENTS

INTRODUCTION OF THE MODULE Course Code and Title Course Description Requirements of the Course Learning Outcomes Study Schedule Letter of Undertaking

PAGES 4 4 4 5 5 8

UNIT I. INTRODUCTION A. Foundations

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B. Cell Structure & Host Pathogen Relationship

18

C. Check for Facts and Understanding

36

D. Laboratory

43

UNIT II. MICROBIAL MECHANISMS OF PATHOGENICITY A. Requirements for Infection

48

B. Transmission of infection, the compromised Host and Epidemiology

50

C. Principles of Disease

52

D. Emerging and Re-emerging infectious diseases

53

E. Check for Facts and Understanding

54

F. Laboratory

57

UNIT III. CHARACTERISTICS OF DISEASE- CAUSING MICROORGANISM A. Bacteria

66

B. Viruses

75

C. Parasitic and Fungal infections

80

D. Check for Facts and Understanding

83

E. Laboratory

86

UNIT IV. HOST DEFENSE MECHANISM A. Definition of terms, concepts B. Innate Immune Response C. Types of Acquired/ Adaptive immunity

90 91

D. Failures of the immune response

96

E. Applications of immunology

99

F. Check for Facts and Understanding

104

G. Laboratory

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UNIT V. MICROBIAL INFECTIONS A. Infections of Respiratory system

111

B. Infections of the Digestive system

152

C. Check for Facts and Understanding

218

D. Infections of the Genitourinary system

219

E. Check for Facts and Understanding

246

F. Infections of the Central Nervous System

250

G. Check for Facts and Understanding

273

H. Infections of the Blood

277

I.

297

Check for Facts and Understanding

J. Infections of the Skin and Eyes

301

K. Check for Facts and Understanding

341

L. Laboratory

345

UNIT VI. CONTROL AND TREATMENT A. Control of Microbial with disinfection and antiseptics

349

B. Antibiotics

389

C. Antiviral agents

397

D. Laboratory Activity 7

404

E. Laboratory Activity 8

411

UNIT VII. BEST AND IMPORTANT ISSUES IN MICROBIOLOGY A. Biotechnology

414

B.

Bioterrorism

417

C.

Laboratory Activity 9

492

EVALUATION OF THE COURSE

435

REFERENCES

436

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INTRODUCTION OF THE MODULE Course Code: NMCPAR1, NMCPAL1 Course Title: MICROBIOLOGY AND PARASITOLOGY FOR NURSES Course Description: This course is designed to enable students to acquire understanding of fundamentals of Microbiology and identification of various microorganisms. It also provides opportunities for practicing infection control measures in hospital and community settings. Control provides nursing students with the skills and knowledge to prevent the transmission of organisms in health care settings. The principles of infection control are coupled with the science of parasites and microbial transmission and reproduction. Students gain knowledge of the most important bacterial, fungal, parasitic and viral infections. The use of personal protective equipment and the ability to establish and maintain a sterile field are core skills of nurses. The role of the immune system in defense of the human body is examined and emphasis is placed on the recognition of inflammation.

Requirements of the Course: 1. Recitation. The learners are expected to actively participate during online interactive lectures. They will be asked by the clinical instructor during the interactive lecture and they are expected to share their thoughts and ideas relevant to the subject matter.

2. Quiz. Online quizzes will be administered by the instructor every after each chapter with the use of Google forms. The learners will be given enough time to complete and turn in the quiz before the deadline. Offline quizzes will be provided to all learners who have no connectivity and should submit them on the set deadline by the clinical instructor.

3. Laboratory Experiments/Activities. The learners are expected to complete and turn in laboratory activities per chapter through Google Forms. All other laboratory activities that require the use of laboratory room and equipment should be done in the school as soon as the situation and authorities permit. Refer to the laboratory activities of each chapter for further instructions.

4. Examination. Online examination or unit quizzes should be administered through Google Forms, but it could be done in the school as soon as face-to-face will be allowed.

5. Vlog. The learners are required to record a vlog presenting a disease from the course content with the use of visual aid. The vlog should be at a minimum of 3 minutes and maximum of 5 minutes duration. The learners are given freewill to express their creativity on recording a vlog about the said topic.

6. Attendance. The learner expected to attend an online interactive lecture through google meet or zoom as part of the requirements. Learners who experience weak or no internet connection must notify his/her instructor immediately.

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Learning Competencies: After the course on Microbiology and Parasitology for Nurses, the learners are expected to: 1. apply knowledge of physical, social, natural and health sciences and humanities in the practice of nursing by integrating relevant principles of social, physical, natural and health sciences and humanities in a given health and nursing situation; 2. provide safe, appropriate, and holistic care to individuals, families, population groups, and community utilizing nursing process by instituting appropriate corrective actions to prevent or minimize harm arising from adverse effects; 3. apply guidelines and principles of evidence-based practice in the delivery of care by providing appropriate evidence-based nursing care using a participatory approach based on: variety of theories and standards relevant to health and healing, research, clinical practice, client preferences, client and staff safety, customer care standards, and 4. practice beginning management and leadership skills in using systems approach in their delivery of client care by managing resources (human physical, financial, time) efficiency and effectively.

Study Schedule Grading Period First Grading

Topics

Schedule

UNIT I. INTRODUCTION A. Foundations

Week 1 to 2

B. Cell Structure & Host Pathogen Relationship C. Laboratory D. Check for Facts and Understanding UNIT II. MICROBIAL MECHANISMS PATHOGENICITY A. Requirements for Infection

OF Week 3 to 4

B. Transmission of infection, the compromised Host and Epidemiology C. Principles of Disease D. Emerging and Re-emerging infectious diseases E. Laboratory F. Check for Facts and Understanding

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UNIT III. CHARACTERISTICS OF DISEASE- CAUSING MICROORGANISM A. Bacteria B. Viruses C. Parasitic and Fungal infections

Week 5 to 6

D. Laboratory E. Check for Facts and Understanding Midterms

UNIT IV. HOST DEFENSE MECHANISM A. Definition of terms, concepts B. Innate Immune Response

Week 7 to 8

C. Types of Acquired/ Adaptive immunity D. Immune system Response E. Applications of immunology F. Laboratory G. Check for Facts and Understanding

UNIT V. MICROBIAL INFECTIONS A. Infections of Respiratory system B. Infections of the Digestive system

Week 9 to 10

C. Infections of the Genitourinary system

Week 11

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Finals

1.

2.

3.

4.

5.

Infections of the Central Nervous System Infections of the Blood Infections of the Skin and Eyes Laboratory Check for Facts and Understanding

Week 12 to 13 Week 14 to 15

UNIT VI. CONTROL AND TREATMENT A. Control of Microbial antiseptics B. Antibiotics C. Antiviral agents

with

disinfection

and Week 16 to 17

D. Clinical Significance E. Laboratory F. Check for Facts and Understanding UNIT VII. BEST AND MICROBIOLOGY A. Biotechnology B. Bioterrorism

Clinical Instructors Genesis Dela Cruz, MAN, RN Vivien Rios, MAN, RN, RM Nancy Fucasan RN, MAN Richard S. Rosalin, RN Elton John Delos Santos, MAN, MaEd, RN

IMPORTANT

ISSUES

IN Week 18

genesisdelacruz@e.ubaguio.edu vivienrios@e.ubaguio.edu nancyfucasan@e.ubaguio.edu richardrosalin@e.ubagio.edu elton@e.ubaguio.edu

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Letter of Undertaking

To Whom It May Concern, As a student of the School of Nursing enrolled in the course, Biochemistry for Nursing, assure that I will utilize this module as learning material and will actively participate in each and every learning activities such as but not limited to online learning, blended learning, and self-directed learning. Furthermore, I solemnly swear that I will not commit plagiarism by citing all references I will use in every requirement that I will submit, and will not cheat by practicing honesty and integrity with the best of my abilities in all learning assessments that my professor will administer.

Sincerely, ___________________________________ (Signature of the Student)

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UNIT I. INTRODUCTION Welcome to the fascinating world of microbiology, where you will learn about creatures so small that the vast majority cannot be seen with the naked eye. In this unit, you will discover the effects that these tiny creatures have on our daily lives, the ecosystems, and the environment around us, and why knowledge of them is of great importance to health professionals. You will learn that some of them are our friends, whereas others are our enemies. You are about to embark on an exciting journey. Enjoy the adventure.

Objectives After studying this unit, you should be able to: 1. Correctly define the different terms and concepts pertaining and related to microbiology and parasitology.

2. Identify correctly the different parts and the chemical components of a cell.

3. Give examples of the value of microbiology and parasitology in producing evidence-based knowledge.

4. Present a concept map regarding the different types of microorganisms.

EXPLORE: Do you believe in the theory of Spontaneous Generation? Give one ( 1 ) example to prove your point. Open discussion in Google Meet. ( Importance of Microbiology )

A. FOUNDATIONS: DEFINITION OF TERMS: 1.

MICROBIOLOGY- is the study of microbes. It includes the study of certain nonliving entities as well as certain living organisms. Collectively, these nonliving entities and living organisms are called microbes. Micro means very small-anything so small that it must be viewed with a microscope ( an optical instrument used to observe very small objects ). Therefore, microbiology can be defined as the study of microbes. Microbes are said to be ubiquitous, meaning they are virtually everywhere. The various categories of microbes include viruses, bacteria, archaea, protozoa and certain types of fungi and algae. ( Figure 1 ).

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Figure 1. Acellular and Cellular Microbes Source: https://www.sciencedirect.com/topics/immunology-and-microbiology/microorganism

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Microbes- are tiny living things that are found all around us and are too small to be seen by the naked eye. They live in water, soil, and in the air. The human body is a home to millions of these microbes too, also called microorganisms. Some microbes make us sick, others are important for our health.

Prokaryotes- are unicellular organisms that lack organelles or other internal membrane-bound structures. Therefore, they do not have a nucleus, but instead, generally have a single chromosome: a piece of circular, double stranded DNA, located in an area of the cell called the nucleoid.

Bacteria- a type of biological cell. They constitute a large domain of prokaryotic microorganisms. The first life forms to appear on earth and present in most of its habitat.

Virus- a submicroscopic infectious agent that replicates only inside the living cells of an organism.

Algae- are a diverse group of aquatic organisms that have the ability to conduct photosynthesis. A single or multi-cellular organism that has no roots, stems or leaves and is often found in water.

Eukaryotes- are organisms whose cells have a nucleus within a nuclear envelope.

Fungi- any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds a swell as familiar mushrooms.

Protozoa- term for a group of single-celled eukaryotes, either free living or parasitic, which feed on organic matter such as other microorganisms or organic tissues and debris.

B. BRANCHES OF MICROBIOLOGY 1. Bacteriology- the subdivision of microbiology involves the identification, classification, and characterization of bacterial species.

2. Virology- is the study of viruses- submicroscopic, parasitic particles of genetic material contained in a protein coat and virus like agents.

3. Mycology- concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans as a source for tinder, traditional medicine, food and entheogens as well as their dangers such as toxicity or infection.

4. Protozoology- is the study of protozoa, the “animal-like” protists.

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C. IMPORTANCE OF MICROBIOLOGY Although they are very small, microbes play significant roles in our lives. Listed below are a few of the many reasons to take a microbiology course and to learn about microbes.

1. Microbes that live on and in the human body are referred to as our indigenous microbiota or human microbiome and for the most part, they are of benefit to us. The indigenous microbiota inhibit the growth of pathogens in those areas of the body, where they live by occupying space , depleting the food supply and secreting materials ( waste products, toxins, antibiotics etc. ) that may prevent or reduce the growth of pathogens.

2. Some of the microbes that colonize ( inhabit ) our bodies are known as opportunistic pathogens. Although these microbes usually do not cause any problems, they have the potential to cause infections if they gain access to a part of our anatomy where they do not belong. Other opportunistic pathogens strike when a person becomes run-down, stressed out, or debilitated ( weakened ) as a result of some disease or condition.

3. Microbes are essential for life on this planet as we know it. For example, some microbes produce oxygen by the process known as photosynthesis. Actually, microbes contribute more oxygen to our atmosphere than do plants. Thus, organisms that require oxygen-humans, for example – owe a debt of gratitude to the algae and cyanobacteria ( a group of photosynthetic bacteria ) that produce oxygen.

4. Many microbes are involved in the decomposition of dead organisms and the waste products of living organisms. Collectively, these microbes are referred to as decomposers or saprophytes. Imagine living in a world with no decomposers.

Saprophytes aid in fertilization by returning inorganic nutrients to the soil. They break down dead and dying organic materials ( plants and animals ) into nitrates, phosphates, and other chemicals necessary for the growth of plants. ( Figure 1.2 )

Figure 2: Saprophytes Source: https://widroid.plengdut.com/2016/05/why-we-need-study-about-microbes.html

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5. Some microbes are capable of decomposing industrial wastes ( oil spills, for example ). Thus, we can use microbes-genetically engineered microbes, in some cases- to clean up. The use of microbes in this manner is called bioremediation.

6. Many microbes are involved in elemental cycles, such as carbon, nitrogen, oxygen, sulfur and phosphate cycles. In the nitrogen cycle, certain bacteria convert nitrogen gas in the air to ammonia in the soil. Knowledge of these microbes is important to farmers who practice crop rotation to replenish nutrients in their fields and to gardeners who keep compost pits as a source of natural fertilizer. The study of the relationships between microbes and the environment is called microbial ecology.

Figure 3. Nitrogen Cycle Source: https://byjus.com/biology/nitrogen-cycle/

7. Microbes serve as important links in food chains. Microscopic organisms in the ocean, collectively referred to as plankton, serve as the starting point for many food chains. Tiny marine algae are called phytoplankton, whereas tiny marine animals are called zooplankton.

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Figure 4: Food Chain Source: http://detroitaquarium.weebly.com/food-chains.html

8. Many microbes are essential in various food and beverage industries, whereas others are used to produce certain enzymes and chemicals. The use of living organisms or their derivatives to make or modify useful products or processes is called biotechnology.

Figure 5 Source:https://widroid.plengdut.com/2016/05/why-we-need-study-about-microbes.html

9. Some bacteria and fungi produce antibiotics that are used to treat patients with infectious diseases. By definition, an antibiotic is a substance produced by a microbe that is effective in killing or inhibiting the growth of other microbes. The use of microbes in the antibiotic industry is an example of biotechnology.

10. Microbes are essential in the field of genetic engineering. In genetic engineering, a gene or genes from one organism are inserted into a bacterial or yeast cell.

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Microbiologists have engineered bacteria and yeasts to produce a variety of useful substances, such as insulin, various types of growth hormones, interferons, and materials for use of vaccines.

11. For many years, microbes have been used as cell models. The more scientists learned about the structure and function of microbial cells, the more they learned about cells in general.

12. Finally, we come to diseases. Microbes cause two categories of diseases: infectious diseases and microbial intoxications. An infectious disease results when a pathogen colonizes the body and subsequently causes a disease. A microbial intoxication results when a person ingests a toxin ( poisonous substance ) that has been produced by a microbe.

Figure 6: The two categories of diseases caused by pathogens Source: https://slideplayer.com/slide/12565584/

D. HISTORY OF MICROBIOLOGY Bacteria and protozoa were the first microbes to be observed by humans. It then took about 200 years before a connection was established between microbes and infectious diseases. Among the most significant events in the early history of microbiology were the development of microscopes, bacterial staining procedures, techniques that enabled microorganisms to be cultured ( grown ) in the laboratory, and steps that could be taken to prove that specific microbes were responsible for causing specific infectious diseases.

1. Anton Van Leewenhoek ( 1632-1723 ) Because Anton Van Leewenhoek was the first person to see live bacteria and protozoa, he is sometimes referred to as the “Father of Microbiolgy”, the “Father of Bacteriology”, and the “Father of Protozoology”. As a hobby, he ground tiny glass lenses, which he mounted in small metal frames, thus creating what today are known A Self-regulated Learning Module

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as single-lens microscopes or simple microscopes. He was the first person to see live protozoa. Leewenhoek’s letters finally convinced scientists of the late 17th century of the existence of microbes. He never speculated on their origin, nor did he associate them with the cause of disease.

Once scientists became convinced of the existence of tiny creatures that could not be observed with the naked eye, they began to speculate on their origin. On the Basis of observation, many scientists of that time believed that life could develop spontaneously from inanimate substances, such as decaying corpses, soil and swamp gases. The idea that life can arise spontaneously from nonliving material is called the THEORY OF SPONTANEOUS GENERATION OR ABIOGENESIS. For more than two centuries, from 1650 to 1850, this theory was debated and tested.

Following the work of others, Louis Pasteur and John Tyndall finally disproved the theory of spontaneous generation and proved that life can only arise from preexisting life. This is called the THEORY OF BIOGENESIS. This was first proposed by a German scientist named Rudolf Virchow in 1858.

2. Louis Pasteur- ( 1822-1895 ) A French chemist, made numerous contributions to the newly emerging field of microbiology, and, in fact, contributions are considered by many people to be the foundation of the science of microbiology and a cornerstone of modern medicine.

Listed below are his most significant contributions: a. While attempting to discover why wine becomes contaminated with undesirable substances, Pasteur discovered what occurs during alcoholic fermentation. He also demonstrated that different types of microbes produce different fermentation products. For example, yeasts convert the glucose in grapes to ethyl alcohol ( ethanol ) by fermentation, but certain contaminating bacteria, such as Acetobacter, convert glucose to acetic acid ( vinegar ) by fermentation, thus, ruining the taste of the wine. b. Through his experiments, Pasteur dealt the fatal blow to the theory of spontaneous generation. c. Pasteur discovered forms of life that could exist in the absence of oxygen. He introduced the term aerobes (organisms that require oxygen) and anaerobes ( organisms that do not require oxygen ). d. Pasteur developed a process (today known as pasteurization) to kill microbes that were causing wine to spoil. Pasteurization can be used to kill pathogens in types of liquids. It should be noted that pasteurization does not kill all of the microbes in liquids-just the pathogens. e. Pasteur discovered the infectious agents that caused the silkworm diseases that were crippling the silk industry in France. He also discovered how to prevent such diseases. f. Pasteur made significant contributions to the germ-theory of disease-the theory that specific microbes cause specific infectious diseases. For example, anthrax is caused by a specific bacterium ( Bacillus anthracis ), whereas tuberculosis is caused by a different bacterium ( Mycobacterium tuberculosis ).

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g. Pasteur championed changes in hospital practices to minimize the spread of disease by pathogens. h. Pasteur developed vaccines to prevent chicken cholera, anthrax, and swine erysipelas ( a skin disease ). It was the development of these vaccines that made him famous in France. Before the vaccines, these diseases were decimating chickens, sheep, cattle and pigs in that country-a serious economic problem. i. Pasteur developed a vaccine to prevent rabies in dogs and successfully used the vaccine to treat human rabies.

3. Robert Koch- ( 1843-1910 ) A German physician made numerous contributions to the science of microbiology.

Some of them are listed below. a. Koch made many significant contributions to the germ theory of disease. For example, he proved that the anthrax bacillus ( B. anthracis ), which had been discovered earlier by other scientists, was truly the causative agent of anthrax.

He accomplished this using a series of scientific steps that he and his colleagues had developed, these steps later became known as Koch’s Postulates. b. Koch discovered that B. anthracis produces spores, capable of resisting adverse conditions. c. Koch developed methods of fixing, staining, and photographing bacteria. d. Koch developed methods of cultivating bacteria on solid media. The term pure culture refers to a condition in which only one type of organism is growing on a solid culture medium or in a liquid culture medium in the laboratory; no other types of organisms are present. e. Koch discovered the bacterium ( M. tuberculosis ) that causes tuberculosis and the bacterium ( Vibrio cholera ) that causes cholera. f. Koch’s work on tuberculin ( a protein derived from M. tuberculosis ) ultimately led to the development of a skin test valuable in diagnosing tuberculosis.

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Figure 7: Koch’s Postulates Source:: https://ecampusontario.pressbooks.pub/microbio/chapter/how-pathogens- cause-disease/

4. Francesco Redi ( 1668 ) An Italian Physician, naturalist, biologist and poet. He is referred to as the “Father of Modern Parasitology”. He was the first person to challenge the theory of spontaneous generation by demonstrating that maggots come from eggs of flies.

5. John Needham ( 1745 ) Published a report of his own experiments, in which he briefly boiled broth infused with plant or animal matter, hoping to kill all preexisting microbes. He then sealed the flasks…This suggested that microbes were introduced into these flasks from the air.

6. Rudolf Virchow ( 1885 ) Used the theory that all cells arise from pre-existing cells to lay the groundwork for cellular pathology, or the study of disease at the cellular level. His work made it more clear that diseases occur at the cellular level. His work led to scientists being able to diagnose diseases more accurately.

7. John Tyndall ( 1869 ) Irish physicist, best known for his work on the scattering of light by atmospheric particles and on the absorption of infrared radiation by gases. He also did much to popularize science among laymen.

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8. Agostino Bassi ( 1834 ) Made an investigation of the silkworm disease which was causing serious economic losses in Italy and France. He was able to demonstrate that the disease was contagious and was caused by a microscopic, parasitic fungus.

9. Joseph Lister ( 1827-1912 ) He successfully introduced carbolic acid ( now known as phenol ) to sterilize surgical instruments and to clean wounds. Applying Louis Pasteur’s advances in microbiology, Lister championed the use of carbolic acid as an antiseptic, so that it became the first widely used antiseptic in surgery.

CELL STRUCTURE AND HOST PATHOGEN RELATIONSHIP There are two major categories of microbes: acellular microbes ( also called infectious particles ) and cellular microbes ( also called microorganisms ). You will learn about the structure of microorganisms.

Figure 8: Acellular and Cellular Microbes Source: https://slideplayer.com/slide/12801411/

EUKARYOTIC CELL STRUCTURE Eukaryotes ( eu-true, karyo- refers to a nut or nucleus ) are so named because they have a true nucleus, and that their DNA is enclosed by a nuclear membrane. Most animal and plant cells are 10 to 30 micrometers in diameter, about 10 times larger than most prokaryotic cells.

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Figure 9: Eukaryotic Cell Source:https://www.pinterest.ph/pin/504473595735343501/

Cell Membrane- the cell is enclosed and held intact by the cell membrane, which is also referred to as the plasma, cytoplasmic, or cellular membrane. Structurally, it is a mosaic composed of large molecules of proteins and phospholipids ( certain types of fats ). The cell membrane is like a skin around the cell, separating the contents of the cell from the outside world. The cell membrane regulates the passage of nutrients, waste products and secretions into and out of the cell. Because the cell membrane has the property of selective permeability, only certain substances may enter and leave the cell. The cell membrane is similar in structure and function to all of the other membranes that are found in eukaryotic cells.

Nucleus- the primary difference between prokaryotic and eukaryotic cells is that eukaryotic cells possess a true nucleus whereas prokaryotic cells do not. The nucleus controls the functions of the entire cell and can be thought of as the command center of the cell. The nucleus has three components: nucleoplasm, chromosomes, and a nuclear membrane. Nucleoplasm ( a type of protoplasm ) is the gelatinous matrix or base material of the nucleus. The chromosomes are embedded or suspended in the nucleoplasm. The membrane that serves as a skin around the nucleus is called the nuclear membrane, it contains holes ( nuclear pores ) through which large molecules can enter and exit the nucleus.

Cytoplasm- is a semi-fluid, gelatinous, nutrient matrix. Within the cytoplasm are found insoluble storage granules and various cytoplasmic organelles, including endoplasmic reticulum, ribosomes, golgi complexes, mitochondria, centrioles, microtubules, lysosomes and other membrane bound vacuoles. Each of these organelles has a highly specific function, and all of the functions are interrelated to maintain the cell and allow it to properly perform its activities.

The cytoplasm is where most of the cell’s metabolic reactions occur. The semifluid portion of the cytoplasm, excluding the granules and organelles, is sometimes referred to as the cytosol.

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Endoplasmic Reticulum- ( ER ) is a highly convoluted system of membranes that are interconnected and arranged to form a transport network of tubules and flattened sacs within the cytoplasm. Much of the ER has a rough, granular appearance when observed by transmission electron microscopy and is designated as a rough endoplasmic reticulum ( RER ). This rough appearance is caused by the many ribosomes attached to the outer surface of the membranes.

ER to which ribosomes are not attached is called smooth endoplasmic reticulum ( SER ).

Ribosomes- eukaryotic ribosomes are 18 to 22 nm in diameter. They consist mainly of rRNA and protein and play an important part in the synthesis of proteins.

Golgi Complex- also known as a Golgi apparatus or Golgi body, connects or communicates with the ER. This stack of flattened, membranous sacs completes the transformation of newly synthesized proteins into mature, functional ones and packages them into small, membraneenclosed vesicles for storage within the cell or export outside the cell ( exocytosis or secretion ).

Golgi complexes are sometimes referred to as packaging plants.

Lysosomes and Peroxisomes- lysosomes are small vesicles that originate at the Golgi complex. They contain lysozyme and other digestive enzymes that break down foreign material taken into the cell by phagocytosis ( the engulfing of large particles by amoebas and certain types of white blood cells called phagocytes ). These enzymes also aid in breaking down worn out parts of the cell and may destroy the entire cell by a process called autolysis is the cell is damaged or deteriorating. Lysosomes are found in all eukaryotic cells. Peroxisomes are membrane-bound vesicles in which hydrogen peroxide is both generated and broken down.

They are found in most eukaryotic cells, but are especially prominent in mammalian liver cells.

Mitochondria- the energy necessary for cellular function is provided by the formation of highenergy phosphate molecules such as adenosine triphosphate ATP. ATP molecules are the major energy-carrying or energy-storing molecules within cells. Mitochondria are referred to as the power plants, powerhouses, or energy factories of the eukaryotic cell, because this is where most of the ATP molecules are formed by cellular respiration.

Plastids- plant cells contain both mitochondria and another type of energy-producing organelle, called a plastid. Plastids are membrane-bound structures containing various photosynthetic pigments, they are the site of photosynthesis. Chloroplasts, one type of plastid, contain a green photosynthetic pigment called chlorophyll. Chloroplasts are found in plant cells and algae.

Cytoskeleton- present throughout the cytoplasm is a system of fibers, collectively known as the cytoskeleton. The three types of cytoskeletal fibers are microtubules, microfilaments ( actin filaments ) and intermediate filaments. All three types serve to strengthen, support and stiffen the cell, and give the cell its shape.

Cell Wall- some eukaryotic cells contain cell walls-external structures that provide rigidity, shape and protection. Eukaryotic cell walls, which are much simpler in structure that prokaryotic cell walls, may contain cellulose, pectin, lignin, chitin and some mineral salts ( usually found in algae ). The cell walls of algae contain a polysaccharide-cellulose- that is not found in the cell walls of plants. The cell walls of fungi contain a polysaccharide-chitin-that is not found in the cell walls of any other microorganisms. Chitin, which is similar in structure to cellulose, is also found in the exoskeletons of beetles and crabs.

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Flagella and Cilia- some eukaryotic cells possess relatively long, thin structures called flagella.

Such cells are said to be flagellated or motile, flagellated protozoa are called flagellates. The whipping motion of the flagella enables flagellated cells to swim through liquid environments, flagella are said to be whip-like. Flagella are referred to as organelles of locomotion ( cell membrane ).

OTHER EUKARYOTIC ORGANISMS: FUNGI Fungi have been studied systematically for 250 years, although ancient peoples learned of fermentation (enabled by fungi) thousands of years ago. Scientists who practice mycology, the study of fungi, are called mycologists. In the early days of microbiology, mycologists categorized fungi as plants because they resemble plants in general appearance (they have cell walls) and because both fungi and plants lack motility (neither can move under its own power).

Today, however, fungi and plants are considered two distinct groups of organisms because plants use chlorophyll to obtain nutrients and fungi do not. Fungi are heterotrophic: They absorb nutrients from organic matter and organic wastes (saprophytes) or tissues of other organisms (parasites). Many fungi are multicellular and are called molds. Yeasts are unicellular fungi.

Fungi can be both beneficial and harmful. For example, fungi called mycorrhizae are mutualistic and help roots of plants absorb water and minerals from the soil. The cellulose and lignin of plants are important food sources for ants; however, ants are unable to digest them unless fungi first break them down. Ants are known to cultivate fungi for that purpose. Some fungi are beneficial to humans as food (mushrooms). They are used in the preparation of food such as bread and beer (yeast). Fungi are also used to fight off bacterial diseases (antibiotics).

Some fungi can have a harmful effect because they feed on plants, animals, and humans, causing plants and animals to decay and spoil as a source of nutrients (rotting food). In humans, fungi cause various diseases such as athlete’s foot.

Figure 10: Fungi Source: https://brainly.in/question/11625970

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ALGAE Algae are very simple unicellular or multicellular eukaryotic organisms that obtain energy from sunlight (photoautotrophs). They live in various water environments (oceans and ponds) on moist rocks and trees, and in soil. Sexual reproduction occurs in most species of algae. In these species the algae reproduce asexually for generations until there is a change in environmental conditions; then the algae reproduce sexually. The algae that reproduce sexually will latter reproduce asexually. All algae reproduce asexually. Unicellular algae divide by mitosis and cytokinesis. Multicellular algae that contain thalli and filaments can fragment. Each new piece can form a thallus and a filament.

Figure 11: Algae Source:https://biologynotes3.blogspot.com/2017/12/differences-between-algae-and-fungi.html

PROTOZOA These organisms are members of the Kingdom Protista. There are about 20,000 known species of protozoa that live in water and soil. Some feed on bacteria while others are parasites and feed off their hosts.

Most protozoa are asexual and reproduce in one of three ways. These are: • Fission: Fission occurs when a cell divides evenly to form two new cells.

• Budding: Budding occurs when a cell divides unevenly.

• Multiple fission (schizogony): Multiple fission is when the nucleus of the cell divides multiple times before the rest of the cell divides. Forms around each nucleus when the nucleus divides then each nuclei separates into a daughter cell.

Some protists are sexual and exchange genetic material from one cell to another through conjugation, which is the physical contact between cells.

A protist can survive in an adverse environment by encapsulating itself with a protective coating called a cyst. The cyst defends the protist in extreme temperatures against toxic chemicals and even when there is a lack of oxygen, moisture, and food. Protists receive nutrients by breaking down organic matter (heterotrophic) and can grow in both aerobic and anaerobic environments, such as protists that live in the intestine of animals. Some protists, such as Euglena, receive nutrients from organic matter and through photosynthesis because they contain chlorophyll.

These protists are considered both algae and protozoa. Protists obtain food in one of three ways: • Absorption: Food is absorbed across the protist’s plasma membrane.

• Ingestion: Cilia outside the protist create a wave-like motion to move food into a mouth-like opening in the protist called a cytosome. An example is the paramecium.

• Engulf: Pseudopods (meaning “false feet”) on the protist engulf food, then pull it into the cell using a process called phagocytosis. An example of this type of protist is the amoeba.

Food is digested in the vacuole after the food enters the cell. The vacuole is a membrane-bound organelle. Waste products are excreted using a process called exocytosis.

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Figure 12: Protozoa Source: https://6636.stem.org.uk/pathogens5.html

AMOEBA- a type of cell or unicellular organism which has the ability to alter its shape, primarily by extending and retracting pseudopods. Amoebas do not form a single taxonomic group, instead, they are found in every major lineage of eukaryotic organisms.

Here are common amoebas: • Entamoeba histolytica: Also known as E. histolytica, this microorganism is transmitted between humans through the ingestion of cysts that are excreted in the feces of infected people. It is the causative agent of amebic dysentery.

• Naegleria fowleri: This ameba causes primary amebic meningoencephalitis (PAM) that results in headache, fever, vomiting, stiff neck, and loss of bodily control. N. fowleri enters the body through the mucous membranes (when the person swims in warm water) and travels to the brain and spinal cord.

• Acanthamoeba polyphaga: This ameba lives in water (including tap water) and infects the cornea of the eye leading to blindness. It can also cause ulcerations of the eye and the skin. A. polyphaga is also known to invade the central nervous system, resulting in death.

Flagellates move by structures called flagella. They have two or more spindle shaped flagella in the front of the cell that they use to pull themselves through their environment. Food enters flagellates through a mouth-like grove called a cytosome.

Here are common flagellates: • Trichomonas vaginalis: Commonly known as T. vaginalis, this flagellate is the cause of trichomoniasis, which is a sexually transmitted disease.

T. vaginalis is found in the male urinary tract and the vagina of females.

• Giardia lamblia: This flagellate is commonly known as G. lamblia and causes giardiasis.

Giardiasis causes nausea, cramping, and diarrhea when food or water contaminated by fecal material is ingested. G. lamblia lives in the small intestines of humans and other mammals.

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Figure 13: Amoeba Source:https://rsscience.com/facts-about-amoeba/

HELMINTHS Helminths are parasitic, multicellular eukaryotic animals. The majority of these animals belong to the phyla Platyhelminthes and Nematoda. There are free living members of these phyla; however, in this section, only the parasitic organisms are discussed.

Many parasitic helminths do not have a digestive system and instead absorb nutrients from the food that is consumed by their host organism, the host’s body fluids, and the host’s tissues.

Parasitic helminths have a very simplistic nervous system because they have to respond to very few changes in their host’s environment. They lack or have reduced means of locomotion because they are transferred from one host to another. Parasitic helminths have a very complex reproductive system that produces fertilized eggs (zygotes) that infect the host organism. The life cycle of parasitic helminths that go through a developmental larval stage involves an intermediate host. Dioecious adult helminths are of one sex. That is, one individual has a male reproductive system and another has a female reproductive system. When these two adult helminths with different sex organs occupy the same host organism, sexual reproduction can occur. Monoecious adult helminths are hermaphroditic (an organism that has both female and male reproductive organs). Some of these monoecious helminths can fertilize themselves while others may fertilize each other.

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Figure 14: Helminth Source:https://blog.hemacare.com/dendritic-cells-role-in-fighting-helminth-infection

PROKARYOTIC CELL STRUCTURE Prokaryotic cells are about 10 times smaller than eukaryotic cells. A typical E. coli is about 1 micrometer wide and 2 to 3 micrometer long. Structurally, prokaryotes are very simple cells when compared with eukaryotic cells, and yet they are able to perform the necessary processes of life. Reproduction of prokaryotic cells is by binary fission-the simple division of one cell into two cells after DNA replication and the formation of a separating membrane and cell wall. All bacteria are prokaryotes, as are the archaea.

Figure 15: Prokaryotic Cell Source:https://micro.magnet.fsu.edu/cells/bacteriacell.html

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Cell Membrane- enclosing the cytoplasm of a prokaryotic cell is the cell membrane ( also known as the plasma, cytoplasmic or cellular membrane ). This membrane is similar in structure and function to the eukaryotic cell membrane. Chemically, the cell membrane consists of proteins and phospholipids. Being selectively permeable, the membrane controls which substances may enter or leave the cell. It is flexible and so thin that it cannot be seen with a compound light microscope. However, it is frequently observed in transmission electron micrographs of bacteria. Many enzymes are attached to the cell membrane, and various metabolic reactions take place there.

Chromosome- the prokaryotic chromosome usually consists of a single, long, supercoiled, circular DNA molecule, which serves as the control center of the bacterial cell. It is capable of duplicating itself, guiding cell division, and directing cellular activities. A prokaryotic cell contains neither nucleoplasm nor a nuclear membrane. The chromosome is suspended or embedded in the cytoplasm. The DNA-occupied space within a bacterial cell is sometimes referred to as the bacterial nucleoid.

Cytoplasm- the semi liquid cytoplasm of prokaryotic cells consists of water, enzymes, dissolved oxygen ( in some bacteria ), waste products, essential nutrients, proteins, carbohydrates, and lipids- a complex mixture of all the materials required by the cell for its metabolic functions.

Cell wall- the rigid exterior cell wall that defines the shape of bacterial cells is chemically complex. The main constituent of most bacterial cell walls is a complex macromolecule polymer known as peptidoglycan ( also known as murein ) consisting of many polysaccharide chains linked together by small peptide ( protein ) chains. Peptidoglycan is only found in bacteria.

Glycocalyx- ( Slime Layers and Capsules ) a slimy, gelatinous material produced by the cell membrane and secreted outside of the cell wall. There are two types of glycocalyx . One type called a slime layer, is not highly organized and is not firmly attached to the cell wall. It easily detaches from the cell wall and drifts away. The other type of glycocalyx, called a capsule is highly organized and firmly attached to the cell wall. Capsules usually consist of polysaccharides, which may be combined with lipids and proteins, depending on the bacterial species.

Flagella- are thread-like, protein appendages that enable bacteria to move. Flagellated bacteria are said to be motile, whereas non flagellated bacteria are usually non motile. Bacterial flagella are about 10-20 nanometer thick, too thin to be seen with the light microscope.

Pili- ( Fimbriae )- are hair-like structures, most often observed on gram negative bacteria. They are composed of polymerized protein molecules called pilin. Pili are much thinner than flagella, have a rigid structure, and are not associated with motility.

Spores- a few genera of bacteria are capable of forming thick-walled spores as a means of survival when their moisture or nutrient supply is low. Bacterial spores are known as endospores and the process by which they are formed is called sporulation.

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Figure 16: Comparison of a Eukaryotic Cell from Prokaryotic Cell Source:https://www.expii.com/t/eukaryotic-cell-definition-examples-10021

CELLULAR INFECTIOUS AGENTS VIRUSES- complete virus particles, called virions, are very small and simple in structure. Most viruses range in sizes from 10 to 300 nm in diameter, although some-like ebola virus-can be up to 1 micrometer in length. The smallest virus is about the size of the large hemoglobin molecule of a red blood cell.

5 Specific Properties: a. The vast majority of viruses possess either DNA or RNA, unlike living cells, which possess both. b. They are unable to replicate (multiply) on their own, their replication is directed by the viral nucleic acid once it has been introduced into a host cell. c. Unlike cells, they do not divide by binary fission, mitosis or meiosis. d. They lack the genes and enzymes necessary for energy production. e. They depend on the ribosomes, enzymes and metabolites ( building blocks ) of the host cell for protein and nucleic acid production.

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Figure 17: Viruses that affects Humans Source:https://www.khanacademy.org/science/biology/biology-of-viruses/virus-biology/a/animal-viruses-hiv

A virus (Latin for “poison”) is an obligate intracellular parasite that can only replicate inside a living host cell. Once inside the living host cell, a virus becomes integrated in the metabolism of its host, making a virus difficult to control by chemical means. You cannot kill a virus with antibiotics. Drugs that destroy the host’s ability to be used by a virus for replication tend to also be highly toxic and have a negatively and sometimes deadly effect on the host cell. Before a virus enters a cell, it is a free virus particle called a virion. A virion cannot grow or carry out any biosynthetic or biochemical function because it is metabolically inert. Viruses are not cells. They vary in size from 20 nanometers (polio virus) to 300 nanometers (smallpox virus) and cannot be seen under a light microscope. In 1933, microbiologist Wendell Stanley of the Rockefeller Institute for Medical Research showed that viruses could be regarded as chemical matter rather than as living organisms.

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Figure 18: Virus Source:https://www.semanticscholar.org/paper/Molecular-biology-of-giant-viruses'-DNA-replicationEvripioti/76991ec208ff3a0a93a8145ce5ccedfc630bea53

VIROIDS In 1971, plant pathologist O.T. Diener discovered an infectious RNA particle smaller than a virus that causes diseases in plants. He called it a viroid. Viroids infect potatoes, causing potato, spindle tuber disease. They infect chrysanthemums, stunting their growth. Viroids cause cucumber pale fruit disease. Millions of dollars are lost each year in crop failures caused by viroids.

A viroid is similar to a virus in that it can reproduce only inside a host cell as particles of RNA. However, it differs from a virus in that each RNA particle contains a single specific RNA. In addition, a viroid does not have a capsid or an envelope. Some viruses do not have an envelope.

Figure 19: Virus, Viroids and Prions Source:https://medium.com/@nehamicrobio83/difference-among-virus-virion-viroid-virusoid-and-prion-a01f22f06825

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PRIONS A prion is a small infectious particle that contains a protein. Some researchers believe that a prion consists of proteins without nucleic acids because a prion is too small to contain a nucleic acid and because a prion is not destroyed by agents that digest nucleic acids.

Prion diseases referred to as transmissible spongiform encephalopathies (TSEs) are progressive neurological diseases that are fatal to humans and animals.

Researchers believe that prions cause Creutzfeldt-Jakob disease. Creutzfeldt-Jakob disease is a neurological disease that causes progressive dementia first observed by Hans Gerhard Creutzfeldt and Alfon Maria Jakob in the 1920s. In 1976, Carlton Gajdusek won the Nobel prize for his work with the TSE Kuru. Kuru is characterized by progressive ataxia incapacitation and death.

In 1982, neurobiologist Stanley Prusiner proposed that proteins cause the neurological disease Scrapie, which is a degenerative neural condition in sheep. Prusiner named this infectious protein prion. Prions also cause other neurological diseases such as Kuru and GerstmannSträussler-Sheinker syndrome. However, scientists are still studying prions to learn their origins and how prions replicate and cause disease.

VIRULENCE The terms virulent and virulence tend to be confusing because they are used in several different ways. Sometimes virulent is used as a synonym for pathogenic. For example, there may be virulent ( pathogenic ) strains and avirulent (non pathogenic ) strains of a particular species. The virulent strains are capable of causing disease, whereas the avirulent strains are not. For example, toxigenic strains of the bacterium, Corynebacterium diptheriae ( strains that produce diphtheria toxin ) are virulent, whereas nontoxigenic strains are not. Encapsulated strains of the bacterium, S. pneumonia, can cause disease, but nonencapsulated strains cannot.

Source:

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Virulence Factors: https://www.slideshare.net/ripu123ripu/bacterial-virulence-factors-in-periodontology-99204657

VIRULENCE FACTORS: The physical attributes or properties of pathogen that enable them to escape various host defense mechanisms and cause disease are called virulence factors. Virulence factors are phenotypic characteristics that, like all phenotypic characteristics, are dictated by the organism’s genotype. Toxins are obvious virulence factors, but other virulence factors are not so obvious.

1.

Attachment- perhaps you have noticed that certain pathogens infect dogs but not humans, whereas others infect humans but not dogs. Perhaps you have wondered why certain pathogens cause respiratory infections, whereas others cause gastrointestinal infections. Part of the explanation has to do with the type or types of cells to which the pathogens is able to attach. To cause disease, some pathogens must be able to anchor themselves to cells after they have gained access to the body.

2.

Receptors and Adhesins- The general terms receptor and integrin are used to describe the molecule on the surface of a host cell that a particular pathogen is able to recognize and attach to. Often, these receptors are glycoprotein molecules. A particular pathogen can only attach to cells bearing the appropriate receptor. Thus, certain viruses cause respiratory infections because they are able to recognize and attach to certain receptors that are present on the cells that line the respiratory tract. Because those particular receptors are not present on cells lining the gastrointestinal tract, that virus is unable to cause gastrointestinal infections. Similarly, certain viruses cause infections in dogs, but not in humans because dog cells possess a receptor that human cells lack.

3.

Bacterial Fimbriae ( Pili )- are long thin , hair like, flexible projections composed primarily of an array of proteins called pilin. Fimbriae are considered to be virulence factors because they enable bacteria to attach to surfaces, including various tissues within the human body.

4.

Obligate Intracellular Pathogens- certain pathogens, such as Gramnegative bacteria in the genera Rickettsia and Chlamydia must live within host cells to survive and multiply, they are referred to as obligate intracellular pathogens ( or obligate intracellular parasites ). Rickettsia invade and live within endothelial cells and vascular smooth muscle cells.

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capable of both an intracellular and extracellular existence. Many facultative intracellular pathogens that can be grown in the laboratory on artificial culture media are also able to survive within phagocytes.

Intracellular Survival Mechanisms- phagocytes play an important role in 6. our defenses against pathogens. The two most important categories of phagocytes in the human body ( referred to as professional phagocytes ) are macrophages and neutrophils.

7.

Capsules- bacterial capsules are considered to be virulence factors because they serve an antiphagocytic function ( they protect encapsulated bacteria from being phagocytized by phagocytic white blood cells ). Phagocytes are unable to attach to encapsulated bacteria because they lack surface receptors for the polysaccharide material of which the capsule is made. If they cannot adhere to the bacteria, they cannot ingest them. Because encapsulated bacteria that gain access to the bloodstream or tissues are protected from phagocytosis, they are able to multiply, invade, and cause disease. Non encapsulated bacteria, on the other hand, are phagocytized and killed.

8.

Flagella- bacterial flagella are considered virulence factors because flagella enable flagellated ( motile ) bacteria to invade aqueous areas of the body that nonflagellated ( nonmotile ) bacteria are unable to reach. Perhaps flagella also enable bacteria to avoid phagocytosis-it is more difficult for phagocytes to catch a moving target.

Exoenzymes- the major mechanisms by which pathogens cause disease 9. are certain exoenzymes or toxins that they produce. Some pathogens produce both exoenzymes and toxins. a. Necrotizing enzymes- many pathogens produce exoenzymes that destroy tissues, these are collectively referred to as necrotizing enzymes.

Notorious examples are flesh eating strains of S. pyogens, which produce proteases and other enzymes that cause very rapid destruction of soft tissue, leading to a disease called necrotizing fasciitis. b. Coagulases- is a virulence factor that causes clotting. Coagulases binds to prothrombin, forming a complex called staphylothrombin. The protease activity of thrombin is activated in this complex, causing the conversion of fibrinogen to fibrin. c. Kinases- also known as fibrinolysins, have the opposite effect of coagulase. Sometimes the host will cause a fibrin clot to form around A Self-regulated Learning Module

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pathogens in an attempt to wall them off and prevent them from invading deeper into body tissues. Kinases are enzymes that lyse ( dissolve ) clots, therefore, pathogens that produce kinases are able to escape from clots. d. Hyalurodinase- the “spreading factor” as hyalurodinase is sometimes called, enables pathogens to spread through connective tissue by breaking down hyaluronic acid, the polysaccharide “cement” that holds tissue cells together. Hyalurodinase is secreted by several pathogenic species of staphylococcus, streptococcus and clostridium. e. Collagenase- produce by certain pathogens, breaks down collagen ( the supportive protein found in tendons, cartilage and bones. This enables the pathogens to invade tissues. Clostridium perfringens, a major cause of gas gangrene, spreads deeply within the body by secreting both collagenase and hyalurodinase. f. Hemolysins- are enzymes that damage red blood cells ( erythrocytes ).

The lysis ( bursting or destruction ) of red blood cells not only harms the host but also provides the pathogen with a source of iron. g. Lecithinase- is an exoenzyme that causes destruction of host cell membranes. C. perfringens, the major cause of gas gangrene, is able to rapidly destroy extensive areas of tissue, especially muscle tissue. One of the enzymes produced by C. perfringens, called lecithinase, breaks down phospholipids that are collectively referred to as lecithin. This enzyme is destructive to cell membranes of red blood cells and other tissues. h. Toxins- the ability of pathogens to damage host tissues and cause disease may depend on the production and release of various types of poisonous substances, referred to as toxins. The two major categories of toxins are endotoxins and exotoxins. i. Endotoxin- septicemia ( often referred to as sepsis ) is a very serious disease consisting of chills, fever, prostration ( extreme exhaustion ),and the presence of bacteria or their toxins in the bloodstream. j. Exotoxin- are poisonous proteins that are secreted by a variety of pathogens, they are often named for the target organs that they affect. The most potent exotoxins are neurotoxins, which affect the central nervous system ( CNS ).

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Source: Bacterial Virulence Factors https://www.researchgate.net/figure/Pathogenesis-and-virulence-factor-of-Pseudomonasaeruginosa_tbl2_300477991

EMERGING AND REEMERGING INFECTIOUS DISEASES It was not so many years ago that scientists believed that they had infectious diseases “on the run”. They were confident that a combination of surveillance, quarantine, vaccines, antibiotics and other microbial agents marked the beginning of the end for pathogen-caused diseases. They were wrong!

Not only do “new” ( previously unknown ) infectious diseases continue to emerge, but other infectious diseases, once thought to be contained or eradicated, continue to reemerge. Causes of emerging diseases include changes in human demographics and behavior, ecological changes such as dams, deforestation and climate change, increased international travel, increased exposure to exotic animals, misuse of antibiotics and other antimicrobial agents and breakdown of public health measures.

Listed here are some of the infectious diseases that have emerged in the last 30 years: Avian Influenza ( Bird Flu ) E. Coli O157 infections ( including hemolytic uremic syndrome Ebola hemorrhagic fever Hantavirus pulmonary syndrome ( HPS ) A Self-regulated Learning Module

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Hendra virus infection HIV infection and AIDS Human monkeypox Lassa Fever Legionellosis Lyme Disease Causes of reemerging infectious diseases include pathogen mutations and genetic recombinations, acquired drug resistance, decreased compliance with vaccination policies and other breakdowns in public health measures, population shifts, war and civil conflicts, famine, floods, droughts and bioterrorism. Infectious diseases that have reemerged or shown up in new geographic areas in recent years include cholera, dengue fever, diphtheria, malaria and tuberculosis.

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UNIT 1: CHECK FOR FACTS AND UNDERSTANDING

EVALUATE: A. History and Importance of Microbiology: MULTIPLE CHOICE: Choose the best answer. (10 points) 1. Who among the following individuals is considered to be the “Father of Microbiology?” a. Anton van Leeuwenhoek b. Louis Pasteur c. Robert Koch d. Rudolf Virchow 2. The microbes that usually live on or in a person are collectively referred to as: a. Germs b. Indigenous microbiota c. Non pathogens d. Opportunistic pathogens 3. Microbes that live on dead and decaying organic material are known as: a. Indigenous microbiota b. Parasites c. Pathogens d. Saprophytes 4. The study of algae is called? a. Algaeology b. Botany c. Mycology d. Phycology 5. The field of parasitology involves the study of which of the following types of organisms? a. Arthropods, bacteria, fungi, protozoa and viruses b. Arthropods, helminths, and certain protozoa c. Bacteria, fungi, and protozoa d. Bacteria, fungi, and viruses 6. Rudolf Virchow is given credit for proposing which of the following theories? a. Abiogenesis b. Biogenesis c. Germ theory of Disease d. Spontaneous Generation 7. Which of the following statements is true? a. Koch developed a rabies vaccine b. Microbes are ubiquitous c. Most microbes are harmful to humans d. Pasteur conducted experiments that proved the theory of abiogenesis 8. Which of the following are even smaller than viruses? a. Chlamydias A Self-regulated Learning Module

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b. Prions and viroids c. Rickettsias d. Cyanobacteria 9. Who among the following individuals introduced the terms “aerobes” and “anaerobes?” a. Anton van Leeuwenhoek b. Louis Pasteur c. Robert Koch d. Rudolf Virchow 10. The use of living organisms or their derivatives to make or modify useful products or processes is called? a. Bioremediation b. Biotechnology c. Biology d. Recycling B. CELLS: EUKARYOTIC AND PROKARYOTIC MULTIPLE CHOICE: Choose the best answer. (10 points) 1. Plants differ from animals? a. An endoplasmic reticulum b. A central vacuole c. Golgi complexes d. Vesicles 2. Unlike those of prokaryotes, eukaryotic cell walls are composed of? a. Chitin b. Proteins and histones c. Cellulose fibers embedded in a matrix d. A carbohydrate matrix cross-linked by short polypeptides 3. The Golgi apparatus involved in? a. Producing lysosomes b. Packaging proteins into vesicles c. Transporting proteins that are to be released from the cell d. All of the above 4. Which type of cell has membrane bound organelles? a. Eukaryotic cells b. Plant cells c. Animal cells d. Bacteria cells 5. What is the main function of the smooth endoplasmic reticulum? a. It generates energy to drive other biochemical processes b. It is the site of destruction of unwanted biological materials c. It is the site of the modification of proteins following their translation from RNA d. It synthesises proteins using RNA as a template 6. Which of the following statements is True? a. Prokaryotic cells came before Eukaryotic cells

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b. Eukaryotic cells do not have a nucleus, Prokaryotic cells do c. Eukaryotic cells are simple, Prokaryotic cells are complex d. Prokaryotic cells are bigger than Eukaryotic cells 7. Which of the following would be examples of Eukaryotic cells a. Plants and Animals b. Animals and Bacteria c. Plants and Prokaryotes d. Prokaryotes and Animals 8. Which of the following are involved with the movement or transport of materials or organelles throughout the cell? a. Cytoskeleton b. Rough endoplasmic reticulum c. Smooth endoplasmic reticulum d. All of the choices are true 9. Which is not true of Eukaryotic cells? a. They contain many organelles in the cytoplasm b. They contain ribosomes that are smaller than those of prokaryotic cells c. A true nucleus contains the chromosomes d. Eukaryotic cells contain membrane-bounded compartments 10. Cells that do NOT produce cell walls are a. Animal cells b. Prokaryotic cells c. Bacteria d. Plant cells

TRUE OR FALSE. Identify whether the following statements are true or false. (15 points) 1. Fossil evidence suggests that the first cell came into existence on earth about 6 million years ago.

2. Creating the first cell was a relatively quick process, but the evolution of eukaryotic cells took a long, long time.

3. The first cells somewhat resembled modern bacteria in shape and form.

4. The word karyon in the term 'eukaryotic', means 'nut' or 'kernel'.

5. Robert Hooke was able to see eukaryotic cells though his microscope.

6. The kingdom 'Monera' contains a mixture of prokaryotic and primitive eukaryotic cells.

7. Prokaryotic cells have no membranes between them and the outside world.

8. Fungi are more like eukaryotes than prokaryotes.

9. Some prokaryotic cells have flagella at one end, but some don't.

10. The genetic material in prokaryotic cells is very primitive and only consists of RNA, not DNA. 11. Plasmids are only found in bacteria with flagella.

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12. Binary fission is a method of cell division seen in prokaryotes.

13. All eukaryotic cells have a plasma (cell) membrane.

14. A nucleus contains histones and DNA. 15. Meiosis in eukaryotes usually produces haploid cells at the end of the double cell division.

EXPLAIN: In ten ( 10 ) sentences, Discuss the importance of Microbiology to your course. ( 20 Points ).

ELABORATE: Open discussion in Google Meet. ( Importance of Microbiology )

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Reference: LABORATORY SAFETY (Adapted from Safety in Academic Chemistry Laboratories, prepared by the American Chemical Society Committee on Chemical Safety). Source: https://drive.google.com/file/d/1OIl5Rj4dm6- z4DwmZ8uLU9flV_tQheOq/view?usp=sharing

In any clinical setting or laboratory course, familiarity with the fundamentals of laboratory safety is of vital importance. A laboratory room can be a dangerous place in which to work.

Understanding potential hazards will eliminate if not to decrease untoward hazards. Included in this manual are notes or cautions that point out some specific hazards and warnings. It is your responsibility, together with your Instructor, to make sure that all laboratory works is carried out in a safe manner. Your laboratory instructor will advise you of the specific rules for your laboratory. The following list of safety guidelines should be strictly observed at all times while in the laboratory room or when doing activities: a. SAFETY GUIDELINES 1) Always wear approved safety glasses or goggles. This sort of eye protectors must be worn at all times when inside the laboratory. Even if you are not actually carrying out an experiment, a person near you might have an accident that could endanger your eyes hence, eye protection is essential.

2) Keep in mind the location of Eyewash Facilities. If there are eyewash fountains (or sinks fitted with flexible hose) in your laboratory, you should determine which one is nearest to you before you start to work. In case any chemicals enter your eyes, go immediately to the eyewash fountain and flush your eyes and face with large amounts of water. b. FIRES 1) Use care with open flames in the laboratory. Because a laboratory course always deals with flammable substances, the danger of fire is frequently present. Because of this danger, exercise supreme caution when you light matches ore use any open flame.

DO NOT PLAY WITH OPEN FLAME. 2) Learn the location of fire extinguishers and fire showers. In case of fire, you should learn immediately where the nearest fire extinguisher and shower rooms are, you should know how these safety devices are operated, particularly the fire extinguisher. If there is fire, the best advice is to get away from it and let the instructor or laboratory assistant take care of it. DON’T panic. Should your clothing catch fire, DO NOT RUN! Walk purposely towards the fire shower station or the nearest sink hose. Running will fan the flames and intensify it.

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c. SOLVENTS: THEIR HAZARDS 1) Avoid contact with organic solvents and corrosive chemicals. It is essential to remember that most organic solvents are flammable (e.g. ethyl alcohol, benzene, acetone, etc.) and will burn if they are exposed to an open flame or a match. Corrosive chemicals, such as Sulphuric acid, are just as dangerous, but manifest their hazardous nature in other, subtler ways. Handle them with care. MINIMIZE YOUR EXPOSURE. Minimize any direct exposure to organic solvents and treat them with respect. The laboratory room should be well ventilated. Normal cautious handling of solvents should not cause any health problem. Evaporate volatile solutions in a fume hood. Another sensible precaution is to wear polyethylene gloves or surgical gloves when working with solvents.

2) If you are pregnant, you may want to consider taking this course at a later time.

Some exposure to organic fumes is inevitable, and any possible risk to an unborn baby should be avoided.

3) Do not breath solvent vapors. If you want to check the odor of a substance you should pass a stopper or spatula moistened with the substance (if it is a liquid) under your nose. Alternatively, you may hold the substance away from you and waft the vapors toward you with your hand. YOU SHOULD NEVER HOLD YOUR NOSE OVER THE CONTAINER AND INHALE DEEPLY.

d. WASTE DISPOSAL 1) Do not place any inorganic and organic liquids or solids into sinks; use waste containers. Many chemicals, especially organic substances are toxic, flammable, and difficult to degrade, it is not acceptable to dispose of organic solvents or solids by pouring them down the sink. The appropriate disposal method for wastes is to place them into appropriately labelled wastes containers and they should be disposed of safely either by incineration or by burial in a designated hazardous-waste dump by your particular laboratory personnel. ● NON HAZARDOUS SOLIDS such as paper, plastics and corks can be placed into an ordinary waste basket or trash can. ● BROKEN GLASSWARE should be put into a container specifically designated for broken glassware. ● ORGANIC SOLIDS AND INORGANIC SOLIDS that are not turned in or any other solids should be disposed of in the container designated for each of them. ● HALOGENATED and NON-HALOGENATED SOLVENTS should be disposed of in the container designated for each of them. ● STRONG INORGANIC ACIDS AND BASES. Strong acids such as hydrochloric, Sulphuric, and nitric acid and strong bases such as sodium and potassium hydroxide should be neutralized, diluted with water, and poured down the drain.

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● HEAVY METALS. Many heavy metal ions such as mercury and chromium are highly toxic and should be disposed of into specifically designated waste containers. e. USE OF FLAMES. Check to see whether anyone in your vicinity is using flammable solvents before you ignite any open flame. If someone is using a flammable solvent, move to a safer location before you light your flame. f. INADVERTENTLY MIXED CHEMICALS. To avoid unnecessary hazards of fire and explosion, NEVER POUR EXTRA REAGENT BACK INTO A STOCK BOTTLE. There is always a chance that you may accidentally pour back some foreign substance that will react explosively with the chemical in the stock bottle. Pouring reagents back into stock bottles is not only dangerous but it is also inconsiderate because you may introduce impurities that could spoil the experiment for the person using the stock reagent after you. This also means that you should not take more chemicals than you need. g.UNAUTHORIZED EXPERIMENTS, YOU SHOULD NEVER UNDERTAKE ANY UNAUTHORIZED EXPERIMENTS. The risk of an accident is high, particularly with an experiment that has not been completely checked to reduce the hazard. You should never work alone in the laboratory. The laboratory instructor or supervisor must always be present. h. FOOD IN THE LABORATORY. Because all chemicals are potentially toxic, you should avoid accidentally ingesting any toxic substance; therefore, never eat or drink any food in the laboratory. There is always the possibility that whatever you are eating or drinking may become contaminated with a potentially hazardous material. i. CLOTHING. YOU SHOULD ALWAYS WEAR SHOES IN THE LABORATORY. Open Toe shoes or sandals offer inadequate protection against spilled chemicals or broken glass. To protect yourself and your clothing, it is advisable to wear a full-length laboratory gown or apron.

Do not wear your best clothing in the laboratory because some chemicals can make holes or permanent stains on your clothing. Lastly, you should tie back hair that is shoulder length or longer, especially if you are working with a burner. j. FIRST AID: CUTS, MINOR BURNS, AND ACID OR BASE BURNS NOTE: any injury, no matter how small, must be reported to your laboratory instructor immediately.

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ACTIVITY 1 THE COMPOUND MICROSCOPE I. OBJECTIVE The students are expected to identify the different parts of a compound microscope and to describe their functions II. DISCUSSION Dutch lens maker during the 17th century came up with an instrument that could enlarge very tiny objects, and called it a microscope. Scientists agree that this invention led the turning point of medicine. For centuries the microscope has been improved to suit the diagnostic need of a laboratory scientist. It evolved from a simple microscope to a compound microscope employing different features. The dark-field microscope, Phase contrast microscope, fluorescent microscope and the electron microscope are the most commonly used microscope for medical purposes.

The basic components of a microscope are categorized into mechanical parts, illuminating parts, and magnifying parts.

III. MATERIALS Pencil, clean paper, transparent plastic ruler, compound microscope, glass slide, reference materials, PPEs SCORING RUBRIC for illustrations 5 points is given for every illustration made 5

Outstanding; the illustration shows genuine effort on the part of the maker and all parts are labelled with no misspelled words; no erasures

4

Excellent; the illustration shows above average effort on the part of the maker, 1 or 2 parts are not labelled and with misspelled words

3

Good; the illustration shows average effort on the part of the maker; 3-4 parts are not labelled and with misspelled words

2

Fair; the illustration shows below average effort on the part of the maker; 5 or more parts are not labelled and with misspelled words

1

Poor; the illustration shows little effort on the part of the maker, and the illustration is not labelled

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5 POINTS FOR EACH QUESTION

2 POINTS IS GIVEN FOR EVERY TERM CORRECTLY DEFINED

5

OUTSTANDING; no mistakes identified

4

EXCELLENT; 2 mistakes or missing concepts identified

3

GOOD; 3 mistakes or missing concepts identified

2

FAIR; 4 mistakes or missing concepts identified

1

POOR;5 mistakes or missing concepts is identified

0

The answer is totally different from the expected response

2

All concepts are defined

1

A concept is missing

0

The definition is totally different from the expected response

IV. ILLUSTRATIONS AND DRAWINGS A. Label the parts of a compound microscope according to its Mechanical, Illuminating, and Magnifying Parts. ( 17 Points ) MECHANICAL PARTS: 1._________________ 2._________________ 3._________________ 4._________________ 5._________________ 6._________________ 7._________________ 8._________________ 9._________________ 10._________________ 11._________________ 12._________________ ILLUMINATING PARTS: 13._________________ 14._________________ 15._________________ MAGNIFYING PARTS: 16._________________ A Self-regulated Learning Module

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17. _________________

B. QUESTIONS FOR RESEARCH 1.

What is the principle of the following types of microscopy? ( 5 Points each ) ( Maximum of Five sentences only ) ( 3 Points for References )

a. Bright-field

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b. Dark Field

c. Phase Contrast

d. Flourescent

e. Electron

2.

Define the following microscopy terms

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a. total magnification

b. Resolution

c. Contrast

d. Binocular microscope

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UNIT II MICROBIAL MECHANISMS OF PATHOGENICITY Objectives: After studying this unit, you should be able to: 1.

2.

3.

4.

Enumerate the steps in pathogenesis.

Describe the transmission of infection.

Define epidemiology and differentiate different disease distribution.

Discuss virulence and virulence factors.

By definition, microbes are too small to be seen with the unaided eye. How is it possible for such tiny organisms and infectious particles to cause disease in plants and animals, which are gigantic in comparison to microbes? This chapter will attempt to answer that question, with emphasis on disease in humans. The prefix path-comes from the greek word “pathos” meaning disease. The word infection tends to be confusing because the term is used in different ways.

An infection is the invasion of an organism’s body tissues by disease causing agents, their multiplication and reaction of host tissues to the infectious agents and toxins they produce.

ELABORATE: Open discussion in Google Meet. (Differentiate the following: Signs and Symptoms, Communicable and Contagious diseases, Local and Systemic infections, Primary and Secondary infections ) ENGAGE: In your own words, give five ( 5 ) sentences on how infection in the body happens. ( 10 Points )

1. Requirements for Infection Once a pathogen has gained entrance to the body, the course of an infectious disease has 4 periods or phases: a. The incubation period- is the time that elapses between arrival of the pathogen and the onset of symptoms. The length of the incubation period is influenced by many factors, including the overall health and nutritional status of the host, the immune status of the host ( whether the host is immunocompetent or immunosuppressed ), the virulence of the pathogen, and the number of pathogens that enter the body. b. The prodromal period- is the time during which the patient feels “out of sorts” but does not yet experience actual symptoms of the disease. Patients may feel like they are “coming down with something” but are not yet sure what it is. c. The period of illness- is the time during which the patient experiences the typical symptoms associated with that particular disease ( examples are sore throat, headache, sinus congestion ). Communicable diseases are most easily transmitted during the third period.

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d. The convalescent period- is the time during which the patient recovers. For certain infectious diseases, especially viral respiratory diseases, the convalescent period can be quite long. Although the patient may recover from the illness itself, permanent damage may be caused by destruction of tissues in the affected area. For example, brain damage may follow encephalitis or meningitis, paralysis may follow after poliomyelitis and deafness may follow after ear infections.

Figure 20: Periods of Infectious Disease Source:http://www.vce.bioninja.com.au/aos-2-detecting-and-respond/defence-against-disease/

Steps in the Pathogenesis of Infectious Diseases: In general, the pathogenesis of infectious diseases often follows the following sequence: a. Entry- of the pathogens into the body. Portals of entry include penetration of skin or mucous membranes by pathogen, inoculation of the pathogen into the bodily tissues by an arthropod, inhalation ( into the respiratory tract ), ingestion ( into the gastrointestinal tract ), introduction of the pathogen in the genitourinary tract, or introduction of the pathogen directly into the blood ( through blood transfusion, or the use of shared needles by intravenous drug abusers ). b. Attachment- of the pathogen to some tissues within the body. c. Multiplication- of the pathogen. The pathogen may multiply in one location of the body, resulting in a localized infection ( ex. Abscess ) or it may multiply throughout the body ( a systemic infection ). d. Invasion or spread of the pathogen. e. Evasion of host defenses. f. Damage to host tissues. The damage may be so extensive as to cause the death of the patient.

It is important to understand that not all infectious diseases involve all these steps. For example, once ingested, some exotoxin-producing intestinal pathogens are capable of causing disease without adhering to the intestinal wall or invading tissue.

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Figure 21.Infection of Disease Source:https://www.longdom.org/open-access/a-review-on-infectious-pathogens-and-mode-of-transmission.pdf

2. Transmission of Infection Modes of Transmission: The three principal routes by which pathogens involved in health care acquired infections are transmitted are contact, droplet and airborne.

Contact Transmission 2 types of contact transmissions: a. Direct Contact Transmission- pathogens are transferred from one infected person to another person without a contaminated intermediate object or person. b. Indirect Contact Transmission- happens when pathogens are transferred via a contaminated intermediate object or person.

Droplet Transmission- respiratory droplets carrying pathogens transmit infection when they travel from the respiratory tract of an infectious individual ( by sneezing, coughing ) to susceptible mucosal surfaces of a recipient. Droplets traditionally have been defined as being larger than 5 micrometers in size.

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Airborne Transmission- occurs with dissemination of either airborne droplet nuclei or small particles containing pathogens. Traditionally, airborne droplets are defined as being less than or equal to 5 micrometers in size.

In order for a pathogen to infect a host, there must be a susceptible host for the disease to be transmitted. If a host’s resistance is low (resistance is the ability to ward off disease), its susceptibility increases (its chances of becoming infected increase). Primary defense mechanisms of the body for resistance include intact skin (no cuts or abrasions), mucous membranes, a good cough reflex, normal gastric juices, and normal bacterial flora. If a microorganism penetrates these defenses the development of a disease.

Epidemiology Epidemiology is the study of the distribution and determinants of diseases or conditions of a population. The word originated from the two Greek words epi (“among”) and demos (“people”), or “among the people.” An epidemiologist is a scientist trained to identify and prevent diseases in a given population. They are concerned with the etiology, or the specific cause of a disease in a given population. Epidemiologists use this information to design ways of preventing and controlling outbreaks of disease.

Epidemiology is considered a branch of microbiology because microorganisms cause many diseases. It can also be considered a branch of ecology because of the relationship among pathogens, their hosts, and the environment. The science of epidemiology provides the methods and information that are used to understand and control outbreaks of diseases in human populations, making it important for public health. An epidemiologist is a person who is trained to identify and prevent diseases in a given population or a medical doctor who is trained to identify and treat diseases in individual people. Epidemiologists are concerned with the frequency or prevalence of diseases in a given population. An epidemiologist will identify the factors that cause disease or how that disease is transmitted and how the spread of communicable and non communicable diseases can be prevented. The incidence rate of a disease is the total number of new cases seen within a calendar year. The prevalence of a disease is the number of people infected at any given time. The prevalence rate is the total number of old and new cases of a disease. Frequencies are also expressed as proportions of the total population. The morbidity rate is the state of illness or the number of people in a given population that are ill.

This is expressed as the number of cases per 100,000 people per year. The mortality rate is the number of people that are dead. This is measured as the number of deaths from a specific cause per 100,000 people per year.

Classification of Diseases: a. Sporadic Diseases- is a disease that occurs only occasionally ( sporadically ) within the population of a particular geographic area. Quite often, certain diseases occur only sporadically because they are kept under control as a result of immunization programs and sanitary conditions. It is possible for outbreaks of these controlled diseases to occur, however, whenever vaccination programs and other public health programs are neglected. b. Endemic Diseases- are diseases that are always within the population of a particular geographic area. The number of cases of the disease may fluctuate over time, but the diseases never die out completely. The actual incidence of an endemic disease of an endemic disease at any particular time depends on a balance among several factors, A Self-regulated Learning Module

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including the environment, genetic susceptibility of the population, behavioral factors, number of people who are immune, virulence of the pathogen, and reservoir or source of infection. c. Epidemic Diseases- ( outbreak ) is defined as a greater than usual number of cases of a disease in a particular region, usually occurring within a relatively short period of time.

An epidemic does not necessarily involve a large number of people, although it might. d. Pandemic Diseases- is a disease that is occurring in epidemic proportions in many countries simultaneously-sometimes worldwide.

3. Principles of Diseases a. Signs Vs. Symptoms A symptom of a disease is defined as some evidence of a disease that is experienced or perceived by the patient-something that is subjective. Examples of symptoms include any type of ache or pain, a ringing in the ears ( tinnitus ), blurred vision, nausea, dizziness, itching and chills. Diseases including infectious diseases , may be either symptomatic or asymptomatic. A symptomatic disease ( clinical disease ) is a disease in which the patient is experiencing symptoms. An asymptomatic disease ( or subclinical disease ) is a disease that the patient is unaware of because he or she is not experiencing any symptoms.

A sign of a disease is defined as some type of objective evidence of a disease. For example, while palpating a patient, a physician might discover a lump or an enlarged liver ( hepatomegaly ). Other signs of diseases include abnormal heart or breath sounds, blood pressure, pulse rate and laboratory results as well as abnormalities that appear on radiographs, ultrasound studies or computed tomography scans. b. Communicable Vs. Contagious A communicable disease is a contagious one. The effect is external. If someone catches the illness, they can sick and spread the pathogen-be it a cold, virus or some other disease causing agent- onto the next person. Infectious diseases are caused by microscopic germs ( such as bacteria or viruses) that get into the body and cause problems. Some but not all infectious diseases spread directly from one person to another. Infectious diseases that spread from person to person are said to be contagious. c. Local Vs. Systemic Infection Once an infectious process is initiated, the disease may remain localized to one site or it may spread. Pimples, boils and abscesses are examples of localized infections.

If the pathogens are not contained at the original site of infection, they may be carried to other parts of the body by way of lymph, blood or in some cases, phagocytes. When the infection has spread throughout the body, it is referred to as either a systemic infection or a generalized infection. For example, the bacterium that causes tuberculosis-Mycobacterium tuberculosis-may spread to many internal organs, a condition known as military ( disseminated ) tuberculosis. d. Primary Vs. Secondary Infection One infectious disease may commonly follow another, in which case the first disease is referred to as a primary infection and the second disease is referred to as a secondary infection. For example, serious cases of bacterial pneumonia frequently follow relatively mild viral respiratory infections. During the primary infection, the virus causes damage to the ciliated epithelial cells that line the respiratory tract. Because the ciliated epithelial cells were damaged by the virus, they are unable to clear the bacteria from the lungs. The bacteria then multiply and cause pneumonia. In this

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example, the viral infection is the primary infection and bacterial pneumonia is the secondary infection.

Latent Infection- the residence in the body of a specific infectious agent without any manifested symptoms. The symptomless incubation period, which in certain diseases, notably measles and smallpox, is fairly definite in length, is a period of latency in infection. An infectious disease may go from being symptomatic to asymptomatic and then, sometimes later, go back to being symptomatic. Such diseases are referred to as latent infections, from the greek word “latens'' meaning to lie hidden.

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UNIT 2. CHECK FOR FACTS AND UNDERSTANDING EVALUATE: Multiple choices: Write the letter of your choice in your answer sheets.

A. Transmission of Infection (10 points) 1. Microorganisms that cause disease are called? a. Microbes b. Flora c. Pathogens d. Bacilli 2. The smallest microbe is? a. Virus b. Bacterium c. Yeast d. Spirochete 3. Examples of illnesses caused by viruses are a. Syphilis b. AIDS and Hepatitis c. Malaria and Amoebiasis d. Ringworm and athlete's foot 4. Individuals who can transmit a disease but do not show symptoms of the disease are known as a. Immunosuppressed b. Carriers c. Incubators d. Saprophytes 5. Microorganisms get into the body through a. Portals of entry b. Portals of exit c. Fomites d. Common vehicles 6. Infection can be transmitted by a. Touching sterile items b. Disinfecting equipment c. Blood and bodily fluids d. Wearing gloves 7. An example of indirect contact with a pathogen is a. Person to person contact b. Hand contact with a contaminated object c. Contact with an insect that transmits disease d. Body fluids or sexual contact 8. An example of a droplet transmission by disease is by a. Coughing, sneezing, or talking b. Germs carried through the ventilation system c. Microbes carried by moisture and dust in the air A Self-regulated Learning Module

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d. Inhaling the odor of unpleasant excretions 9. Hepatitis A is transmitted by: a. Blood and body fluid exposure b. Feces and saliva c. Contaminated seafood d. Contaminated meat 10. Hepatitis B is transmitted by: a. Blood and body fluid exposure b. Feces and saliva c. Contaminated seafood d. Contaminated meat EXPLORE: B. Epidemiology: Identification: Identify the following descriptions whether they refer to an endemic, epidemic, sporadic and pandemic. (10 points) 1. A widespread occurrence of an infectious disease in a community at a particular time.

2. This occurs only in a few scattered places.

3. These are diseases seen occasionally.

4. Numbers of cases fluctuate over time.

5. This refers to diseases with greater than usual cases in a region.

6. This is regularly found among particular people in a certain area.

7. The infection is constantly maintained in a geographical area.

8. This is a rapid spread of disease to a large number of people in a given population.

9. This occurs at irregular intervals in a certain place.

10. An epidemic spread over multiple countries Sign or Symptom: Classify whether the following examples are ( A ) signs of symptoms. (10 points)

( B )

1. Runny nose 2. Sinus pain from congestion 3. Spots and blisters 4. Fatigue 5. Poor wound healing 6. Thirst 7. Fast heart rate 8. Loss of taste or smell 9. Fever 10. Thirst

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EXPLAIN: What is the importance of Epidemiology to the medical field? ( 10 Points ) ( Maximum of five ( 5 ) sentences )

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ACTIVITY 2 INSTRUMENTS USED IN MICROBIOLOGY AND PARASITOLOGY

I.

OBJECTIVE

The students are expected to identify, describe, and cite the functions of the different glassware, apparatus, and equipment used in microbiology so that they will properly use them in microbiological experiments

II.

DISCUSSION

Instruments are essential to hasten and to make work more efficient. Low knowledge of equipment may lead to wrong use that may lead to erroneous results. In microbiological laboratory, various instruments are used for varied tasks. They may be under heating instruments like an incubator, a water bath, or an alcohol lamp, while others are used for storage like a refrigerator. Well equipped with these knowledge is essential not only to the quality of results obtained in experimentation but also for the safety of the ones using these equipment.

III.

MATERIALS Pencil, PPEs (lab gown) Test tubes, screw tubes, Petri dish, glass slide with cover sip, beaker, Erlenmeyer flask, inoculating loop, inoculating needle, forceps/pincers, staining rack, test tube rack, incubator, alcohol lamp, Durham tube, water bath, stirring rod, test tube holder, refrigerator, hot plate

Criteria

Highest Possible Score

Drawing looks similar to what was observed and/or taught.

2x12 drawings

Drawing is accurately labeled, including the use.

2x12 drawings

Drawing is legible and large enough to see all details.

2x12 drawings

Description and use of the apparatus

2x12 functions

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References

4

TOTAL

100

IV.

PROCEDURES and DRAWINGS 1.

Draw the materials stated above and give their use/uses in microbiology laboratory

Name: TEST TUBE

Name: SCREW CAPPED TUBES

Description & use/s:

Description & use/s:

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Name: PETRI DISH

Name: GLASS SLIDES WITH COVER SLIP

Description & use/s:

Description & use/s:

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Name: BEAKER

Name: ERLENMEYER FLASK

Description & use/s:

Description & use/s:

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Name: INOCULATING LOOP

Name: INOCULATING NEEDLE

Description & use/s:

Description & use/s:

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Name: FORCEPS/PINCERS

Name: STIRRING ROD

Description & use/s:

Description & use/s:

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Name: DURHAM TUBES

Name: STAINING RACK

Description & use/s:

Description & use/s:

2. Draw and label the parts of the following pieces of laboratory equipment and give a brief description and its uses.

Criteria

Highest Possible Score

Drawing looks similar to what was observed and/or taught.

4x3 drawings

Drawing is accurately labeled, including the use.

4x3 drawings

Drawing is legible and large enough to see all details.

4x3drawings

Use of the Laboratory

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Equipment/Process References

2

TOTAL

50

Name: WATER BATH Labels: Description:

Use/s:

Name: INCUBATOR Labels: Description:

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Use/s:

Name: HOT PLATE Labels: Description:

Use/s:

V. QUESTION FOR RESEARCH (10 points) What is the importance of using the proper tools and equipment with its intended application?

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Unit III CHARACTERISTICS OF DISEASE- CAUSING MICROORGANISM No one wants to give a friend a cold, so we always cover a sneeze with our hands. However, the germs are still on our hands and are transferred to door knobs, the food we touch, and a friend when we greet them with a handshake. In this unit, you’ll learn about diseases and how are spread and reproduction of pathogens from one person to another. You’ll also learn ways outbreaks of diseases are controlled and prevented by taking simple precaution.

Objectives: After studying this unit, you should able to: 1.

Describe appropriately the reproduction of important pathogens- bacteria, fungi and virus 2.

Describe comprehensively the role of bacterial pathogens

A.

BACTERIA

I. ANATOMY Bacteria are microorganisms and because of small size these cannot be visualized by naked eye. A bacterium shall characteristically have a cell envelope which includes a layered cell wall and external surface adherents. It is a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus which can cause diseases. A bacterium shall characteristically have a cell envelope which includes a layered cell wall and external surface adherents. The appendages of cell wall include flagellae— the organs of locomotion and fimbriae which help in adhesion of bacteria. Internally the bacterium has loose arrangement of DNA, i.e. nuclear apparatus surrounded by an amorphous cytoplasm which contains ribosomes. Mesosomes and inclusion granules are other structures present in bacteria. An artist’s impression of a bacterium is shown in picture below.

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Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

Shapes and Size of bacteria Bacteria can have any of the following three shapes: ● Sheroidal ( cocci) ● Cylindrical ( Bacilli or rods) ● Spirillar ( spirochetes) i.

Cocci - are true spheres with diameter ranging between 0.75 to 1.25 μm(and average of 1 μm).

ii.

Bacilli - vary in length from 2-10 times their width. THey are rod-shaped occurring singly or chains. They are notorious for their ability to cause infection in hospitals.

Several bacteria cause food poisoning. ( Pseudomonas, Klebsiella, Proteus, E.coli, Shigella and Salmonella)

iii. Coccobacilli - are very short bacilli iv. Filaments - are long threads of bacilli which have not separated into single cells. v.

Curved bacterial rods vary from small, comma shaped or mildly helical shaped organisms with only one curve such as Vibrio cholerae.

Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

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Arrangement of Bacterial Cells Cocci may occur in pairs as in diplococci. Some bacteria also have the tendency to cluster together in different patterns but in the absence of ant consistency in the patterns it is difficult to assign them any characteristic arrangement.

Bacteria are arranged: ✔ Single ✔ Diplococci - When arranged in pairs e.g. Streptococcus pneumoniae ✔ Staphylococcus- cluster or Staphylococcus epidermidis

grapelike

of

cocci

e.g

Staphylococcus

aureus,

✔ Streptococcus- chain and round bacteria attached to one another in chains, they cause sore throat.

Bacterial forms: A, diplococci; B, streptococci; C, staphylococci; D, bacilli; E, coccobacilli; F, fusiform bacilli;G, filamentous bacillary forms; H, vibrios; I, spirilla; J, sarcinae Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

The bacteria have: ✔ Surface adherents and appendages ✔ Cell Wall ✔ Cytoplasm ✔ Nucleus

II. GROWTH OF BACTERIA Bacteria have well defined requirements of proper nutrients, oxygen, pH and temperature.

Bacterial growth refers to an increase in bacterial cell numbers (multiplication) which results from a programmed increase in the biomass of the bacteria. Growth usually occurs asynchronously, all cells don’t divide at precisely the same moment. Most of the bacteria of A Self-regulated Learning Module

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medical importance will grow only if a source of organic material as a nutrient is available. For the growth of some bacteria a single source will suffice where some others are more exacting and require complex media where several organic matters are available. Bacteria do not have an obligatory life cycle. Whenever adequate nutrition and conducive environmental factors are available a bacterium enlarges and eventually divides by binary fission to form two daughter cells. The conversion of a parental cell into two daughter cells constitutes the bacterial life cycle and the time taken to complete one cell cycle is known as generation time or doubling time or replication time. Compared to the growth rates of most other living things, bacteria are notoriously speedy. The average generation (doubling) time is 30-60 minutes under optimum conditions. Longest generation time occurs in Mycobacterium leprae (10-30 days). Most pathogens have relatively shorter doubling time. Salmonella enteritidis and Staphylococcus aureus, both causes of food poisoning, double in 20–30 minutes. In the presence of fresh growth medium bacteria show the following four phases during their growth. ✔

Lag phase

✔

Log phase

✔

Stationary phase

✔

Decline phase

Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

The Lag Phase This phase is of a short duration in which bacteria adapt themselves to a new environment in such a way that the bacterial machinery brings itself in conformity with the nutrition available. It is a ‘flat’ period on the graph because newly inoculated cells require a period of adjustment, enlargement and synthesis. Enzymes and intermediates are formed and accumulate until they are present in concentration that permit growth to resume.

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The Log Phase (Exponential Phase) Regular growth of bacteria occurs in this phase which is also of short duration since the nutrients present in the medium are utilised by the bacteria and daughter cells. Once exhaustion of nutrients occurs, slowing down of growth also takes place and bacteria passes onto the stationary phase. The morphology of bacteria is best developed in this phase and organisms manifest typical biochemical characters. This phase will continue as long as cells have adequate nutrients and the environment is favourable. Hence, this phase can be prolonged by continuous supply of fresh nutrients at a constant and predefined rate.

The Stationary Phase This phase ensues when the culture conditions are so changed that further balanced growth and cell division cannot be sustained.

The Decline Phase The phase of decline is also called the death phase. Due to depletion of nutrients and accumulation of toxic end products the number of bacteria dying is much more than those dividing and hence there is a gradual decline in the total number of organisms. The growth curve now dips downwards. For a microbial cell, death means the irreversible loss of the ability to reproduce (growth and divide). The empirical test of death is the culture of cells on solid media; a cell is considered dead if it fails to give rise to a colony on any medium, provided a suitable culture medium is chosen. Synchronous Growth Refers to a situation in which all the bacteria in a culture divide at the same moment. It can be achieved by various methods such as selective filtration of older and young cells, alternate cycles of low and optimal incubation temperature, etc

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III. Genetics and Infectious Disease Genetics is the science of heredity. It includes the study of what genes are, how they carry information, how they replicate and pass information to future generations.

Bacterial variations have two types: 1. Phenotypic Variations -These are acquired during life of a bacterium and may not be passed down to progeny.

2. Genetic Variations - These variations influence the genetic composition of the bacterium and are transmitted to the next generation. The genetic variations can be due to two reasons: ✔ Alterations in the genome structure due to mutations ✔

Acquisition of genetic material through gene transfer.

Unlike eukaryotes where the gene transfer takes place through sexual reproduction—a mechanism which does not exist in bacteria, following four methods result into transfer of genetic material in bacteria: 1. Transformation: uptake of naked DNA 2. Transduction: infection by a nonlethal bacteriophage 3. Conjugation: mating between cells in contact 4. Protoplast fusion.

TRANSFORMATION Gene transfer by soluble DNA is transformation. Transformation requires that DNA be adsorbed by the cell, gain entrance to the cytoplasm and undergo recombination with the host genome.

Naturally competent transformable bacteria are found in several genera and include Bacillus subtilis, Haemophilus influenzae, Neisseria gonorrhoeae and Streptococcus pneumoniae.

Transformation of a bacterial cell by integration of DNA. (A) Competent recipient cell and transforming DNA. (B) Transforming DNA attacks competent cells and is degraded to single strand by cell nuclease. (C) Single strand DNA pairs with A Self-regulated Learning Module

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complementary bases of replicated and

recipient cell chromosome. (D) Integrated transforming DNA is transformed daughter cells are formed.

Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

TRANSDUCTION The type of gene transfer in which the DNA of one bacterial cell is introduced into another bacterial cell by viral infection is known as transduction. In transduction, adsorption of the bacteriophage to receptor sites on the bacterial surface is followed by injection into the cell of the DNA contained within the phage particle. If the phage is of virulent type, new phage particles will be synthesized and cell lysis shall result. However, if it is a temperate phage, a lysogenic response shall result and phage DNA shall be incorporated into the host chromosome in such a way that the two genomes are linearly contiguous. The phage genome in this stage is known as prophage. The host cell acquires a significant new property as a consequence of lysogeny because it becomes immune to infection by homologous phage.

Significance of Transduction. ✔

It transfers genetic material from one bacterial cell to another and alters the genetic characteristics of the recipient cell

✔ The incorporation of the prophage into a bacterial chromosome demonstrates a close evolutionary relationship ✔ The existence of a prophage in a cell for a long period of time suggests mechanism for the viral origin of cancer ✔ Specialized transduction provides a way to study gene linkage which can help in mapping of chromosomes.

Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

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LYSOGENIC CONVERSION In this the phage DNA becomes integrated with the bacterial chromosome as the prophage which multiplies synchronously with the host DNA and is transferred to the daughter cells. This process is called lysogeny and bacteria harbouring prophages are called lysogenic bacteria.

CONJUGATION Conjugation is defined as the transfer of DNA directly from one bacterial cell to another by a mechanism that requires cell-to-cell contact. For conjugation to occur, the donor and recipient cells must come in contact. The pili makes the initial contact between these two cells and then are retracted into the donor to draw two cells together until direct contact is made. Gradually, this combination is stabilized and significant force is required to separate them.

Genetic transfer Mechanism Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

INFECTIOUS DISEASE All organisms living in or on the bodies of other organisms and drawing their sustenance from them are considered parasites. Infection and disease are not synonyms and must be distinguished.Infection is the invasion or colonization of the body by pathogenic microorganisms. Disease of time, the host is said to be infected and if the infection causes the damage , the host is said to have an infectious disease.

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Pathogens Microbes capable of causing infections that result in disease are called pathogens. This characteristic is called pathogenicity of the organism.

Virulence Degree of pathogenicity of a microbe is referred to its virulence. Virulence is a quantitative term.

Infection of a susceptible animal with a highly virulent pathogen will almost always result in disease, whereas infection with a pathogen of low virulence will often fail to produce disease or only produce a mild disease when an infection results in any change from a state of health.

When microorganisms first associate with a host, the host is said to be contaminated. If the microbes establish themselves and grow and multiply for a period

Dynamics of infection Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

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B.

VIRUS

Virus is a quantitative measure of pathogenicity and is measured by the number of organisms required to cause disease, it is the degree of pathogenicity. Viruses are infectious agents too small to be seen with a light microscope. These were discovered in 1898 when bacteria free filtrate was shown to be causing disease. Since no particulate material was present in the filtrate, the agent was named as virus which in Latin means poison. Viruses are obligate intracellular parasites which means that they replicate (or multiply) only inside a living host cell.

I. Structure and Infection Cycles Size of Virus The viruses are measured in units of nanometre (nm) which is one-thousandth part of a micrometre or a one-millionth part of a millimetre. An Angstrom unit (A) is one-tenth of anm.

Viruses vary in diameter from 3 to 20 nm. Most viruses can be measured under an electron microscope by comparing their size with that of known sized latex particles. By employing various techniques it has been found that the poxviruses are largest in size and measure around 330 × 230 × 100 nm. Paramyxo- and herpesviruses vary in their diameter from 120-300 nm whereas influenza and adenoviruses have a diameter of 60-120 nm. The reo,toga and papova viruses have a diameter of 40-60 nm. The smallest viruses are picorna and parvoviruses which measure between 20-40 nm.

Morphology The viruses are composed of nucleic acids and proteins. The genome consists of a single nucleic acid which stores all the vital information required by the virus for its multiplication. The genome is surrounded by a shell or coat made of protein and called as capsid. The genome and capsid are collectively designated as nucleocapsid. Most of the viruses have an additional covering of lipid around their nucleocapsid which is known as the viral envelope. The complete virus particle is also called a virion. The term virion indicates that the virus is infectious as well as structurally intact.

Variations in shapes and sizes of viruses as compared to Esch. coli Source: R. R.Ichhpujani.,Essentials Microbiology

of

Bhatia, Medical

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Capsids These are the aggregates of repeating subunits arranged in a defined pattern. The subunits are called the capsomers. The capsomers may be made up of a few molecules of protein or, in their simplest form, may comprise one protein molecule.

The capsid has two functions: a. To protect the genome from external harmful factors or agents b. To introduce the viral genome into the host cells.

Similar functions are also performed by the lipid envelope of the virus.

Envelope In some viruses the capsid is covered by a lipid envelope. Sometimes proteins are also present in the envelope. The envelope proteins are invariably coded by the virus.

Depending on the virus, envelopes may or may not be covered by spikes (Fig 57.2). The spikes are carbohydrate-protein complexes that project from the surface of the envelope. The ability of certain viruses, such as the influenza virus, to clump red blood cells is associated with spikes.

Such viruses bind to red blood cells and form bridges between them. The resulting clumping is called haemagglutination and is the basis for several useful laboratory tests. Viruses whose capsid is not covered by an envelope are known as naked viruses. In naked viruses, it is the capsid that protects the nucleic acid from nuclease enzymes in biological fluids and that promotes attachment to susceptible host cells.

Naked virus (A) and enveloped virus with spikes (B) Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

Infection Cycle Viruses are obligate intracellular parasites. They do not possess any machinery which may be of help to them in synthesizing their nucleic acids or proteins, the genetic information for which

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is present in the genome of the virus. The viruses make use of the metabolic machinery of the host cell to undertake these processes. The replication of viruses takes place in a systematic manner and the whole event can be divided into a number of stages: 1. Attachment of virus to host cell - This process is also called binding or adsorption. This is a specific process wherein the structures present on the surface of the virus (sometimes called as ligands) bind to the receptors on the surface of the host cell.

2. Penetration - There are four possible mechanisms which the viruses use to enter a host cell. These are: 3. Translocation is the process by which the whole non enveloped virus enters the host cell by moving across the cell membrane.

4. Endocytosis is the engulfment of the virus by the invagination of a section of plasma membrane. This is a common mode of penetration of nonenveloped viruses.

5. Fusion is the endocytosis of enveloped viruses in which the envelopes of the viruses fuse with the membrane of the endosome.

6. Direct fusion of the virion envelope with the surface membrane of the cell also takes place in some of the families of viruses. Certain naked viruses (e.g. enteroviruses) are taken into the cells by viropexis, a process that is similar to phagocytosis 7. Uncoating - Immediately after entry into the host cell, interaction of the virion with host components and enzymes leads to a breakdown of the virion and exposure of the genome so that it can express.

8. Transcription of early mRNA - Transcription of early mRNA is required to produce certain enzymes and proteins which are necessary for the replication of viruses and that of late mRNA is for viral structural proteins.

9. Translation of early proteins- The viral mRNAs use the ribosomes of the host cell to synthesize proteins in the same way as the host mRNA. 10.

Replication of viral genome- Viruses reproduce from their nucleic acid, which directs not only its own replication but also the synthesis of virus specific proteins. Some of these are structural components of the virion, while others are proteins leading to the selective shutdown of synthesis of cellular macromolecules or enzymes involved in the synthesis of viral components.

11.

Transcription of late mRNA- This is required for the production of structural proteins. The cytoplasmic double stranded DNA carries DNA dependent RNA polymerase where ssRNA viruses make use of their own ssRNA dependent RNA polymerase to transcribe late mRNA. 12.

Translation of late proteins - These result after the synthesis of late mRNA and are usually the result of instructions of the newly formed progeny of the virus in the host cell.

13.

Assembly of virions - Virion assembly may take place in the host cell in the cytoplasm or the cell nucleus. Herpesviruses and adenoviruses are assembled in the nucleus whereas the picornaviruses and the poxviruses are assembled in the cytoplasm of the host cell.

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14.

Release - There are three mechanisms by which mature virions can escape from the host cell and start their cycle once again in new host cells. These are Cell Lysis, Cell Degeneration and Budding.

Budding of an enveloped virus Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

II. VIRAL PATHOGEN Pathogenicity of a virus (sometimes also called as its virulence) is the capacity to produce the disease. This encompasses entry into the host, multiplication therein and production of harmful effects which may prove fatal for the host at times. Unlike bacteria, viruses do not produce toxins and enzymes to damage the host cells. To cause disease a virus has to clear a number of hurdles that vary somewhat in type and number according to the virus concerned and its host. The following sequence of events is typical. The virus must: ✔

Invade the host

✔ Establish a bridgehead by replicating in susceptible cells at the site of inoculation Overcome the local defenses, e.g. lymphocytes and Interferon ✔ Spread from the site of inoculation to other areas often via bloodstream ✔ Undergo further replication in target areas which can be localised or generalised ✔

Exit from the host in large enough numbers to infect other susceptible hosts.

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Routes by which viruses enter the body Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

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C.

PARASITIC AND FUNGAL INFECTION

Parasites Parasites are organisms that live off other organisms or host to survive. Some parasites don’t noticeably affect their hosts. Others grow, reproduce or invade organ systems that make their host sick, resulting in a parasitic infection.

Fungi Opportunistic is the name given to the fungi that are normally saprophytic but may become pathogenic under special conditions. The term ‘asthenomycosis is sometimes used to describe diseases caused by such fungi. Strictly speaking most fungi are opportunistic but we will restrict the term to those organisms that become pathogenic when the host has an identifiable, preexisting disease, which may be local or general, spontaneous or iatrogenic.

Fungi Involved a.

b.

Yeast like fungi ✔

Candidia sps

✔

Torulopsis

✔

Cryptococcus

Filamentous fungi ✔

Aspergillus

✔

Mucor

✔

Cephalosporium

✔

Fusarium

✔

Geotrichum

✔

Scopulariopsis

Source of Infection It can be endogenous or exogenous. Endogenous. e.g. Candida albicans—a common saprophyte of intestinal tract and vagina. Exogenous. (widespread in nature). e.g. Mucor, Rhizopus, Absidia, Fusarium, etc.

Transition from Saprophytism to Pathogenicity The factors predisposing a saprophyte to pathogenicity are many and are as under: Physiological: ✔

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✔

Menstruation

Various diseases: ✔ Bacterial infections ✔ Malignant tumours ✔ Hemopathies ✔ Endocrinopathies especially diabetes and hypoparathyroidism. ✔ All diseases resulting in impairment of cellular and humoral immunity. ✔ Wetness and maceration of integument

Iatrogenic: ✔

Long-term antibacterial therapy

✔

Anti-tuberculous therapy

✔

Corticosteroid therapy for long time

✔

Immunosuppressants

✔

Oral contraceptives

✔

Indwelling intravenous catheters

✔

Open heart surgery

Sporangiospores Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

IMPORTANCE OF FUNGI Useful 1.

Fungi exist either as saprobes or parasites. Their preeminent ability to break down complex organic substrates of almost every type is an important and essential activity in the recycling of carbon and other elements in the cycle of life.

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2. Edible wild or domesticated varieties of mushrooms (Basidiomycetes) are important as food sources.

3. Fungi have been used to alter the texture, improve the flavour, increase the palatability and digestibility of natural or processed foods. Penicillium species has been used for ripening of certain varieties of cheese.

4. The yeasts are used for the fermentation purposes in production of beverages and juices as well as brewing and baking.

5. Products of fermentation yield industrial alcohol, fats and proteins. A mold (Fusarium) can produce within 48 hours, 12-15 grams of fat from a litre of 50% glucose solution.

6. Molds (such as Aspergillus species) are used in the production of citric, oxalic,gluconic and itaconic acid.

7. Actinomycetes and fungi are important sources of antibiotics such as penicillin,amphotericin B, adria mycin and bleomycin, etc.

8. Ergot which is used for inducing uterine contractions, controlling bleeding and treatment of migraine is a fungal product. Ergot is the resistant overwintering stage of Claviceps purpurea—a fungal pathogen of rye which transforms the seed of that plant into a compact spur-like mass of pseudohyphae.

Harmful 1. Molds can cause deterioration of fabrics, leather, electrical insulation and other manufactured goods. Extensive losses may follow failure to protect material from ravages of fungi in warm humid climates.

2. Fungi can spoil the agricultural produce, if improperly stored. These also destroy vegetables, fruits and cereals.

3. Mycotoxicoses (ingestion of toxins of fungal origin) and mycetismus (mushroom poisoning— through ingestion of fungal elements) are becoming increasingly a public health problem in tropical countries such as India.

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Unit 3: Check for facts and Understanding Multiple choices: Write the letter of your choice in your answer beside the number.

1.

Which among the following bacteria can live without an oxygen environment?

A. Aerobic bacteria B. Anaerobic bacteria C. Cocci bacteria D. Staphylococcus

2.

Genetic information of a virus is contained in which of the following ?

A. The envelope B. Central nucleic acid C. The prion D. The viroid

3.

The envelope of a virus is made of which of the following?

A. Piece of the capsid B. Piece of host cell’s membrane C. Piece of nuclei of the virus D. Piece of the nuclei of the host cell

4.

A. B. C. D.

What is capsid?

A capsid is the protein coat that encapsulates a virus A capsid is the membrane bilayer of a virus A capsid is the another name for a bacteria A capsid is the envelope around a virus

A. B. C. D.

What is a small infectious particle that contains a protein?

Viroid Capsid Virion Prion

5.

6.

7.

Which among the following is called as naked virus?

A. A virus without an envelope B. A virus without a capsid C. A virus without RNA D. A virus without DNA Fungi are different from plants because?

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8.

9.

D. Plants absorb nutrients from organic wastes The body of a mold or fleshy fungus is made up of long, loosely packed filaments called?

A. Soma B. Hyphae C. Thallus D. Mycelium What can be produced by Fungi Imperfecti?

A. Sexually B. Do not reproduce C. Asexually D. Both A and B

10.

A. B. C. D.

What category can mushrooms include?

Fungi Protozoa Helminths Algae

11.

Rod-shaped bacteria with flagella at both ends of the rod, which give the bacteria mobility are called?

A. Pseudomonas auruginosa B. Legionella pneumophilia C. Pseudomonas D. Legionella Micdadei 12.

What you called the Aerobic bacteria is designed for bacteria that require a small amount of oxygen.

A. True B. False C. Neither A and B D. Both A and B 13.

All of the following are the shapes of bacteria. Which among the shapes is not included?

Round Spiral Spheroidal Oblong 14.

What kind of microorganisms are too small that cannot be visualized by the human normal eye?

A. B. C. D.

A. B. C. D.

Bacteria Dust Air Water

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15.

What part of bacteria are used for mobility?

A. B. C. D.

Cytoplasm Flagella Ribosome Capsule

A. B. C. D.

How fast is the average time for bacteria to multiply?

5-10 sec 10-20 min 30-60 sec 20-20 min

16.

17.

What bacteria is the most common cause of food poisoning?

A. B. C. D.

18.

What phase of bacterial growth has a shortest duration?

A. B. C. D.

19.

Mycobacterium leprae Salmonella enteritidis Clostridium Staphylococcus

Lag phase Log phase Stationary phase Decline phase

What is the other name for the Exponential phase?

A. Lag phase B. Log phase C. Stationary phase D. Decline phase

20.

Others called it the death phase because of the depletion of nutrients and accumulation of toxic end products, the number of bacteria dying.

A. B. C. D.

Lag phase Log phase Stationary phase Decline phase

References : Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

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LABORATORY ACTIVITY 3 SPECIMEN COLLECTION

Name:_______________________________________________Score:____________ Date Performed :_________________________

Datesubmitted:___________________

Section:___________

I. OBJECTIVE The students are expected to describe the different methods of specimen collection, the importance of proper specimen collection and the application of sterile techniques at all times

II. DISCUSSION Nurses are instrumental in the collection of specimens because they are always in contact with the patients. Proper knowledge and skill is necessary in order not to have false positive results or endanger both the patients and the nurse. It is critical that the specimen collected and transported are of quality when submitted to the laboratory.“Garbage in, garbage out” is an adage that describes the importance of quality when it comes to specimen collection and transport. Meaning, whatever sample given for study, that same sample is what will be identified including its contaminants. Specimens should be obtained to preclude the possibility of contamination that is not involved in the infectious process. Ideally, specimens would be transported within 30 minutes from collection. All specimen containers should be sterile and leak-proof. Swab specimens are placed in transport media to prevent desiccation of the sample. Aseptic practice, therefore, is necessary to prevent contamination of the specimen,infection of the health care provider, and cross contamination between patients.

5 5 POINTS FOR EACH 4 ILLUSTRATION 3 QUESTION 2 1 0 2 POINTS IS GIVEN 2 FOR EVERY TERM 1 CORRECTLY 0 DEFINED IN RESEARCH

OUTSTANDING; No mistakes identified EXCELLENT; 2 mistakes or missing concepts identified GOOD; 3 mistakes or missing concepts identified FAIR; 4 mistakes or missing concepts identified POOR; 5 mistakes or missing concepts is identified The answer is totally different from the expected response All concepts are defined A concept is missing The definition is totally different from the expected response

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III. MATERIALS Pencil,Paper, coloring materials Reference materials

IV. PROCEDURES

1. Read the following steps in collecting samples from different sites of the body for microbial investigation

2. Draw an illustration of the collection process.Explain the procedure and why it is important?

A.

NOSE AND THROAT SWABS

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B.

EAR SWAB

C. RECTAL SWAB

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D. VAGINAL SWAB

D.

QUESTIONS FOR RESEARCH

1. Describe the proper collection, transport and storage of the following puncture fluid specimen:

a. Cerebrospinal fluid (CSF)

b. Amniotic fluid

c. synovial fluid

d. Ascitic fluid

2. What are the Universal Precautions for Health-Care professionals in specimen collection?

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Unit IV HOST DEFENSE MECHANISM Immunology has broad biological role involving concept of recognition, specificity and memory.

In this unit of you will be able to understand relevant topics regarding the Host defense mechanism in the field of medicine.

Objectives: After studying this unit, you should able to: 1.

Give example of the various types of acquired and innate immunity 2.

Discuss the national; immunization Program 3.

List down the name of vaccines, dosage, and schedule being distributed by DOH

I. Definition Among the most dangerous enemies to whom human beings act as hosts are the microorganisms of the microorganism can result in the development of disease because of imbalance in host parasite relationships that had previously been innocuous. Host-parasite interaction is a dynamic equilibrium. When host resistance is impaired, organisms that are even normally present may cause disease.

Here are some definitions of terms to be learned in this unit.

Immunology- It is a study of specific resistance to further infection by a particular microorganism to its products.

Parasite- lives on the body of the host or another organism Host- the one who owns the body and the one harming the parasite and possibly causing death.

Host-parasite relationship - lived together which is the other is harming the other Immunity- The resistance offered by the host to the harmful effect of pathogenic microbial infections.

Innate immunity - Natural resistances with which a person is born Specific immunity - Acquired immunity when a person meets antigens after birth Humoral immunity - depends on antibody production against specific antigen by B cells.

Cellular immunity - directly kills foreign cells by the help of helper T cells and T cytotoxic cells.

Antibodies - helps fight off infection and can provide protection against getting those diseases again.

Antigens - substances that cause an immune response in the body in identifying substances and try to eliminate them.

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Immunity is a state of resistance to an infectious agent. It depends on the ability of the body to recognize and dispose of foreign microorganisms and other naturally occurring organic substances, including pollen, dust and cells from other organisms. There are two types of immunity that interact and are necessary for survival. These are innate immunity and adaptive or acquired immunity which is subject to individual variation.

II. INNATE OR NONSPECIFIC IMMUNITY These are non specific parts of immunity and it is the natural resistances with which a person is born. This is basic immunity which may be genetically passed on from one generation to another generation. Innate or natural resistance is an inborn result of the genetic constitution of the individuals. The first line of defense in innate immunity are the combination of physical and chemical barriers that prevent all types of foreign agents from penetrating the outer layer of the body. The external system prevents the entry of microbes into the body and the internal system comes into play following injuries that breach the physical barriers.

Characteristics of components of Natural Resistance First line of defense or The external Defense System - The first line of defense against infection are the external system. Major components of the external system are the mechanical barriers, the effectiveness of which is enhanced by various antimicrobial secretions. External defense system are the following: ✔

The Skin

✔

The respiratory tract

✔

The digestive tract

✔

The mouth

✔

The urogenital tract

✔

The Eye

Body site

Defense Mechanism

Skin

Dryness, acidity, toxicity, constant shedding Ciliated cells, constantly moving mucus to throat

Respiratory tract

Gastrointestinal tract Vagina

Condition entry

that

foster

Wounds, excess moisture, serious discharge Reduced movement of ciliated cells as in smoking, chilling, narcotics, viral infection.

0.2% hydrochloric acids, Reduced stomach acid, enzyme pepsin ingestion of antacids Lactobacilli during childbearing Reduced numbers of years lactobacilli from douching A Self-regulated Learning Module

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Urinary Tract

Flushing action of urination

soaps, menopause, antibiotic therapy.

Short urethra in women, incomplete or infrequent urination, sexual intercourse.

The Phagocytic specific defense or The Internal Defense Systems

Microbes that by one means or another succeed in passing the external barriers encounter the second line of defense. The phagocytic cells are a major factor in this line of defense.If the barrier of the body is overcome by the organisms, a number of factors in normal tissue and body fluid, play their role. The Tissue factors may be divided into: A.

Humoral factors

B.

Cellular Factors

Humoral factors Production of antibodies against antigens of microorganism may be induced resistance because they neutralizes toxin or cellular products, have direct bactericidal or lytic effect with complement,block the ineffective ability of microorganisms, agglutinate microorganisms thus subjecting them to phagocytosis and opsonize microorganisms. Humoral factors includes: a.

Lysozyme - It is a bactericidal enzyme found in nasal and intestinal secretion, seminal fluid and lacrimal secretion.

b.

Properdin - It is euglobulin present in normal serum. It is not an antibody and its level remains constant in newborn and elderly individuals in both sexes.

c.

Beta lysin- It is a relatively thermostable substance active against anthrax bacillus. It is liberated from platelets during clotting.

d.

Basic polypeptides. They are bactericidal substances active at high pH (7-8). They act upon cell wall causing cell disintegration. E.g lukins from leukocytes and plakin from platelets.

e.

C-reactive proteins - These nonspecific substances (C-reactive protein) appear in the blood of a person with tissue necrosis and inflammation. C-reactive protein does play an important role in the resolution of inflammatory processes. It binds to many materials like bacterial polysaccharides and may then activate classical pathways, bringing complement components into play to potentiate bacterial killing.

f.

Bactericidin - It is a non-specific serum factor active against neisseria, streptococcus hemolyticus.

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g.

Complement - It is a thermostable substance present in serum and tissue fluid. It enhances phagocytosis and kills most gram negative bacteria synthesized by specific antibodies.

h.

Non-specific hyaluronidase inhibitors - It is heat labile and requires magnesium ion for its activity.

Cellular factor Cellular factors classified as: a.

Phagocytosis - Natural defence against invasion of blood and tissue by bacteria or other foreign particles is mediated by phagocytic cells which ingest and destroy them.

b.

Inflammatory response - It is a complex series of events that is a part of the response of all multicellular organisms to the introduction into their tissues of living and non-living foreign agents.

There are five cardinal sign of acute inflammation are ✔ redness or erythema ✔ Swelling ✔ Pain ✔ Heat ✔ Loss of function

c.

Fever - It is a natural defence mechanism. It may actually destroy the infecting organism. Fever stimulates the production of interferon and helps in recovery from virus infections. The substances which may cause fever are endotoxins and interleukin-1. ✔ Stimulation of production of a group of substances called colony stimulating factor (CSF) ✔ Induction of acute phase reactants which are a group of plasma proteins that serves as nonspecific host resistance factors and may also function to aid tissue repair.

III. ACQUIRED IMMUNITY Acquired immunity refers to that immunity which a person develops during his lifetime. Acquired immunity is the surveillance mechanism that specifically recognizes foreign antigens and selectively eliminates them, and on re-encountering the antigen has an enhanced response.

Characteristics of acquired immunity ✔

Specificity

✔

Inducibility

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✔

Diversity

✔

Memory

✔

Distinguishing self from nonself

✔

Self-limiting

Two types of Acquired Immunity 1.

Active Acquired Immunity

2.

Passive Acquired Immunity

1.

Active Acquired Immunity - It is the resistance developed by an immunity as a result of antigenic stimulus. A degree of naturally acquired active immunity results from any infection from which a person recovers, whether the illness is serious or subclinical.

A. Natural Active immunity- This is acquired after one infection or recovery from disease or subclinical infection after repeated exposure to small doses of the infecting organism. It develops in response to an infection.

B. Artificial active immunity - It may be acquired artificially by inoculation of bacteria, viruses or their products as under. This antibodies developed in response to a vaccination i.

Living organisms - After proper attenuation e.g smallpox, BCG etc.

ii.

Organisms are killed by heat or phenol without changing the antigenic structure of bacteria e.g typhoid vaccine, cholera vaccine.

iii. Autovaccine iv. Non specific protein therapy- Local cellular elements concerned with defensive mechanisms respond to injection of non-specific protein substances like milk injection. v.

2.

Toxoid - Bacterial inactivated toxin e.g diphtheria and tetanus toxoid.

Passive Immunity

Passive immunity is developed after you receive antibodies from someone or somewhere else. Passive also be acquired by Natural or artificial means.

A. Natural Passive immunity - During intrauterine life transmission of antibodies from the mother to fetus can occur through placenta. It may be by way of colostrum of mother and milk during the first few months of life. Breast-fed infants resist establishment of enteroviruses in the alimentary tract. These antibodies last for a few weeks and protect A Self-regulated Learning Module

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infants from diphtheria, tetanus, measles, mumps, smallpox, etc. This is caused almost entirely by IgG since other immunoglobulins do not pass the placental barrier. Colostrum contains secretory IgA and IgM which are not destroyed by the poorly developed digestive system.

B. Artificial Passive immunity - Artificial passive immunity refers to the original production of antibodies in some other individual (either human or lower mammal) and the acquisition of these antibodies through parenteral route. Injections of hyperimmune serum (against rabies, tetanus, hepatitis, etc.) represent this type of immunization.

Humoral Immunity - Immunity based on antibodies is called as humoral immunity. Antibodies are produced by a B subset of lymphocytes. probably the most formidable type of immunity.

This form of immunity is conveniently subdivided into that which is actively acquired and that which is passively acquired. Key features of adaptive humoral immunity include: ✔

Antigen specificity

✔

Clonal Selection

✔

Clonal Expansion

✔

Clonal Suppression and formation of memory cells

✔

Antibodies

Cell- Mediated Immunity ( CMI) - Cell-mediated immune response is a complex process which is based mainly upon thymus dependent lymphocytes called T cells. Two sub-populations of T cells play an important role in CMI: T helper (TH) cells and T cytotoxic (TC) cells. Cellmediated immunity protects against intracellular microorganisms, such as viruses, and is important in the rejection of organ transplants and tumour cells.

Difference between active and passive immunity ACTIVE IMMUNITY PASSIVE IMMUNITY Produces activelty by host’s immune system Received passively by the host. No participation by host’s immune system Induced by infection or by contacts with Conferred by introduction of vacines e.g immunogen readymade antibody Afford durable and effective protein Temporary and less effective protection Immunological memory present No immunological memory Negatice phase may occur No negative phase Not applicable to immunodeficient hosts Application to immunodeficient hosts Used as prophylaxis to increase resistance of Used for treatment of acute infection body Both cell mediated and humoral immunity Exclusively humoral immunity is involved.

No inheritance of immunity May be acquired from Mother

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IV. FAILURE OF IMMUNE RESPONSE The specific reactivity induced in hosts by antigenic stimulus is called the immune response may be beneficial, harmful or non-reactive (tolerance). There are two responses of our body to the pathogens.

1.

Primary Response

2.

Secondary Response

1.

Primary Response - initial antigenic stimulus is slow, sluggish, short lived with a long lag phase and low antibody titer that does not persist for a long time. Antibodies formed are predominantly IgM.

Primary immune response an antigenic stimulus. (1) Latent period, (2) Rise in titer of serum antibody, (3) Steady state of antibody titer, and (4) Decline of antibody titer Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

2.

Secondary Response - Secondary response to subsequent stimuli, is prompt, powerful prolonged, and with much higher levels of antibody. It lasts for a long time. Antibodies predominantly formed are IgG.

Secondary immune response. Effect of repeated antigenic Secondary

stimuli

A,B,C:

(1)

immune response, (2) Negative immune response, (3) Negative phase, (4) High level of antibody after booster dose

Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

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FACTORS INFLUENCING ANTIBODY PRODUCTION 1.

Age: Embryo is immunologically immature, immunocompetence is not complete at

birth. The infant has to depend on maternal antibodies from 3 to 6 month of age. By this time maternal antibodies disappear. Full competence is acquired only by the age of 4years. In old age capacity to produce antibodies is reduced.

2.

Nutritional status: Protein calorie malnutrition suppresses both humoral as well as cellular immune response. Deficiency of amino acids and vitamins causes decrease in antibody synthesis.

3.

Route of administration: The human immune response is better following parenteral administration of antigen than oral or nasal routes. However, for production of IgA antibody, oral or nasal route is suitable

4.

Size and number of doses: An antigen is effective only above critical dose. Further increase in dose enhances antibody production. The massive antigen stimulus appears to inhibit antigen antibody systems. This is called immunological paralysis.

5.

Multiple antigens - When two or more antigens are administered.

6.

Adjuvant - The term adjuvant refers to any substance that enhances immunogenicity of an antigen. The most potent adjuvant is Freund’s complete adjuvant which is the combination of incomplete adjuvant along with suspension of killed tubercle bacilli. It is not used in human beings. Beside increasing humoral immune response it induces high degree of cellular immunity. The adjuvant commonly used in human vaccine are aluminium hydroxide, phosphate, endotoxin and mineral oils.

7.

Immunosuppressive agent: X-rays and cortisone if administered before antigenic stimulus, suppress antibody formation. They do not change antibody levels if administered after antibody formation.

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Immune response Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

ANTIBODY The production of antibodies is a part of the response of the immune system to antigenic stimulation. Antibodies are blood proteins, all of which are globulins (hence the synonymous immunoglobulins) part of the gamma fraction of serum. In addition to those found in blood (humoral antibodies), some types of antibodies are fixed to body cells or tissues or exist in body secretions (cell bound antibodies).

Characteristics of Immunoglobulins

1.

Immunoglobulin G (IgG) is the class of immunoglobulin which has maximum concentration in serum and is the major immunoglobulin to be synthesized during the secondary immune response. It is the major line of defence in a newborn because of its capability to pass through placenta as well as to be secreted in colostrum. IgG can be further subgrouped into four isotypic subclasses - IgG1, IgG2, IgG3, and IgG4.

2.

Immunoglobulin A ( IgA) - is to defend the exposed external surfaces of the body against attack by microorganisms. It appears selectively in saliva, tears, nasal fluid, sweat, colostrum and secretions of lungs, genitourinary and gastrointestinal tracts. IgA is synthesized locally by plasma cells. It prevents the entry of microbes into body tissues. Aggregated IgA binds to polymorph, and also activates the alternative pathway of complement.

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3.

Immunoglobulin M (IgM) - Because of high molecular weight (900,000) and a polymer of five four peptide units, the IgM is also referred to as the macroglobulin antibody. These antibodies are extremely efficient, appear early in response to infection and are largely confined to the bloodstream.

4.

Immunoglobulin D (IgD) - IgD is present on the surface of a proportion of blood lymphocytes where it seems likely that they may operate as mutually interacting antigen receptors for the control of lymphocyte activation and suppression.

5.

Immunoglobulin E (IgE) - Very few plasma cells in body synthesize this immunoglobulin and the concentration of IgE in serum is also very low. IgE antibodies remain firmly fixed for an extended period when injected into human skin where they are probably bound to mast cells.

Contact with antigen leads to release of vasoactive amines. The main physiological role of IgE seems to be protection of external mucosal surfaces of the body through triggering an acute inflammatory reaction

Biological properties of immunoglobulins Source: R. Bhatia, R.Ichhpujani.,Essentials of Medical Microbiology

V. APPLICATIONS OF IMMUNOLOGY Application of immunology is the ability to detect and fight off infection, Ability to recognize a host’s own cells as “Self”, thereby protecting them from attack. A memory from previous foreign infections and the ability to limit the response after the pathogen has been removed.

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A.

Serological Test

These tests detect antibodies to extracellular products liberated by strep. Pyogenes.

These are preferably performed on paired serum samples to detect rise in antibody titre to one or other products. These tests can be used to confirm the presumed bacteriological diagnosis as well as for the diagnosis of post streptococcal sequelae where isolation of streptococci or detection of their antigens is not possible.

B.

Immunoprophylaxis

Vaccines It is worthwhile to discuss the history of vaccine development. Along with it other aspects are also taken up

History of Development of Immunization 1721 Variolation by Lady Montague 1793 Smallpox immunization 1881 Development of Pasteur’s antirabies vaccine and also demonstration of efficacy of anthrax vaccine 1891 Development of diphtheria antitoxin 1896 Vaccine against typhoid fever 1904 Production of tetanus antitoxin 1920 Diphtheria antitoxin floccules 1930 Diphtheria toxoid 1951 Yellow fever live vaccine 1955 Polio killed vaccine (SALK) 1960 Polio live vaccine (SABIN) 1970 Live vaccine of rubella and mumps. Also measles vaccine (killed as well as live)

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Vaccines are preparation of antigenic materials, which are administered with the object of inducing in the recipient specific and active immunity against infectious microorganisms or toxins produced.

TYPES OF VACCINES 1.

Active Immunization A. Live attenuated vaccines are smallpox, yellow fever, polio, BCG, plague, brucellosis, mumps, rubella and measles. Attenuation is achieved by aging of culture, culture at high temperature, passage through another host species, drying (rabies) and selection of mutant (temperature sensitive) B. Inactive or Killed vaccines, e.g. whooping cough, TAB, cholera, polio (SALK), antirabic and measles. For this purpose organisms are killed by heat, formalin, phenol, alcohol, ultraviolet light and photodynamic inactivation. Killed vaccines may be preserved in phenol, alcohol or merthiolate.

C. Toxoids are exotoxin which are treated with formalin to destroy their toxicity but retaining their immunogenicity, e.g. formal toxoid of diphtheria and tetanus.

D. Subunit vaccines: They consist of only relevant immunogenic material such as the capsid proteins of non-enveloped icosahedral viruses or the peplomers (glycoprotein) of enveloped proteins.

ClassClassification of vaccines available against microorganisms VACCINES AGAINST BACTERIA Live attentuated ● Mycobacterium tuberculosis vaccines ● Vibrio cholerae ● Salmonella ● E.coli

Inactiveated vaccine

● ● ● ●

VACCINES AGAINST VIRUSES ● Polio ● Mumps ● Measles ● Rubella ● Vaccinia ● Adeno ● Rabies ● Herpes zoster ● Cytomegalo ● Influenza ● Yellow fever ● Rotavirus Rabies Polio Influenza Hepatitis B Measles

● Plasmodium falciparum ● Trypanosomes cruzi ● Schistosoma

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Corynebacterium diphtheriae Pertussis Clostridium tetani Vibrio cholerae

● ● ● ● ●

VACCINES AGAINST PARASITES

● ● ●

Meningococcus Pneumococcus Haemophilus influenzae E. coli

mansori ●

National Immunization Program ( NIP) A National Immunization Programme ( NIP) is the organizational component of Ministries of Health charged with preventing diseases, disability and death from vaccine-preventable diseases in children and adults. A NIP is a government programme that operates within the framework of overall health policy.

The NIP is used interchangeably with the Expanded Program on Immunization (EPI) that originally focused on preventing vaccine- preventable diseases in children. All countries have a national immunization programme to protect the population against vaccine-preventable diseases.

Department of Health Immunization Schedule Source: https://www.doh.gov.ph/node/6035

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SERA Sera contain antibodies to specific bacteria or viruses. It provides passive immunity to a specific antigen or disease. Sera is also used as a prophylaxis against specific disease after exposure and may lessen the severity of a disease. Antitoxin and Antivenon are examples of immune sera that have antibodies to specific toxins that might be released by invading pathogens or to venom from spider or snake bites.

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Uni t4: Check for Facts and Understanding EVALUATE Answer the following Questions 1.

What are the first level of defense? a. c.

2.

Give atleast 2 second line of defense a) b)

3.

Give the two types of Immunity. a) b)

4.

Give 2 vaccines that need to be given at the first 24 hrs of birth a) b)

EXPLORE 5.

Explain and Give example of the following: a)

Active immunity-

b)

Passive immunity-

c)

Natural active immunity-

d)

Natural Passive immunity-

e)

Artificial active immunity-

f)

Artificial passive immunity-

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LABORATORY ACTIVITY 4 IMMUNOLOGY

I. OBJECTIVE

The students are expected to correctly discuss what body’s defenses against infections are; differentiate innate from acquired immunity; artificial from natural immunity; and to describe the different mechanisms under each category of immunity.

II. DISCUSSION

Immunology is a science that deals with the immune system and the cell-mediated and humoral aspects of immunity and immune response. Our body responds to various microbial invaders in either non-specific or specific ways. Non-specific immunity is our 1st fine of defense and second line of defenses. The first line of defense includes non-specific physical and chemical defenses like the skin. Mucous membranes, stomach acid, lysozyme in tears; they are non-specific natural barriers which restrict entry of pathogens. The second line of defense is innate non-specific immune defenses that provide rapid local response to pathogens after it has entered the host.

Examples are the actions of the phagocytes (macrophages and neutrophils), protective proteins like cytokines, fever, NK cells, interferon, and inflammation. The specific (acquired) immunity is considered as the third line of defense, also known as adaptive immunity. It deals with the production of specific proteins against particular microbes. It is antigen-specific (acquired) immunity that specifically targets and attacks invaders that get past the first two lines of defense. The protective proteins are called antibodies or the immunoglobulins, produced by the B- cells or B Lymphocytes as a response to foreign materials to the body called antigens or the immunogens.

III. MATERIAL Pencil, Paper, drawing materials, Reference materials RUBRICS 5 POINTS FOR EACH 5 ILLUSTRATION QUESTION 4

OUTSTANDING; No mistakes identified

EXCELLENT; 2 mistakes or missing concepts identified

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3

GOOD; 3 mistakes or missing concepts identified

2

FAIR; 4 mistakes or missing concepts identified

1

POOR; 5 mistakes or missing concepts is identified

0

The answer is totally different from the expected response

2 POINTS IS GIVEN 2 FOR EVERY TERM CORRECTLY DEFINED 1 IN RESEARCH 0

All concepts are defined

A concept is missing

The definition is totally different from the expected response

IV. PROCEDURE A.

Draw and Label the following 1.

Typical antibody structure

2.

A dimmer ( Immunoglobulin A)

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3.

A pentamer ( Immunoglobulin M)

4.

A neutrophil

5.

Eosinophil

6.

Basophil

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7.

Phases of Phagocytosis

V. Question for Research 1.

Fill up the table regarding the different types of leukocytes

Type

Normal value (%) in peripheral blood

Functions

A. Granulocytes (polymorphonuclear leukocytes)- 5,000-10,000/mm 1.

Neutrophils 2.

Basophils 3.

Eosinophils B. Agranulocytes (produced in lymphatic system; non-granular under microscope) 1.

2.

Monocytes Lymph Nodes

2. Different antibodies ( Immunoglobulins- GAMED) Criteria Form Molecular weight Description % in total Ig

IgG

IgA

IgM

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IgD

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Concentration in serum Number of antigenic binding sites Function/s

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UNIT V MICROBIAL INFECTION Microbial infection occurs when a microorganism enters a person's body and causes harm or diseases. These microorganisms are the viruses, bacteria, protozoa, and fungi. In this unit we can understand the effects of these microorganisms once it enters our body ( Respiratory, Gastrointestinal, urinary, central nervous , Blood and skin and eyes.

Objectives After Studying this unit, you should be able to: 1. Identify agents and vectors involved in the spread of infectious diseases.

2. Describe different modes of transmission of infectious diseases.

3. Discuss prevention and treatments of infectious diseases.

4. Understand clearly the different types of communicable disease that affects the different systems of the body.

5. Understand the importance of good personal hygiene in the prevention and control of infection.

Anatomy of the respiratory system Figure 1

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Figure 2

Source:healthengine.com

BACTERIA I. INFECTION OF THE RESPIRATORY SYSTEM

1. Diphtheria Diphtheria (dif-THEER-e-uh) is a serious bacterial infection usually affecting the mucous membranes of your nose and throat. Diphtheria typically causes a sore throat, fever, swollen glands and weakness. But the hallmark sign is a sheet of thick, gray material covering the back of your throat, which can block your airway, causing you to struggle for breath.

Incubation period – is usually 2–5 days (range: 1–10 days).

Causative agent - Corynebacterium diphtheria

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Figure 3

Source: Cdbioscience.com

Figure 4

Source:Microbewiki.com

Mode of Transmission : Diphtheria spreads (transmits) from person to person, usually through respiratory droplets, like from coughing or sneezing. Rarely, people can get sick from touching open sores (skin lesions) or clothes that touch the open sores of someone sick with diphtheria. A person also can get diphtheria by coming in contact with an object, like a toy, that has the bacteria that cause diphtheria on it.

Vaccination : Diphtheria toxoid combined with tetanus and pertussis vaccines (DTP).

Symptoms : Diphtheria signs and symptoms usually begin two to five days after a person becomes infected and may include: a. A thick, gray membrane covering your throat and tonsils b. A sore throat and hoarseness A Self-regulated Learning Module

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c. d. e. f. g.

Swollen glands (enlarged lymph nodes) in your neck Difficulty breathing or rapid breathing Nasal discharge Fever and chills Malaise

Skin (cutaneous) diphtheria : A second type of diphtheria can affect the skin, causing the typical pain, redness and swelling associated with other bacterial skin infections. Ulcers covered by a gray membrane also may develop in cutaneous diphtheria.

Causes : The bacterium Corynebacterium diphtheriae causes diphtheria. Usually C. diphtheriae multiplies on or near the surface of the mucous membranes of the throat. C. diphtheriae spreads via three routes:Airborne droplets. When an infected person's sneeze or cough releases a mist of contaminated droplets, people nearby may inhale C. diphtheriae. Diphtheria spreads efficiently this way, particularly in crowded conditions. Contaminated personal items. People occasionally catch diphtheria from handling an infected person's used tissues, drinking from the infected person's unwashed glass or coming into similarly close contact with other items on which bacteria-laden secretions may be deposited. Contaminated household items. In rare cases, diphtheria spreads on shared household items, such as towels or toys.

Figure 5

Source: Slideshare.net

Diagnostic / laboratory test : Bacteriologic culturing is essential to confirm the diagnosis of diphtheria. In all patients in whom diphtheria is suspected and in their close contacts, obtain specimens from the nose and throat (ie, nasopharyngeal and pharyngeal swab) for culture.

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Risk factors : People who are at increased risk of contracting diphtheria include: a. Children and adults who don't have up-to-date immunizations b. People living in crowded or unsanitary conditions c. Anyone who travels to an area where diphtheria is endemic Complications : Left untreated, diphtheria can lead to: a. Breathing problems. Diphtheria-causing bacteria may produce a toxin. This toxin damages tissue in the immediate area of infection — usually, the nose and throat. At that site, the infection produces a tough, gray-colored membrane composed of dead cells, bacteria and other substances. This membrane can obstruct breathing. b. Heart damage. The diphtheria toxin may spread through your bloodstream and damage other tissues in your body, such as your heart muscle, causing such complications as inflammation of the heart muscle (myocarditis). Heart damage from myocarditis may be slight, showing up as minor abnormalities on an electrocardiogram, or severe, leading to congestive heart failure and sudden death. c. Nerve damage. The toxin can also cause nerve damage. Typical targets are nerves to the throat, where poor nerve conduction may cause difficulty swallowing. Nerves to the arms and legs also may become inflamed, causing muscle weakness. If C. diphtheria toxin damages the nerves that help control muscles used in breathing, these muscles may become paralyzed. Respiration may then become impossible without a respirator or another device to assist with breathing

Treatment : a. An antitoxin. If doctors suspect diphtheria, the infected child or adult receives an antitoxin. The antitoxin, injected into a vein or muscle, neutralizes the diphtheria toxin already circulating in the body.

Before giving an antitoxin, doctors may perform skin allergy tests to make sure that the infected person doesn't have an allergy to the antitoxin. People who are allergic must first be desensitized to the antitoxin. Doctors accomplish this by initially giving small doses of the antitoxin and then gradually increasing the dosage. b. Antibiotics. Diphtheria is also treated with antibiotics, such as penicillin or erythromycin. Antibiotics help kill bacteria in the body, clearing up infections.

Antibiotics reduce to just a few days the length of time that a person with diphtheria is contagious.

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2. Streptococcal sore throat It is a bacterial infection that can make your throat feel sore and scratchy. Strep throat accounts for only a small portion of sore throats.

Figure : 6

Source:healthline.com

Causative agent Streptococcus pyogenes, which are also called group A Streptococcus or group A strep,cause acute pharyngitis known as strep throat.

Figure 7

Source: microbewiki.com

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Incubation period : Group A strep pharyngitis is approximately 2 to 5 days.

Mode of transmission: Group A strep pharyngitis is most commonly spread through direct person-to-person transmission. Typically transmission occurs through saliva or nasal secretions from an infected person. People with group A strep pharyngitis are much more likely to transmit the bacteria to others than asymptomatic pharyngeal carriers. Crowded conditions — such as those in schools, daycare centers, or military training facilities — facilitate transmission. Although rare, spread of group A strep infections may also occur via food. Foodborne outbreaks of pharyngitis have occurred due to improper food handling. Fomites, such as household items like plates or toys, are very unlikely to spread these bacteria.

Humans are the primary reservoir for group A strep. There is no evidence to indicate that pets can transmit the bacteria to humans.

Vaccination: No vaccine Diagnosis: Your doctor will conduct a physical exam, look for signs and symptoms of strep throat, and probably order one or more of the following tests: a. Rapid antigen test : rapid antigen test on a swab sample from your throat. This test can detect strep bacteria in minutes by looking for substances (antigens) in the throat. If the test is negative but your doctor still suspects strep, he or she might do a throat culture. b. Throat culture. A sterile swab is rubbed over the back of the throat and tonsils to get a sample of the secretions. It's not painful, but it may cause gagging. The sample is then cultured in a laboratory for the presence of bacteria, but results can take as long as two days Signs and symptoms : a. Throat pain that usually comes on quickly b. Painful swallowing c. Red and swollen tonsils, sometimes with white patches or streaks of pus d. Tiny red spots on the area at the back of the roof of the mouth (soft or hard palate) e. Swollen, tender lymph nodes in your neck f. Fever g. Headache h. Rash i. Nausea or vomiting, especially in younger children j. Body aches If untreated, strep throat can cause complications, such as kidney inflammation or rheumatic fever. Rheumatic fever can lead to painful and inflamed joints, a specific type of rash, or heart valve damage.

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a. Scarlet fever, a streptococcal infection characterized by a prominent rash b. Inflammation of the kidney (post streptococcal glomerulonephritis) c. Rheumatic fever, a serious inflammatory condition that can affect the heart, joints, nervous system and skin d. Post streptococcal reactive arthritis, a condition that causes inflammation of the joints Treatment : Medications are available to cure strep throat, relieve its symptoms, and prevent its complications and spread. a. Antibiotics If taken within 48 hours of the onset of the illness, antibiotics reduce the duration and severity of symptoms, as well as the risk of complications and the likelihood that infection will spread to others. penicillin or amoxicillin (Amoxil) to treat strep throat. They are the top choices because they're safer, inexpensive, and they work well on strep bacteria.]

3. Pneumonia

Figure: 8

source: healthengine.com

Infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or pus (purulent material), causing cough with phlegm or pus, fever, chills, and difficulty breathing. A variety of organisms, including bacteria, viruses and fungi, can cause pneumonia.

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Pneumonia can range in seriousness from mild to life-threatening. It is most serious for infants and young children, people older than age 65, and people with health problems or weakened immune systems.

Incubation period : Streptococcus pneumonia 1-3 days. Mycoplasma Pneumonia 2-10 days. Klebsiella Pneumonia 1-3 day. Influenza virus 18 to 72 hours.

Causative agent : a. Bacteria-like organisms. Mycoplasma pneumoniae also can cause pneumonia. It typically produces milder symptoms than do other types of pneumonia. Walking pneumonia is an informal name given to this type of pneumonia, which typically isn't severe enough to require bed rest. b. Fungi. This type of pneumonia is most common in people with chronic health problems or weakened immune systems, and in people who have inhaled large doses of the organisms. The fungi that cause it can be found in soil or bird droppings and vary depending upon geographic location. c. Viruses. Some of the viruses that cause colds and the flu can cause pneumonia.

Viruses are the most common cause of pneumonia in children younger than 5 years.

Viral pneumonia is usually mild. But in some cases it can become very serious.

Figure: 9

Mycoplasma pneumonia Figure 10

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Souce: cbbioscience.com

Mode of Transmission : M. pneumoniae spread from person to person. People without symptoms may carry the bacteria in their nose or throat at one time or another. People spread M. pneumoniae by coughing or sneezing, which creates small respiratory droplets in the air that contain the bacteria. Other people then breathe in the bacteria.

Vaccination : Pneumonia vaccine. Make sure children get vaccinated. Doctors recommend a different pneumonia vaccine for children younger than age 2 and for children ages 2 to 5 years who are at particular risk of pneumococcal disease. Children who attend a group child care center should also get the vaccine. Doctors also recommend flu shots for children older than 6 months.

Signs and symptoms: A. Chest pain when you breathe or cough B. Confusion or changes in mental awareness (in adults age 65 and older) C. Cough, which may produce phlegm D. Fatigue E. Fever, sweating and shaking chills F. Lower than normal body temperature (in adults older than age 65 and people with weak immune systems) G. Nausea, vomiting or diarrhea H. Shortness of breath Complications : A. Bacteria in the bloodstream (bacteremia). Bacteria that enter the bloodstream from your lungs can spread the infection to other organs, potentially causing organ failure.

B. Difficulty breathing. If your pneumonia is severe or you have chronic underlying lung diseases, you may have trouble breathing in enough oxygen. You may need to be hospitalized and use a breathing machine (ventilator) while your lung heals.

C. Fluid accumulation around the lungs (pleural effusion). Pneumonia may cause fluid to build up in the thin space between layers of tissue that line the lungs and chest cavity

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(pleura). If the fluid becomes infected, you may need to have it drained through a chest tube or removed with surgery.

D. Lung abscess. An abscess occurs if pus forms in a cavity in the lung. An abscess is usually treated with antibiotics. Sometimes, surgery or drainage with a long needle or tube placed into the abscess is needed to remove the pus.

Diagnosis : A. Blood tests. Blood tests are used to confirm an infection and to try to identify the type of organism causing the infection. However, precise identification isn't always possible.

B. Chest X-ray. This helps your doctor diagnose pneumonia and determine the extent and location of the infection. However, it can't tell your doctor what kind of germ is causing the pneumonia.

C. Pulse oximetry. This measures the oxygen level in your blood. Pneumonia can prevent your lungs from moving enough oxygen into your bloodstream.

D. Sputum test. A sample of fluid from your lungs (sputum) is taken after a deep cough and analyzed to help pinpoint the cause of the infection. *Additional tests if you're older than age 65, are in the hospital, or have serious symptoms or health conditions. These may include: a. CT scan. If your pneumonia isn't clearing as quickly as expected, your doctor may recommend a chest CT scan to obtain a more detailed image of your lungs. b. Pleural fluid culture. A fluid sample is taken by putting a needle between your ribs from the pleural area and analyzed to help determine the type of infection.

Treatment : Specific treatments depend on the type and severity of your pneumonia, your age and your overall health. The options include: a. Antibiotics. These medicines are used to treat bacterial pneumonia. It may take time to identify the type of bacteria causing your pneumonia and to choose the best antibiotic to treat it. If your symptoms don't improve, your doctor may recommend a different antibiotic. b. Cough medicine. This medicine may be used to calm your cough so that you can rest.

Because coughing helps loosen and move fluid from your lungs, it's a good idea not to eliminate your cough completely. In addition, you should know that very few studies have looked at whether over-the-counter cough medicines lessen coughing caused by pneumonia. If you want to try a cough suppressant, use the lowest dose that helps you rest. c. Fever reducers/pain relievers. You may take these as needed for fever and discomfort.

These include drugs such as aspirin, ibuprofen (Advil, Motrin IB, others) and acetaminophen (Tylenol, others).

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Prevention : To help prevent pneumonia: a. Get vaccinated. Practice good hygiene. To protect yourself against respiratory infections that sometimes lead to pneumonia, wash your hands regularly or use an alcohol-based hand sanitizer. b. Don't smoke. Smoking damages your lungs' natural defenses against respiratory infections. c. Keep your immune system strong. Get enough sleep, exercise regularly and eat a healthy diet.

4. Tuberculosis Or TB, as it’s commonly called -- is a contagious infection that usually attacks the lungs. It can also spread to other parts of the body, like the brain and spine.

Causative agent : Mycobacterium tuberculosis

Figure 11

Incubation period : varies from weeks to years, depending on the individual and whether the infection is primary, progressive, or reactivation TB

Mode of transmission : Airborne droplets during sneezing, coughing, and contact with disease by close contact with infected people

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Vaccination : Bacille Calmette-Guerin vaccine or BCG vaccine

Two types of Tuberculosis a. Latent TB : In this condition, you have a TB infection, but the bacteria remain in your body in an inactive state and cause no symptoms. Latent TB, also called inactive TB or TB infection, isn't contagious. It can turn into active TB, so treatment is important for the person with latent TB and to help control the spread of TB. An estimated 2 billion people have latent TB. b. Active TB : This condition makes you sick and in most cases can spread to others. It can occur in the first few weeks after infection with the TB bacteria, or it might occur years later.

Signs and symptoms : a. b. c. d. e. f. g. h. i.

Coughing that lasts three or more weeks Coughing up blood Chest pain, or pain with breathing or coughing Unintentional weight loss Fatigue Fever Night sweats Chills Loss of appetite

Laboratory test : There are two kinds of tests that are used to detect TB bacteria in the body: a. TB skin test (TST) and TB blood tests A positive TB skin test or TB blood test only tells that a person has been infected with TB bacteria. It does not tell whether the person has latent TB infection (LTBI) or has progressed to TB disease. Other tests, such as a chest x-ray and a sample of sputum, are needed to see whether the person has TB disease. b. Sputum tests If your chest X-ray shows signs of tuberculosis, your doctor may take samples of your sputum — the mucus that comes up when you cough. The samples are tested for TB bacteria.

- Sputum samples can also be used to test for drug-resistant strains of TB. This helps your doctor choose the medications that are most likely to work. These tests can take four to eight weeks to be completed.

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Treatment : The most common medications used to treat tuberculosis include: a. b. c. d.

Isoniazid Rifampin (Rifadin, Rimactane) Ethambutol (Myambutol) Pyrazinamide

If you have drug-resistant TB, a combination of antibiotics called fluoroquinolones and injectable medications, such as amikacin or capreomycin (Capastat), are generally used for 20 to 30 months. Some types of TB are developing resistance to these medications as well.

Some drugs may be used as add-on therapy to the current drug-resistant combination treatment, including: a. Bedaquiline (Sirturo) b. Linezolid (Zyvox)

5. Pertussis Is a highly contagious respiratory tract infection. In many people, it's marked by a severe hacking cough followed by a high-pitched intake of breath that sounds like "whoop.“ These bacteria attach to the cilia (tiny, hair-like extensions) that line part of the upper respiratory system. The bacteria release toxins (poisons), which damage the cilia and cause airways to swell.

Causative agent: a. Bordetella pertussis is a Gram-negative, aerobic, pathogenic, encapsulated coccobacillus of the genus Bordetella, and the causative agent of pertussis or whooping cough. Like B. bronchiseptica, B. pertussis is motile and expresses a flagellum-like structure.

Figure 12

Source: microbewiki.com

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Incubation period : Commonly 7 to 10 days, with a range of 4–21 days Mode of transmission : Usually spread the disease to another person by coughing or sneezing Vaccination : DPT vaccine Diagnosis : a. Nose or throat culture and test. Your doctor takes a swab or suction sample from the area where the nose and throat meet (nasopharynx). The sample is then checked for evidence of the presence of whooping cough bacteria. b. Blood tests. A blood sample may be drawn and sent to a lab to check your white blood cell count, because white blood cells help the body fight infections, such as whooping cough. A high white blood cell count typically indicates the presence of infection or inflammation. This is a general test and not specific for whooping cough. c. Chest X-ray. Your doctor may order an X-ray to check for the presence of inflammation or fluid in the lungs, which can occur when pneumonia complicates whooping cough and other respiratory infections.

Symptoms : Once you become infected with whooping cough, it takes about seven to 10 days for signs and symptoms to appear, though it can sometimes take longer. They're usually mild at first and resemble those of a common cold: a. b. c. d. e.

Runny nose Nasal congestion Red, watery eyes Fever Cough

After a week or two, signs and symptoms worsen. Thick mucus accumulates inside your airways, causing uncontrollable coughing. Severe and prolonged coughing attacks may: a. b. c. d.

Provoke vomiting Result in a red or blue face Cause extreme fatigue End with a high-pitched "whoop" sound during the next breath of air

Treatment : Bacterial infection a.

Antibiotics, usually erythromycin or a family of antibiotics like erythromycin.

Erythromycin is taken for 2 weeks. If antibiotics are recommended, they should take all the doses and finish the recommended course

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a. b. c. d.

Azithromycin* Clarithromycin Erythromycin Trimethoprim-sulfamethoxasole

6. Legionellosis Is an acute bacterial pneumonia with rapid onset of anorexia, malaise, myalgia, headache and rapidly rising fever, progressing to pneumonia, which may lead to respiratory failure and death.

Pontiac fever is an influenza-like illness with spontaneous recovery after 2–5 days. It is a severe form of pneumonia — lung inflammation usually caused by infection.

Causative agent: Various species of Legionella bacteria, frequently Legionella pneumophila, serogroup I.

Figure 13

Source: cdbioscience.com

Mode of transmission: Infection results from inhalation of contaminated water sprays or mists. The bacteria live in water and colonize hot-water systems at temperatures of 20–50 °C (optimal 35–46 °C). They contaminate air-conditioning cooling towers, hot-water systems, humidifiers, whirlpool spas and other water containing devices. There is no direct person-to-person transmission Vaccination:no vaccine Diagnosis / laboratory test : a. Blood tests b. Chest X-ray, which doesn't confirm legionnaires' disease but can show the extent of infection in your lungs A Self-regulated Learning Module

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c. Tests on a sample of your sputum or lung tissue d. CT scan of your brain or a spinal tap (lumbar puncture) if you have neurological symptoms such as confusion or trouble concentrating Treatment: a. Fluoroquinolones and macrolides. Treatment may be necessary for up to 3 weeks.

VIRAL

1. Common Colds It is a viral infection of your nose and throat (upper respiratory tract).

Causative agent : The common cold can be caused by more than 200 different viruses. Around 50 percent of colds are caused by rhinoviruses, other cold-causing viruses include: a. b. c. d. e.

Human parainfluenza virus Human metapneumovirus Coronaviruses adenovirus Human respiratory syncytial virus Enteroviruses

Incubation Period : 1 to 3 days.

Mode of Transmission: a. Spread by germs from coughs and sneezes which can live on hands and surfaces for 24 hours. b. Air droplets from coughs and sneezes and by touching infected surfaces Vaccination: flu vaccine Symptoms and symptoms : Symptoms of a common cold usually appear one to three days after exposure to a cold-causing virus. Signs and symptoms, which can vary from person to person, might include: a. b. c. d. e. f. g.

Runny or stuffy nose Sore throat Cough Congestion Slight body aches or a mild headache Sneezing Low-grade fever A Self-regulated Learning Module

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h. Generally feeling unwell (malaise) Treatment : Although there is no real way of treating or curing a common cold, the following measures may help ease the symptoms: a. Drink plenty of fluids and keep well hydrated, being dehydrated when infected with a cold can make symptoms worse. b. Get plenty of bed rest; it is important to get as much sleep/rest as possible while the immune system is fighting off the virus. c. Take aspirin, acetaminophen, or ibuprofen to relieve headache or fever. Do not give aspirin to children under 16. d. Some people find that inhaling steam helps ease the symptoms of nasal congestion.

2. Influenza Viral infection that attacks your respiratory system — your nose, throat and lungs. Influenza is commonly called the flu.

Causative Agent: There are three different types of flu viruses: influenza A, B, and C

Figure 14

Source: cdc.gov

Incubation period : is usually between one and four days.

Mode of Transmission : A droplets when someone with the infection coughs, sneezes or talks. You can inhale the droplets directly, or you can pick up the germs from an object — such as a telephone or computer keyboard — and then transfer them to your eyes, nose or mouth.

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Vaccination : flu vaccine each year.

Symptoms : Flu can cause mild to severe illness, and at times can lead to death. Flu is different from a cold.

Flu usually comes on suddenly. People who have flu often feel some or all of these symptoms: a. b. c. d. e. f. g. h. i.

fever cough sore throat runny or stuffy nose body aches headache chills fatigue sometimes diarrhea and vomiting

*It’s important to note that not everyone with the flu will have a fever.

Treatment : a. Antivirals, such as oseltamivir (Tamiflu) and zanamivir (Relenza), in some circumstances. b. pain relievers can alleviate some of the symptoms, such as a headache and body pains.

Home remedies Individuals with flu should: a. b. c. d. e. f. g.

stay at home avoid contact with other people where possible keep warm and rest consume plenty of liquids avoid alcohol stop smoking eat if possible

3. Hantavirus pulmonary syndrome Is an infectious disease characterized by flu-like symptoms that can progress rapidly to potentially life-threatening breathing problems.

Causative agent: Hantaviruses

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Figure 15

Source: Cdbioscience.com

Incubation period: ranges from 1-4 weeks.

Mode of Transmission: Carried by several types of rodents, particularly the deer mouse. You become infected primarily by breathing air infected with hantaviruses that are shed in rodent urine and droppings. * Inhalation: Main route of transmission Vaccination: no vaccine Symptoms: Hantavirus pulmonary syndrome advances through two distinct stages. In the first stage, you may experience flu-like signs and symptoms that may include: a. b. c. d.

Fever and chills Headaches and muscle aches Vomiting, diarrhea or abdominal pain In its early stages, hantavirus infection is difficult to distinguish from influenza, pneumonia or other viral conditions. After four to 10 days, more-serious signs and symptoms begin. They typically include:

e. f. g. h. i.

A cough that produces secretions Shortness of breath Fluid accumulation within the lungs Low blood pressure Reduced heart efficiency

Prevention : Keeping rodents out of your home and workplace can help reduce your risk of hantavirus infection. Try these tips:

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a. Block access. Mice can squeeze through holes as small as 1/4 inch (6 millimeters) wide.

Seal holes with wire screening, metal flashing or cement. b. Close the food buffet. Wash dishes promptly, clean counters and floors, and store your food — including pet food — in rodent-proof containers. Use tight-fitting lids on garbage cans. c. Reduce nesting material. Clear brush, grass and junk away from the building's foundation. d. Set traps. Spring-loaded traps should be set along baseboards. Exercise caution while using poison-bait traps, as the poison also can harm people and pets.

4.

Severe Acute Respiratory Syndrome ( SARS )Is a contagious and sometimes fatal respiratory illness. A serious form of viral pneumonia.

Causative agent: Coronavirus family of viruses

Figure 16

Source: cdc.gov

Figure 17

Source: Wikipedia.org

Incubation period: usually occurs about 2 to 10 days after coming in contact with the virus.

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Mode of Transmission: Infected droplets spray into the air. You can catch the SARS virus if you breathe in or touch these particles. The SARS virus may live on hands, tissues, and other surfaces for up to 6 hours in these droplets and up to 3 hours after the droplets have dried.

Vaccination:No Vaccine,Experimental vaccines are under development.

Signs and Symptoms: a. Fever b. Headache c. Muscle aches d. Less common symptoms include: e. Cough that produces phlegm (sputum) f. Diarrhea g. Dizziness h. Nausea and vomiting i. Runny nose j. Sore throat k. In some people, the lung symptoms get worse during the second week of illness, even after the fever has stopped.

Exams and Tests: a. Arterial blood tests b. Blood clotting tests c. Blood chemistry tests d. Chest x-ray or chest CT scan e. Complete blood count (CBC) Tests used to quickly identify the virus that causes SARS include: a. Antibody tests for SARS b. Direct isolation of the SARS virus c. Rapid polymerase chain reaction (PCR) test for SARS virus Treatment: People who are thought to have SARS should be checked right away by a provider. If they are suspected of having SARS, they should be kept isolated in the hospital.

Treatment may include: a. Antibiotics to treat bacteria that cause pneumonia (until bacterial pneumonia is ruled out or if there is bacterial pneumonia in addition to SARS) b. Antiviral medicines (although how well they work for SARS is unknown) c. High doses of steroids to reduce swelling in the lungs (it is not known how well they work) d. Oxygen, breathing support (mechanical ventilation), or chest therapy

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In some serious cases, the liquid part of blood from people who have already recovered from SARS has been given as a treatment.

There is no strong evidence that these treatments work well. There is evidence that the antiviral medicine, ribavirin, does not work.

Prevention: Reducing your contact with people who have SARS lowers your risk for the disease. Avoid travel to places where there is an uncontrolled SARS outbreak. When possible, avoid direct contact with people who have SARS until at least 10 days after their fever and other symptoms are gone. a. Hand hygiene is the most important part of SARS prevention. Wash your hands or clean them with an alcohol-based instant hand sanitizer. b. Cover your mouth and nose when you sneeze or cough. Droplets that are released when a person sneezes or coughs are infectious. c. DO NOT share food, drink, or utensils. d. Clean commonly touched surfaces with an EPA-approved disinfectant. e. Masks and goggles may be useful for preventing the spread of the disease. You may use gloves when handling items that may have touched infected droplets.

5. Avian flu a viral respiratory disease Causative agent: Avian influenza Type A viruses

Figure 18

Source: Cdbioscience.com

Incubation period : Averaging 2 to 5 days and ranging up to 17 days Mode of transmission :

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a. Infected birds can shed avian influenza A viruses in their saliva, nasal secretions, and feces. Susceptible birds become infected when they have contact with the virus as it is shed by infected birds. They also can become infected through contact with surfaces that are contaminated with virus from infected birds.

Vaccination : H5N1 Influenza Virus Vaccine Signs and symptoms : a. mild to severe and included conjunctivitis b. influenza-like illness (e.g., fever, cough, sore throat, muscle aches) c. sometimes accompanied by nausea, abdominal pain, diarrhea, and vomiting, severe respiratory illness (e.g., shortness of breath, difficulty breathing, pneumonia, acute respiratory distress, viral pneumonia, respiratory failure) d. neurologic changes (altered mental status, seizures), and the involvement of other organ systems.

Diagnosis / laboratory tests: Avian influenza A virus infection in people cannot be diagnosed by clinical signs and symptoms alone; laboratory testing is needed. Avian influenza A virus infection is usually diagnosed by a. Collecting a swab from the upper respiratory tract (nose or throat) of the sick person.

(Testing is more accurate when the swab is collected during the first few days of illness.)

Treatment: Currently recommends a neuraminidase inhibitor for treatment of human infection with avian influenza A viruses. CDC has posted avian influenza guidance for health care professionals and laboratorians, including guidance on the use of antiviral medications for the treatment of human infections with novel influenza viruses associated with severe disease. Analyses of available avian influenza viruses circulating worldwide suggest that most viruses are susceptible to oseltamivir, peramivir, and zanamivir. However, some evidence of antiviral resistance has been reported in Asian H5N1 and Asian H7N9 viruses isolated from some human cases.

Monitoring for antiviral resistance among avian influenza A viruses is crucial and ongoing.

Prevention: Apart from antiviral treatment, the public health management includes personal protective measures like: a. Regular hand washing with proper drying of the hands b. Good respiratory hygiene – covering mouth and nose when coughing or sneezing, using tissues and disposing of them correctly c. Early self-isolation of those feeling unwell, feverish and having other symptoms of influenza d. Avoiding close contact with sick people e. Avoiding touching one’s eyes, nose or mouth

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f.

Health care workers performing aerosol generating procedures should use airborne precautions. Standard contact and droplet precautions and appropriate personal protective equipment (PPE) should be made available and used during epidemics.

FUNGAL 1. Coccidioidomycosis: Is a pulmonary or hematogenously spread disseminated disease usually occurs as an acute benign asymptomatic or self-limited respiratory infection. The organism occasionally disseminates to cause focal lesions in other tissues. Symptoms, if present, are those of lower respiratory infection or low-grade nonspecific disseminated disease.

Causative agent: Coccidioides immitis , C.posadasii, Incubation period: Averages 10-16 days, with a range of less than 7 days to 30 days.

Mode of transmission : Inhaling fungal spores that are present in the soil. It is not contagious, meaning it cannot be passed from person to person.

Vaccines: no vaccine Signs and symptoms: Many people infected with coccidioidomycosis have no or minimal symptoms. When present, typical symptoms include: a. b. c. d. e. f. g. h.

Cough Chest pain Shortness of breath Fever Joint aches Fatigue Rash A disease that lasts for weeks rather than days

Diagnosis : a. Cultures (routine or fungal) b. Microscopic examination of specimens to check for C. immitis spherules c. Eosinophilia may be an important clue in identifying coccidioidomycosis.

Serologic testing for anti coccidioidal antibodies includes a. Enzyme immunoassay, which is very sensitive and is commonly used to diagnose coccidioidomycosis b. Immunodiffusion kit (to detect IgM or IgG antibodies) c. Complement fixation (to detect IgG antibodies) Treatment: A Self-regulated Learning Module

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a. For mild to moderate disease, fluconazole or itraconazole b. For severe disease, amphotericin B There’s no vaccine. But if you live in or visit a region where valley fever is a possibility, it helps to take common-sense precautions, such as: a. Avoid dusty areas, such as construction sites b. Stay indoors during dust storms, and keep the windows shut c. Avoid activities that put you in contact with dust and soil, such as yard work and gardening d. Filter the air inside your home 2. Histoplasmosis A respiratory disease with symptoms like those of influenza Causative agent: Reproductive cells (spores) of the fungus Histoplasma capsulatum Incubation period:Typically 3–17 days for acute disease. 1-3 weeks after initial infection Mode of transmission:Transmitted when these spores become airborne. breathing in spores of a fungus often found in bird and bat droppings.

Vaccine: no vaccine Symptoms: Several types of histoplasmosis exist. The mildest form produces no signs or symptoms, but severe infections can be life-threatening. When signs and symptoms do occur, they usually appear three to 17 days after exposure and may include: a. Fever b. Chills c. Headache d. Muscle aches e. Dry cough f. Chest discomfort g. In some people, histoplasmosis can also produce joint pain and a rash. People who have an underlying lung disease, such as emphysema, may develop a chronic form of histoplasmosis. h. Signs of chronic histoplasmosis may include weight loss and a cough that brings up blood. The symptoms of chronic histoplasmosis sometimes can mimic those of tuberculosis.

Diagnosis : Diagnosing histoplasmosis can be complicated, depending on the area of the body affected.

While testing is not usually necessary for mild cases of histoplasmosis, it can be crucial to help choose appropriate treatments in life-threatening cases.

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Your doctor may suggest a combination approach to search for evidence of the disease in samples of: a. b. c. d.

Lung secretions Blood or urine Biopsied lung tissue Bone marrow

Treatment: Treatment usually isn't necessary if you have a mild case of histoplasmosis. But if your symptoms are severe or if you have the chronic or disseminated forms of the disease, you'll likely need treatment with one or more antifungal drugs. Some of these medications come in pill form, but the strongest varieties are administered intravenously. Itraconazole is one type of antifungal medication that’s commonly used to treat histoplasmosis. Depending on the severity of the infection and the person’s immune status, the course of treatment can range from 3 months to 1 year.

Prevention: It's difficult to prevent exposure to the fungus that causes histoplasmosis, especially in areas where the disease is widespread. Even so, these steps may help reduce the risk of infection: a. Avoid exposure. Avoid projects and activities that might expose you to the fungus, such as cave exploring and raising birds, such as pigeons or chickens. b. Spray contaminated surfaces. Before you dig soil or work in an area that could harbor the fungus that causes histoplasmosis, spray it thoroughly with water. This can help prevent spores from being released into the air. Spraying chicken coops and barns before cleaning them also can reduce your risk. c. Use an effective face mask. Wear a respirator mask. Consult the National Institute for Occupational Safety and Health to determine which type of mask will provide adequate protection for your level of exposure.

3. Pneumocystis pneumonia- It Is a serious infection that causes inflammation and fluid buildup in your lungs.

Causative agent :Pneumocystis jiroveci Incubation period : long incubation period, ranging from approximately 3-12 weeks Mode of Transmission : via the airborne route Vaccine : no vaccine Symptoms : a. Fever b. Cough A Self-regulated Learning Module

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c. d. e. f.

Difficulty breathing Chest pain Chills Fatigue (tiredness)

Diagnosis and Testing : a. PCP is diagnosed using a sample from a patient’s lungs. The sample is usually mucus that is either coughed up by the patient (called sputum) or collected by a procedure called bronchoalveolar lavage. b. Sometimes, a small sample of lung tissue (a biopsy) is used to diagnose PCP. The patient’s sample is sent to a laboratory, usually to be examined under a microscope. c. Polymerase chain reaction (PCR) can also be used to detect Pneumocystis DNA in different types of samples.d d. A blood test to detect β-D-glucan (a part of the cell wall of many different types of fungi) can also help diagnose

Treatment and Outcomes : PCP must be treated with prescription medicine. Without treatment, PCP can cause death. The most common form of treatment is trimethoprim/sulfamethoxazole (TMP/SMX), which is also known as co-trimoxazole and by several different brand names, including Bactrim, Septra, and Cotrim. This medicine is given by mouth or through a vein for 3 weeks. *TMP/SMX can cause side effects such as rash and fever.

4. Cryptococcosis- Is a pulmonary or disseminated infection. Cryptococcosis usually affects the lungs or the central nervous system (the brain and spinal cord), but it can also affect other parts of the body. Brain infections due to the fungus Cryptococcus are called cryptococcal meningitis.

Causative agent: Cryptococcus neoformans or C. gattii Incubation period: Unknown Mode of transmission : The infection may be spread to humans through contact with pigeon droppings or unwashed raw fruit. Contact with an infected individual may also spread the infection. Inhalation of airborne fungi. Cryptococcosis is not known to be spread from person to person.

Vaccine : no vaccine Signs and symptoms: A Self-regulated Learning Module

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The majority of symptoms of cryptococcosis occur in the lungs, the brain, or both. The following is a list of the major symptoms: a. Fever b. Malaise c. Pleuritic chest pain (sharp pain that occurs over the area of inflammation and increases with breathing movements) d. Cough, usually nonproductive e. Hemoptysis (bloody or blood tinged sputum) f. Headache g. Vision changes (blurry or double vision, photophobia) h. Nausea and vomiting i. Mental status changes (lethargy, confusion) j. Meningitis k. Seizures l. Coma m. Some people may develop skin changes (rash, pustules, nodules, ulcers).

Diagnosis : a. Culture of CSF, sputum, urine, and blood b. Fixed-tissue specimen staining c. Serum and CSF testing for cryptococcal antigen Prevention Neoformans is commonly spread by bird droppings, especially pigeon droppings. People who have weakened immune systems should avoid areas contaminated by bird droppings, and should avoid contact with birds. There are no formal recommendations for the prevention of C. gattii infection.

Treatment: Patients who are not immune compromised usually are treated with amphotericin B alone (about six to 10 weeks) or combined with flucytosine (about two weeks). These treatments are then followed by fluconazole treatment for at least 10 additional weeks. This treatment is used for brain and severe lung infections.

Antifungal therapy is usually extended until spinal fluid is negative in patients with brain infections, and lung lesions should show a size decrease in response to therapy. Mild infections in the lung may resolve without treatment but must be monitored to be sure reactivation or slow advancement of the infection does not occur.

Immunocompromised patients are treated as above but usually with only intravenously administered (IV) drugs at the start of treatment, and the length of treatment may range from about one to two years to a lifetime of suppressive therapy, usually with fluconazole. Regular medical checkups to determine if cryptococcosis is reactivated or lesions increase in size.

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1. Cryptococcosis Is an infection with parasitic worms.

Causative Agent Caused by infection with a number of species of trematodes belonging to the genus Paragonimus.

The most common are: P. westermani, P. heterotremus and P. philippinensis in Asia (China, the Democratic People’s Republic of Korea, the Republic of Korea, the Lao People’s Democratic Republic, the Philippines, Thailand, Viet Nam and other east Asian countries); P. africanus and P. uterobilateralis in western and central Africa; P. caliensis, P. kellicotti and P. mexicanus in north, central and south America. Adult flukes may measure up to 20 mm x 10 mm.

Figure 19

Source: cdc.gov

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Figure 20

Source: newsmedical.net

The adult flukes live in the lungs and lay eggs that are coughed up through the airways and either expectorated in the sputum or swallowed and defecated. When they reach freshwater, the eggs develop into miracidia that penetrate various species of aquatic snails, where they further develop and reproduce asexually, giving rise to cercariae (larvae).

Cercariae released into water swim to penetrate suitable species of freshwater crabs, crayfish and other crustaceans and encyst the gills, liver and muscles as metacercariae. When such animals are eaten, the metacercariae hatch in the intestine: young worms penetrate the intestinal wall and the peritoneum, then the diaphragm and the pleura; they finally reach the lungs, where they live in pairs surrounded by a capsula, thus completing the cycle.

Once swallowed by a person, the worms mature and grow inside the body. Over months, the worms spread through the intestines and belly (abdomen). They penetrate the diaphragm muscle to enter the lungs. Once inside the lungs, the worms lay eggs and can survive for years, causing chronic (long-term) paragonimiasis.

Signs and symptoms : Paragonimiasis causes no symptoms during initial infection. Many people with paragonimiasis never experience any symptoms. When paragonimiasis symptoms do occur, they result from the worms’ location and activity in the body, which change over time.

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b. c. d. e. f.

Ill-feeling (malaise) Diarrhea Belly pain Itching and hives Worms then travel from the belly into the chest. There they can cause respiratory symptoms

Diagnosis, treatment and control : a. Diagnosis of paragonimiasis is suspected on the basis of the clinical picture, on the anamnestic recall of consuming raw crustaceans, on the detection of eosinophilia, and on typical findings of ultrasound, X-ray, computed tomography or magnetic resonance imaging scans. b. Tests to rule out tuberculosis should always be conducted. Confirmation of diagnosis relies on different types of diagnostic techniques: c. parasitological techniques to detect Paragonimus eggs in sputum or stool samples.; the cost and sensitivity of these techniques may vary according to the type of technique used; they can only be employed once worms have reached the lungs and started laying eggs; some quantify the intensity of infection (allowing an estimation of the severity of the infection); d. immunological techniques to detect worm-specific antibodies in serum samples or wormspecific antigens in serum or stool samples; these techniques are usually more sensitive than the commonly used parasitological techniques; detection of antibodies does not distinguish between current, recent and past infections; their ability to quantify intensity of infection is disputed; these techniques are still at an experimental stage. e. molecular techniques such as the polymerase chain reaction are also still at an experimental stage.

Treatment: a. Triclabendazole, 20 mg/kg, in two divided doses of 10 mg/kg, to be administered on the same day, and b. praziquantel 25 mg/kg of body weight, 3 times a day for 3 days, are both WHOrecommended medicines for treatment of paragonimiasis. The former is preferred for the simplicity of its regimen, which ensures higher compliances to treatment.

2.

Ascaris Pneumonitis Ascariasis (as-kuh-RIE-uh-sis) is a type of roundworm infection. These worms are parasites that use your body as a host to mature from larvae or eggs to adult worms.

Adult worms, which reproduce, can be more than a foot (30 centimeters) long.

Smoke inhalation with any burn injury can be potentially fatal. A heavy infestation of Ascaris could further exacerbate the smoke-induced lung injury. After ingested eggs hatch in the small intestine, the larvae penetrate the mucosa and invade the bloodstream and are then carried to the lungs. The larvae break out into the aveolar spaces as they are too large to cross the capillary bed and are carried up the bronchial tree and eventually swallowed.

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Ascaris lumbricoides, which is a species of roundworm. Roundworms are a type of parasitic worm. Infections caused by roundworms are fairly common.

Figure 21

Source: medicalnewstoday.com

Figure 22

Source: cdc.gov

Incubation Period: The life cycle usually takes 4–8 weeks.

Mode of transmission: Transmission occurs when eggs are swallowed from soil contaminated with human faeces or consumed with produce contaminated with soil containing infective eggs. Transmission does not occur from direct person-to-person contact or from fresh faeces.

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Vaccine :No vaccine

Signs and Symptoms : Most people infected with ascariasis have no symptoms. Moderate to heavy infestations cause various symptoms, depending on which part of your body is affected.

In the lungs After you ingest the microscopic ascariasis eggs, they hatch in your small intestine and the larvae migrate through your bloodstream or lymphatic system into your lungs. At this stage, you may experience signs and symptoms similar to asthma or pneumonia, including: a. b. c. d.

Persistent cough Shortness of breath Wheezing After spending six to 10 days in the lungs, the larvae travel to your throat, where you cough them up and then swallow them.

In the intestines The larvae mature into adult worms in your small intestine, and the adult worms typically live in the intestines until they die. In mild or moderate ascariasis, the intestinal infestation can cause: a. Vague abdominal pain b. Nausea and vomiting c. Diarrhea or bloody stools If you have a large number of worms in your intestine, you might have: a. b. c. d. e.

Severe abdominal pain Fatigue Vomiting Weight loss or malnutrition A worm in your vomit or stop

Prevention The best defense against ascariasis is good hygiene and common sense. Follow these tips to avoid infection: a. Practice good hygiene. Before handling food, always wash your hands with soap and water. Wash fresh fruits and vegetables thoroughly. b. Use care when traveling. Use only bottled water, and avoid raw vegetables unless you can peel and wash them yourself. As a rule, eat only foods that are cooked and hot.

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Treatment : Typically, only infections that cause symptoms need to be treated. In some cases, ascariasis will resolve on its own.

Medications Anti-parasite medications are the first line of treatment against ascariasis. The most common are: a. Albendazole (Albenza) b. Ivermectin (Stromectol) c. Mebendazole These medications, taken for one to three days, kill the adult worms. Side effects include mild abdominal pain or diarrhea.

Surgery In cases of heavy infestation, surgery may be necessary to remove worms and repair damage they've caused. Intestinal obstruction or perforation, bile duct obstruction, and appendicitis are complications that may require surgery.

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Unit 5: Check for Facts and Understanding Microbial Infection of the Respiratory System EVALUATE Instructions: Choose the best answers. Letters ONLY

1.

2.

3.

4.

Which of the following are the signs and symptoms of diphtheria except? a.

A thick, gray membrane covering your throat and tonsils

b.

Difficulty breathing or rapid breathing

c.

Wheezing and coughing

d.

Swollen glands (enlarged lymph nodes) in your neck

What is the mode of transmission of tuberculosis? a.

Ingestion of stool containing microorganisms

b.

Touching infected person

c.

Air droplets during sneezing and coughing

d.

Skin to skin contact

Tuberculosis is an infectious disease transmitted by what organism? a.

Mycobacterium tuberculosis

b.

Mycobacterium diphtheria

c.

Staphylococcus tuberculosis

d.

Bordetella pertussis

Which of the following is not is not a symptom of active TB ? a.

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5.

b.

Weight gain

c.

Chills, night sweats

d.

Fever

What is the causative agent that causes pneumonia ? a.

M. pneumonia

b.

S. pneumonia

c.

Bordetella pertussis

d.

Pneumococcal Pneumonia

EXPLORE Answer the following Questions.

1. What are the complications of Diphtheria ? a. b. c.

2. Two types of TB? a. b.

3. Laboratory test for TB? a. b.

4. Diagnosis for Diphtheria? a. b. c.

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Name:____________________________________________________________ Score:____________ Date Performed :___________________ Date submitted:___________________ Group no. _________ Facilitator:________________________________________________________ Section:___________ ACTIVITY 5 PHYSICAL STERILIZATION

I. OBJECTIVE: The students are expected to categorize the different chemical microorganisms and to discuss the principles of each method.

means of eliminating

II. DISCUSSION Even though physical sterilization is commonly seen as a means of sterilization in the laboratory, chemical agents are more universally used. The chemical agents’ actions on microbes include damage to DNA, protein denaturation, disruption of the cell membrane, or cell wall and the removal of free sulfhydryl group.

As with physical sterilization, there are several factors which affect these actions, such as temperature, concentration of the chemical and the length of time of the microbe’s exposure to the chemical. These factors may be expressed as follows: N = 1/CT Where : N = number of surviving microbes C = concentration T = time For this equation, we can conclude that as the concentration of a disinfectant is increased, the number of surviving microbe is decreased and as the time of exposure of the microbe to the disinfectant is increased, the number of surviving microbe is decreased.

III. MATERIALS Pencil, PPEs (lab gown), Reference materials Equipment: Autoclave, hot air oven

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IV. PROCEDURES 1. Draw and label the parts of the different equipment stated above

A.

SCORING RUBRIC

5

OUTSTANDING; No mistake identified

5 points for each

4

EXCELLENT; 2 Mistakes or missing concepts identified

questions

3

GOOD; 3 mistakes or missing concepts identified

2

FAIR; 4 mistakes or missing concepts identified

1

POOR; 5 mistakes or missing concepts is identified

0

The answer is totally different from the expected response

1. Autoclave

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2. Hot air oven

V. Questions for research 1. What is the principle of operation of the following instruments? a. autoclave –

b. hot air oven -

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c. biological safety cabinet -

2. Explain the principle of the following methods of physical sterilization:

a. boiling -

b. pasteurization

c. incineration

d. dessication

e. filtration

f. osmotic pressure

g. radiation

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3. What is the purpose of the following in the quality control measures of the autoclave? a. test tape

4. Differentiate antiseptic form disinfectant

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INFECTION OF THE DIGESTIVE SYSTEM

Anatomy of the Digestive system Figure 23

Source: Healthdirect.com

Bacterial

1. Shigellosis Is an intestinal disease caused by a family of bacteria known as shigella. The main sign of shigella infection is diarrhea, which often is bloody.

Causative agent: Shigella bacteria

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Figure 24

Source: Healthdirect.com

Mode of Transmission: Shigella can be passed through direct contact with the bacteria in the stool. For example, this can happen in a child care setting when staff members don't wash their hands well enough after changing diapers or helping toddlers with toilet training. Shigella bacteria also can be passed in contaminated food or by drinking or swimming in contaminated water.

Children under age 5 are most likely to get shigella infection, but it can occur at any age.

Signs and Symptoms : a. Diarrhea (often containing blood or mucus) b. Abdominal pain or cramps c. Fever d. Although some people have no symptoms after they've been infected with shigella, their feces may still be contagious up to a few weeks.

Causes : Infection occurs when you accidentally swallow shigella bacteria. This can happen when you: a. Touch your mouth. If you don't wash your hands well after changing the diaper of a child who has shigella infection, you may become infected yourself. Direct person-to-person contact is the most common way the disease is spread. b. Eat contaminated food. Infected people who handle food can transmit the bacteria to people who eat the food. Food can also become contaminated if it grows in a field that contains sewage. c. Swallow contaminated water. Water may become contaminated either from sewage or from a person with shigella infection swimming in it.

Diagnosis: a. Diarrhea and bloody diarrhea can result from a number of diseases. Confirming shigellosis involves taking a sample of your stool to be tested in a laboratory for the presence of shigella bacteria or their toxins.

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Treatment : a. Antibiotics- For severe shigella infection, antibiotics may shorten the duration of the illness. However, some shigella bacteria have become drug resistant. So it's better not to take antibiotics unless your shigella infection is severe. b. Fluid and salt replacement- For generally healthy adults, drinking water may be enough to counteract the dehydrating effects of diarrhea. Children may benefit from an oral rehydration solution, such as Pedialyte, available in drugstores.

2. Bacterial gastritis / Ulcer- Gastritis is an inflammation, irritation, or erosion of the lining of the stomach.

Causative Agent: Helicobacter pylori (H. pylori): A bacteria that lives in the mucous lining of the stomach Figure 25

Source: Webmd.com

Incubation Period : General malaise, nausea, vomiting, stomach cramps, and diarrhea can occur within 30 min of ingestion of the contaminated food. The typical incubation period is 2 to 7 h, with symptoms resolving in about 12 h.

Vaccine: No Vaccine Mode Of Transmission : Mode of transmission of gastroenteritis viruses (not rotavirus) Viral gastroenteritis is predominantly spread via the faecal-oral route. Transmission is facilitated through contaminated food, water (including ice) and person-to-person contact.

Symptoms and symptoms : a. Nausea or recurrent upset stomach b. Abdominal bloating c. Abdominal pain d. Vomiting A Self-regulated Learning Module

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e. f. g. h. i. j.

Indigestion Burning or gnawing feeling in the stomach between meals or at night Hiccups Loss of appetite Vomiting blood or coffee ground-like material Black, tarry stools

Diagnosis : a. Upper endoscopy. An endoscope, a thin tube containing a tiny camera, is inserted through your mouth and down into your stomach to look at the stomach lining. The doctor will check for inflammation and may perform a biopsy, a procedure in which a tiny sample of tissue is removed and then sent to a laboratory for analysis. b. Blood tests. The doctor may perform various blood tests, such as checking your red blood cell count to determine whether you have anemia, which means that you do not have enough red blood cells. He or she can also screen for H. pylori infection and pernicious anemia with blood tests. c. Fecal occult blood test (stool test). This test checks for the presence of blood in your stool, a possible sign of gastritis.

Treatment: a. antacids and other drugs (such as proton pump inhibitors or H-2 blockers) to reduce stomach acid b. Avoiding hot and spicy foods c. For gastritis caused by H. pylori infection, your doctor will prescribe a regimen of several antibiotics plus an acid blocking drug (used for heartburn) d. If the gastritis is caused by pernicious anemia, B12 vitamin shots will be given. e. Eliminating irritating foods from your diet such as lactose from dairy or gluten from wheat.

3. Campylobacter enteritis It is a gram negative bacteria most commonly associated with the consumption of undercooked poultry meat and is a common bacterium found in the intestinal tracts of dogs, cats, poultry, swine, cattle, monkeys, wild birds and some humans.

Causative agent: Campylobacter jejuni. Other Campylobacter organisms include C. coli, C. fetus and C. lari.

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Figure 26

Vaccine : No vaccine Mode of transmission : Ingestion of infected undercooked meats and meat products, especially poultry.Ingestion of unpasteurized or contaminated milk, contaminated ice and water.

Incubation period : Commonly 2-5 days with a range of 1-10 days.

Signs and symptoms : Campylobacter jejuni causes an acute bacterial disease of varying severity that is characterized by a. diarrhea b. abdominal pain c. malaise d. Fever e. nausea and vomiting f. The disease is often associated with gross or occult blood and mucus in liquid stools.

Diagnosis : Diagnosis of this organism is best completed by isolating the organism from a stool sample.

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Treatment : This disease is self limiting and there is no specific recommended treatment other than rehydration and electrolyte replacement. In some cases, physicians prescribe antibiotics such as erythromycin or ciprofloxacin when diarrhea is severe.

4. Cholera An infectious and often fatal bacterial disease of the small intestine, typically contracted from infected water supplies and causing severe vomiting and diarrhea.

Causative agent :Vibrio cholera Figure 27

Incubation period : The incubation period is from a few hours to 5 days; it is usually 2–3 days.

Mode of transmission : The cholera bacterium is usually found in water or food sources that have been contaminated by feces (poop) from a person infected with cholera. Cholera is most likely to be found and spread in places with inadequate water treatment, poor sanitation, and inadequate hygiene.

Vibrio cholerae, the bacterium that causes cholera, is usually found in food or water contaminated by feces from a person with the infection. Common sources include: a. Municipal water supplies b. Ice made from municipal water c. Foods and drinks sold by street vendors d. Vegetables grown with water containing human wastes e. Raw or undercooked fish and seafood caught in waters polluted with sewage A Self-regulated Learning Module

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Vaccine : The FDA recently approved External a single-dose live oral cholera vaccine called Vaxchora® (lyophilized CVD 103-HgR) for adults 18 – 64 years old who are traveling to an area of active cholera transmission with toxigenic Vibrio cholerae O1 (the bacteria strain that most commonly causes cholera).

Symptoms Symptoms of cholera can begin as soon as a few hours or as long as five days after infection.

Often, symptoms are mild. But sometimes they are very serious. About one in 20 people infected have severe a. watery diarrhea accompanied by vomiting, which can quickly lead to dehydration. Although many infected people may have minimal or no symptoms, they can still contribute to spread of the infection. b. Rapid heart rate c. Loss of skin elasticity (the ability to return to original position quickly if pinched) d. Dry mucous membranes, including the inside of the mouth, throat, nose, and eyelids e. Low blood pressure f. Thirst g. Muscle cramps h. If not treated, dehydration can lead to shock and death in a matter of hours.

Treatment and Prevention : Although there is a vaccine against cholera, the CDC and World Health Organization don't normally recommend it, because it may not protect up to half of the people who receive it and it lasts only a few months. However, you can protect yourself and your family by using only water that has been boiled, water that has been chemically disinfected, or bottled water. Be sure to use the bottled, boiled, or chemically disinfected water for the following purposes: a. b. c. d. e. f. g.

Drinking Preparing food or drinks Making ice Brushing your teeth Washing your face and hands Washing dishes and utensils that you use to eat or prepare food Washing fruits and vegetables

*To disinfect your own water, boil it for one minute (or 3 minutes at higher elevations) or filter it and use a commercial chemical disinfectant. *If you develop severe, watery diarrhea and vomiting -- particularly after eating raw shellfish or traveling to a country where cholera is epidemic -- seek medical help immediately. Cholera is highly treatable, but because dehydration can happen quickly, it's important to get cholera treatment right away.

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*Hydration is the mainstay of treatment for cholera. Depending on how severe the diarrhea is, treatment will consist of oral or intravenous solutions to replace lost fluids. Antibiotics, which kill the bacteria, are not part of emergency treatment for mild cases. But they can reduce the duration of diarrhea by half and also reduce the excretion of the bacteria, thus helping to prevent the spread of the disease.

5. Salmonellosis Is a common bacterial disease that affects the intestinal tract. Salmonella bacteria typically live in animal and human intestines and are shed through feces. Humans become infected most frequently through contaminated water or food.

Causative agent :Salmonella bacteria

Figure 28

Source: microbewiki.com

Incubation period : usually 6–72 hours, with an average of 12–36 hours.

Mode Of transmission: Transmission is usually person-to-person or animal-to-person via the faecal–oral route, through ingestion of the organisms via contaminated or improperly cooked foods. Foodborne transmission occurs particularly with: raw and undercooked eggs and egg products.

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Vaccine :There is no vaccine currently available for salmonella poisoning. However, oral vaccination is the simplest and least invasive way to protect people against salmonella infection.

Taking this vaccine by mouth also has the added advantage of using the same pathway that salmonella uses to wreak havoc on the digestive system.

Signs and Symptoms: a. Nausea b. Vomiting c. Abdominal cramps d. Diarrhea e. Fever f. Chills g. Headache h. Blood in the stool *Signs and symptoms of salmonella infection generally last two to seven days. Diarrhea may last up to 10 days, although it may take several months before bowels return to normal.

Causes : Salmonella bacteria live in the intestines of people, animals and birds. Most people are infected with salmonella by eating foods that have been contaminated by feces. Commonly infected foods include: a. Raw meat, poultry and seafood. Feces may get onto raw meat and poultry during the butchering process. Seafood may be contaminated if harvested from contaminated water. b. Raw eggs. While an egg's shell may seem to be a perfect barrier to contamination, some infected chickens produce eggs that contain salmonella before the shell is even formed. Raw eggs are used in homemade versions of mayonnaise and hollandaise sauce. c. Fruits and vegetables. Some fresh produce, particularly imported varieties, may be hydrated in the field or washed during processing with water contaminated with salmonella. Contamination also can occur in the kitchen, when juices from raw meat and poultry come into contact with uncooked foods, such as salads.

Diagnosis : Salmonella infection can be detected by testing a sample of your stool. However, most people have recovered from their symptoms by the time the test results return.If doctor suspects that you have a salmonella infection in your bloodstream, he or she may suggest testing a sample of your blood for the bacteria.

Treatment : Medications

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a. Because salmonella infection can be dehydrating, treatment focuses on replacing fluids and electrolytes. Severe cases may require hospitalization and fluids delivered directly into a vein (intravenous). In addition, your doctor may recommend: b. Anti-diarrheals. Medications such as loperamide (Imodium A-D) can help relieve cramping, but they may also prolong the diarrhea associated with salmonella infection. c. Antibiotics. If your doctor suspects that salmonella bacteria have entered your bloodstream, or if you have a severe case or a compromised immune system, he or she may prescribe antibiotics to kill the bacteria. Antibiotics are not of benefit in uncomplicated cases. In fact, antibiotics may prolong the period in which you carry the bacteria and can infect others, and they can increase your risk of relapse.

6. Typhoid Fever - is an acute infectious illness associated with fever that is most often caused by the Salmonella typhi bacteria. It can also be caused by Salmonella paratyphi, a related bacterium that usually leads to a less severe illness.

Causative agent : Salmonella typhi Figure 29

Source: thescientist.com

Incubation period : usually 8–14 days Vaccine : There are two vaccines available to prevent typhoid fever: Vivotif (Typhoid Vaccine Live Oral Ty21a) – Also known as 'typhoid pills', Vivotif is made from attenuated live bacteria. The vaccine provides up to five years' protection and is approved for use in individuals over six-years-old. ● ●

The typhoid shot The oral typhoid vaccine (swallowed as a pill)

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The bacteria that cause typhoid fever spread through contaminated food or water and occasionally through direct contact with someone who is infected. In developing nations, where typhoid fever is established (endemic), most cases result from contaminated drinking water and poor sanitation.

Signs and symptoms a. b. c. d. e. f. g. h. i. j. k. l.

Fever that starts low and increases daily, possibly reaching as high as 104.9 F (40.5 C) Headache Weakness and fatigue Muscle aches Sweating Dry cough Loss of appetite and weight loss Abdominal pain Diarrhea or constipation Rash Extremely swollen abdomen Later illness

*If you don't receive treatment, you may: Become delirious Complications : Intestinal bleeding or holes The most serious complications of typhoid fever — intestinal bleeding or holes (perforations) in the intestine — may develop in the third week of illness. A perforated intestine occurs when your small intestine or large bowel develops a hole, causing intestinal contents to leak into your abdominal cavity and triggering signs and symptoms such as severe abdominal pain, nausea, vomiting and bloodstream infection (sepsis). This life-threatening complication requires immediate medical care. a. b. c. d. e. f.

Other, less common complications Other possible complications include:

Inflammation of the heart muscle (myocarditis) Inflammation of the lining of the heart and valves (endocarditis) Pneumonia Inflammation of the pancreas (pancreatitis) Kidney or bladder infections Infection and inflammation of the membranes and fluid surrounding your brain and spinal cord (meningitis)

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Treatment : If typhoid fever is diagnosed early, the infection is likely to be mild and can usually be treated at home with a 7- to 14-day course of antibiotic tablets.

Medicine : a. Ciprofloxacin (Cipro). b. ofloxacin also may be used. Unfortunately, many Salmonella typhi bacteria are no longer susceptible to antibiotics of this type, particularly strains acquired in Southeast Asia. c. Azithromycin (Zithromax). This may be used if a person is unable to take ciprofloxacin or the bacteria is resistant to ciprofloxacin. d. Ceftriaxone. This injectable antibiotic is an alternative in more-complicated or serious infections and for people who may not be candidates for ciprofloxacin, such as children.

7. Leptospirosis is a relatively rare bacterial infection that affects people and animals. It can pass from animals to humans when an unhealed break in the skin comes in contact with water or soil where animal urine is present.

Causative agent : Leptospira interrogans Figure 30

Source: healthdirect.com

Figure 31

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Incubation period : approximately seven to 12 days but it may range from two to 30 days.

Mode of Transmission : The infection may also be transmitted through direct contact with urine or tissues of infected animals, or by inhalation of aerosols of contaminated fluids, such as may occur in abattoirs.

Ingestion of foods contaminated with urine of infected rats is an occasional route of infection.

Vaccine : Although some leptospirosis vaccines have been obtained, the vaccination is relatively unsuccessful.

Signs and Symptoms : You usually start showing signs of leptospirosis within 2 weeks, though in some cases, symptoms may not show up for a month or not at all. a.

fever. It may spike to 104 F.

b. c. d. e. f. g.

Headache Muscle ache Jaundice (yellowing of the skin and eyes) Vomiting Diarrhea Skin rash

Treatment : a. antibiotics, including penicillin and doxycycline. b. ibuprofen for fever and muscle pain.

8. Enteropathogenic E. coli infection Is a common cause of watery diarrhea in children in the developing world and an infrequent cause of significant diarrhea in adult patients.

Causative Agent : Diarrheagenic E. coli (DEC) Enteropathogenic Escherichia coli (EPEC)

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Figure 32

Source: shutterstock.net

Incubation Period : E. coli infections have an incubation period ranging from 8 hours to 3 days. The median incubation period of infections is 3–4 days, with a range of 1–10 days.

Mode of Transmission : E. is transmitted to humans primarily through consumption of contaminated foods, such as raw or undercooked ground meat products and raw milk. ... Person-to-person contact is an important mode of transmission through the oral-faecal route.

Vaccine : No vaccine Signs and Symptoms :

a. Diarrhea, which may range from mild and watery to severe and bloody b. Abdominal cramping, pain or tenderness c. Nausea and vomiting, in some people d.

8 1.

2.

3.

4.

5.

6.

7.

8.

early signs and symptoms of E. coli infection Nausea Vomiting Stomach cramps (abdominal pain) Diarrhea that often is bloody Fever of about 100 F to 101 F (37.7 C to 38.3 C) Malaise Loss of appetite Mild dehydration

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Diagnosis Sample of your stool to a laboratory to test for the presence of E. coli bacteria. The bacteria may be cultured to confirm the diagnosis and identify specific toxins, such as those produced by E. coli Treatment For illness caused by E. coli, no current treatments can cure the infection, relieve symptoms or prevent complications. For most people, treatment includes: a. Rest b. Fluids to help prevent dehydration and fatigue c. Avoid taking an anti-diarrheal medication — this slows your digestive system down, preventing your body from getting rid of the toxins. Antibiotics generally aren't recommended because they can increase the risk of serious complications. d. If you have a serious E. coli infection that has caused hemolytic uremic syndrome, you'll be hospitalized and given supportive care, including IV fluids, blood transfusions and kidney dialysis.

9. Enterotoxigenic E. Coli ETEC, is the name given to a group of E. coli that produce special toxins which stimulate the lining of the intestines causing them to secrete excessive fluid, thus producing diarrhea.

(ETEC) are bacteria that cause disease in humans and domestic animals by producing a heat labile or heat stable toxin or both. The disease is also known as “Traveler’s Diarrhea.” Although ETEC is a frequent cause of diarrhea in developing countries Causative agent : called enterotoxigenic E

Escherichia

coli strains

that

produce

enterotoxins

are

Figure 33

Source: medicalnewstoday.com

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Figure 34

Incubation Period : The incubation period associated with infection of this group of E. coli is 12–72 hours, with duration of illness often 3–5 days.

Vaccine :no vaccine Mode of transmission : ETEC is transmitted by food or water contaminated with animal or human feces. fecal-oral route.

Signs and Symptoms : a. Diarrhea, which may range from mild and watery to severe and bloody b. Abdominal cramping, pain or tenderness c. Nausea and vomiting, in some people

Diagnosis : a. Bacteria are cultured from samples of stool.

Supportive care : The mainstay of treatment for EHEC infection is supportive. Although E. coli is sensitive to most commonly used antibiotics, antibiotics have not been shown to alleviate symptoms, reduce carriage of the organism, or prevent hemolytic-uremic syndrome. Fluoroquinolones are suspected of increasing release of enterotoxins and the risk of hemolytic-uremic syndrome.

In the week after infection, patients at high risk of developing hemolytic-uremic syndrome (eg, children < 5 years, older people) should be observed for early signs, such as hemolytic anemia, thrombocytopenia, proteinuria, hematuria, red cell casts, and rising serum creatinine. Edema and hypertension develop later. Patients who develop complications are likely to require intensive care, including dialysis and other specific therapies, at a tertiary medical center.

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10. Enteroinvasive E. coli Infection (EIEC) is a type of pathogenic bacteria whose infection causes a syndrome that is identical to shigellosis, with profuse diarrhea and high fever. ... The invasion of the cells can trigger a mild form of diarrhea or dysentery, often mistaken for dysentery caused by Shigella species.

Causative Agent : Shigella spp. and Enteroinvasive Escherichia coli. Bacillary dysentery is caused by Shigella spp.

Figure 35

Source: wikipedia.ORG

Incubation Period : ranges from 6 hours to 9 days but is usually less than 72 hours.

Mode of Transmission : Fecal-oral route; fecal contamination of water, food Vaccine : No vaccine is available Signs and Symptoms : a. signs of dehydration (for example, decreased urination, dry mucous membranes), especially in children under 5 years of age and the elderly; b. sustained fever over 101 F (37.7 C); c. presence of blood in the stool. d. abdominal cramps, malaise, tenesmus Diagnosis : a. Stool Exams Treatment : a. profuse diarrhea or vomiting should be rehydrated. Evidence from studies of children with STEC O157 infection indicates that early use of intravenous fluids (within the first 4 days of diarrhea onset) may decrease the risk of oligoanuric renal failure. b. Antibiotics to treat non-STEC diarrheagenic E. coli include fluoroquinolones such as ciprofloxacin, macrolides such as azithromycin, and rifaximin. Clinicians treating a patient whose clinical syndrome suggests STEC infection should be aware that A Self-regulated Learning Module

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administering certain antimicrobial agents may increase the risk of HUS. Resistance to antibiotics is increasing worldwide.

Food Poisoning 1.

Botulism Is a rare but serious condition caused by toxins from bacteria called Clostridium botulinum.

Three common forms of botulism are: a. Foodborne botulism. The harmful bacteria thrive and produce the toxin in environments with little oxygen, such as in home-canned food. b. Wound botulism. If these bacteria get into a cut, they can cause a dangerous infection that produces the toxin. c. Infant botulism. This most common form of botulism begins after Clostridium botulinum bacterial spores grow in a baby's intestinal tract. It typically occurs in babies between the ages of 2 months and 8 months.

Causative Agent :Clostridium botulinum Figure 36

source: cdc.gov

Figure 37

Source: cdbioscience.com

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Incubation Period : 12–72 hours after ingestion Mode of Transmission Develops if a person ingests the toxin (or rarely, if the toxin is inhaled or injected) or if the organism grows in the intestines or wounds and toxin is released. Foodborne botulism is spread by consuming food contaminated with the botulism toxin or spores.

Vaccine : No approved vaccine Signs and Symptoms : a. Difficulty swallowing or speaking. b. Dry mouth. c. Facial weakness on both sides of the face. d. Blurred or double vision. e. Drooping eyelids. f. Trouble breathing. g. Nausea, vomiting and abdominal cramps. h. Paralysis.

Diagnosis : a. Complete a physical exam, noting any signs or symptoms of botulism poisoning. They’ll ask about foods eaten within the past several days as possible sources of the toxin, and if anyone else ate the same food. *Some symptoms of botulism can mimic those of other diseases and conditions. Your doctor may order additional tests to rule out other causes. These tests may include: a. electromyography (EMG) to evaluate muscle response b. imaging scans to detect any internal damage to the head or brain c. spinal fluid test to determine if infection or injury to the brain or spinal cord is causing symptoms Treatment : a. antibiotics. b. antitoxin (a chemical antidote to the toxin). c. good nursing support and physician care, sometimes in an intensive care unit, with machine support by a ventilator as needed to assist breathing.

2. Staphylococcal Food Poisoning and intoxication Is a gastrointestinal illness caused by eating foods contaminated with toxins.

Causative Agent : bacterium Staphylococcus aureus (Staph) bacteria

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Figure 38

Incubation Period : Staphylococcal enterotoxins are heat- resistant and are not inactivated by cooking. Outbreak Potential: Staphylococci have moderate outbreak potential if transmitted by food. Incubation period: between 2 and 4 hours (range 30 minutes to 8 hours).

Vaccine : No vaccine Mode of Transmission : These bacteria are spread by having direct contact with an infected person, by using a contaminated object, or by inhaling infected droplets dispersed by sneezing or coughing. Skin infections are common, but the bacteria can spread through the bloodstream and infect distant organs.

Signs and symptoms : Staph food poisoning is characterized by a sudden start of a. Nausea b. vomiting c. stomach cramps d. Most people also have diarrhea.

Diagnosis : Staphylococcal food poisoning can be confirmed if the enterotoxin or large numbers of S. aureus are found in the food. S. aureus can also be detected in stool samples from patients.

Treatment : a. The most important treatment is drinking plenty of fluids. Your healthcare provider may give you medicine to decrease vomiting and nausea. People with severe illness may require intravenous fluids. b. Antibiotics are not useful in treating this illness because the toxin is not affected by antibiotics.

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3.

Clostridium Perfringens infection is acute gastroenteritis caused by ingestion of contaminated food.

Causative agent : Clostridium perfringens Figure 39

Source: healthdirect.com

Incubation Period : range from 6 to 24 hours.

Mode of Transmission : Ingestion of food contaminated by soil or feces, held under conditions which permit multiplication of the organism (inadequately cooked or reheated meats) Vaccine :No vaccine Signs and symptoms : a. watery diarrhea b. nausea, vomiting c. abdominal pain d. fever. 8-12 hours, but can take up to 24 hours from ingestion. ● Duration of symptoms is typically less than 24 hours.

Diagnosis : a. Detecting a type of bacterial toxin in feces or by tests to determine the number of bacteria in the feces. A count of at least 106 C. perfringens spores per gram of stool within 48 hours of when illness began is required to diagnose infection.

Treatment : a. Oral rehydration or, in severe cases, intravenous fluids and electrolyte replacement can be used to prevent or treat dehydration.

Antibiotics are not recommended.

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VIRAL 1. Gastroenteritis Is an inflammation of the lining of the intestines caused by a virus, bacteria, or parasites.

Causative Agent : Viruses (particularly rotavirus) and the bacteria Escherichia coli and Campylobacter species are the primary causes of gastroenteritis. There are, however, many other infectious agents that can cause this syndrome including parasites and fungus.

Figure 40

Source: Wedmd.com

Figure 41

Source: wikipedia.org

Incubation Period :usually 24–48 hours.

Mode of Transmission : Spread via the faecal-oral route. Transmission is facilitated through contaminated food, water (including ice) and person-to-person contact

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Vaccine : rotavirus vaccine Signs And Symptoms : a. Watery, usually nonbloody diarrhea — bloody diarrhea usually means you have a different, more severe infection. b. Abdominal cramps and pain. c. Nausea, vomiting or both. d. Occasional muscle aches or headache. e. Low-grade fever Diagnosis : a. routine stool culture Treatment : Treatment depends on the cause, but may include: a. plenty of fluids b. oral rehydration drinks, available from your pharmacist c. admission to hospital and intravenous fluid replacement, in severe cases d. antibiotics, if bacteria are the cause e. drugs to kill the parasites, if parasites are the cause f. avoiding anti-vomiting or anti-diarrhoea drugs unless prescribed or recommended by your doctor, because these medications will keep the infection inside your body.

2. Hepatitis A Is a highly contagious liver infection caused by the hepatitis A virus. Some people have a mild illness that lasts a few weeks. Others have more severe problems that can last months. You usually get it when you eat or drink something that’s been exposed to poop from someone who has the virus.

Causative agent : Hepatitis A virus (HAV)

Figure 42

Source: shuttershock.com

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Figure 43

Mode of transmission : The hepatitis A virus is transmitted primarily by the faecal-oral route; that is when an uninfected person ingests food or water that has been contaminated with the faeces of an infected person.Waterborne outbreaks, though infrequent, are usually associated with sewagecontaminated or inadequately treated water.

Incubation period :usually 14–28 days Vaccine : Hepatitis A vaccine (Havrix, Vaqta) is used to prevent hepatitis A, a type of liver disease that is caused by the hepatitis A virus (HAV). ... Getting vaccinated against the hepatitis A virus is the best way to prevent these problems.

Symptoms of Hepatitis A If you have this infection, you have inflammation in your liver that's caused by a virus. You don't always get symptoms, but when you do, you might have: a. b. c. d. e. f. g. ●

Jaundice (yellow eyes and skin, dark urine) Pain in your belly Loss of appetite Nausea Fever Diarrhea Fatigue

You can spread the hepatitis A virus about 2 weeks before your symptoms appear and during the first week they show up.

Causes Hepatitis A :

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You can catch the disease if you drink water or food that's been contaminated with the stool of someone with the virus.

- Hepatitis transmission can also happen if you: a. Eat fruits, vegetables, or other foods that were contaminated during handling b. Eat raw shellfish harvested from water that's got the virus in it c. Swallow contaminated ice Diagnosis : a. IgM (immunoglobulin M) antibodies. Your body makes these when you’re first exposed to hepatitis A. They stay in your bloodstream for about 3 to 6 months. b. IgG ( immunoglobulin G) antibodies. These show up after the virus has been in your body for a while. You may have them all your life. They protect you against hepatitis A for the rest of your life. If you test positive for them but not for IgM antibodies, it means you had a hepatitis A infection in the past or you’ve been vaccinated against it.

Treatment : There is no specific medication.Your doctor will treat your symptoms -- you may hear this called supportive care -- until the disease goes away. He’ll also do tests that check how well your liver is working to be sure your body is healing. ● During that time, you can take these steps to make yourself more comfortable: a. Get some rest. You’ll probably feel tired, sick, and have less energy than before you were infected. b. Try to keep food down. The nausea that comes with hepatitis A can make it tough to eat.

It may be easier to snack during the day than to eat full meals. To make sure you get enough, go for more high-calorie foods and drink fruit juice or milk instead of water.

Fluids will also help keep you hydrated if you’re throwing up. c. Avoid alcohol. It’s hard for your liver to process medications and alcohol. Plus, drinking can lead to added liver damage. Tell your doctor about any medications you take, including over-the-counter drugs.

3. Hepatitis E is a potentially serious acute disease. The virus targets the liver. is a virus that infects your liver. It can cause your liver to swell up.

Causative Agent: Hepatitis E virus (HEV)

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Figure 44

Source: reachgate.net

Figure 45

Source: thesciencenotes.com

Incubation Period :exposure to HEV ranges from 2 to 10 weeks, with an average of 5 to 6 weeks.

Mode of Transmission : enterically transmitted infection that is typically self-limited. It is caused by the hepatitis E virus (HEV) and is spread by fecally contaminated water within endemic areas or through the consumption of uncooked or undercooked meat. Outbreaks can be epidemic and individual.

Vaccine: Hepatitis E vaccine (HEV 239 vaccine, Hecolin®) Signs And Symptom: a. Mild fever b. Feeling very tired c. Less hunger d. Feeling sick to your stomach e. Throwing up f. Belly pain g. Dark pee A Self-regulated Learning Module

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h. i. j. k.

Light-colored poop Skin rash or itching Joint pain Yellowish skin or eyes

Diagnosis: a. Detection of specific IgM antibodies to the virus in a person’s blood; this is usually adequate in areas where disease is common. Rapid tests are available for field use. b. Additional tests include reverse transcriptase polymerase chain reaction (RT-PCR) to detect the hepatitis E virus RNA in blood and/or stool; this assay requires specialized laboratory facilities. This test is particularly needed in areas where hepatitis E is infrequent, and in cases with chronic HEV infection.

Treatment : There is no specific treatment capable of altering the course of acute hepatitis E. As the disease is usually self-limiting, hospitalization is generally not required. Most important is the avoidance of unnecessary medications. Acetaminophen/Paracetamol and medication against vomiting should not be given.

However, hospitalization is required for people with fulminant hepatitis, and should also be considered for symptomatic pregnant women.

Immunosuppressed people with chronic hepatitis E benefit from specific treatment using ribavirin, an antiviral drug. In some specific situations, interferon has also been used successfully.

Prevention : Prevention is the most effective approach against the disease. At the population level, transmission of HEV and hepatitis E disease can be reduced by: a. maintaining quality standards for public water supplies; and a. establishing proper disposal systems for human faeces.

On an individual level, infection risk can be reduced by: a. maintaining hygienic practices; b. avoiding consumption of water and ice of unknown purity.

4. Adenovirus Infection Are a group of common viruses that infect the lining of your eyes, airways and lungs, intestines, urinary tract, and nervous system. This are a group of viruses that cause a variety of infections, such as: Respiratory illness, such as a cold Infection of the eye (conjunctivitis, also called pink eye) Croup

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Bronchiolitis Pneumonia In children, adenoviruses most often cause infections in the respiratory system, but they also cause infections of the digestive tract. Respiratory infections are most common in the late winter, spring, and early summer. But these infections can occur anytime throughout the year.

Causative agent :Human Adenovirus Figure 46

Source: medicalnews.net

Figure 47

Source: cdc.gov

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Incubation period : 2 to 14 days before he has symptoms. The incubation period for gastroenteritis can range from 3 to 10 days.

Mode of Transmission: The viruses can be spread from person to person via coughing or sneezing. People may also become infected by touching something with adenovirus on it and then touching their mouth, nose, or eyes.

Vaccine: Adenovirus vaccine contains live adenovirus Type 4 and Type 7. It will prevent most illness caused by these two virus types. The vaccine comes as two tablets, taken orally (by mouth) at the same time.

Signs And Symptoms : a. Common cold b. Sore throat c. Bronchitis (a condition that occurs when the airways in the lungs become filled with mucus and may spasm, which causes a person to cough and have shortness of breath) d. Pneumonia (infection of the lungs) e. Diarrhea f. Pink eye (conjunctivitis) g. Fever h. Bladder inflammation or infection i. Inflammation of stomach and intestines j. Neurologic disease (conditions that affect the brain and spinal cord

Diagnosis : a. antigen detection b. polymerase chain reaction (PCR) c. virus isolation, and serology d. Adenovirus typing is usually done by molecular methods.

Treatment: There is no specific treatment for people with adenovirus infection.

Most adenovirus infections are mild and may require only care to help relieve symptoms, such as over-the-counter pain medicines or fever reducers. Always read the label and use medications as directed. There are no approved antiviral medicines for adenovirus infections.

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5. Norwalk Viral Infection Viral gastroenteritis, which is also known as acute nonbacterial gastroenteritis, food poisoning, food infection, stomach flu, and winter vomiting disease.

Causative agent: Noroviruses (genus Norovirus, family Caliciviridae) are a group of related, single stranded RNS, non-enveloped viruses that cause acute gastroenteritis in humans1. Previously referred to as Norwalk-like viruses (NLVs), caliciviruses and as small round structured viruses (SRSVs).

Figure 48

Source: Cdbioscience.com

Figure 49

Source: wikipedia.org

Incubation Period: norovirus-associated gastroenteritis is 12 to 48 hours, with a median period of approximately 33 hours.

Mode Of Transmission: transmitted primarily by the fecal-oral route. Having direct contact with vomit or feces from an infected person and then transferring the virus to the mouth from the hands primarily spreads the viruses. ... These viruses are very contagious and only a few are needed to cause an illness.

Vaccine: a two-dose, intranasally administered, VLP vaccine with adjuvants provided homologous protection against both Norwalk virus–associated viral gastroenteritis and infection.

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Signs and symptoms : a. Nausea b. Vomiting c. Stomach pain or cramps d. Watery or loose diarrhea e. Feeling ill f. Low-grade fever g. Muscle pain Diagnosis: Diagnosis is usually based on your symptoms, but norovirus can be identified from a stool sample.

Treatment: There's no specific treatment for norovirus infection, and recovery generally depends on the health of your immune system. In most people, the illness usually resolves within a few days. a. It's important to replace lost fluids. Oral rehydration solutions may be used. If you're unable to drink enough fluids to prevent dehydration, you might need to receive fluids through a vein. b. anti-diarrheal medication.

4. Astrovirus Infection - A type of virus that causes diarrheal illness (gastroenteritis). Infants and young children are most likely to have diarrhea caused by astroviruses, but the infection also occurs in the elderly and those with compromised immune systems.

Causative Agent: Astroviruses are nonenveloped, positive-sense single-stranded RNA viruses in the family Astroviridae. ... Nonserotype 1 viruses can predominate in a season, and greater serotype diversity may be found in developing countries.

Figure 50

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source: cdc.gov

Figure 51

Source: news.medical.net

Incubation Period: Four to five days is followed by a watery diarrhea lasting from one to four days or more, abdominal discomfort, vomiting, fever, and anorexia.

Mode of Transmission: Frequently transmitted through a fecal-oral route. Transmission is by contaminated food and water.

Vaccine: There are currently no vaccines available to prevent astrovirus infection; Creative Biolabs is developing a trivalent vaccine against Noroviruses, astroviruses, and Hepatitis E viruses, which is a promising vaccine candidate.

Signs and Symptoms : Astroviruses are one of several pathogens that can cause gastroenteritis in humans. The main symptom caused by astrovirus is diarrhea. Compared to other microorganisms that can cause gastroenteritis, such as rotavirus and norovirus, diarrhea caused by astrovirus is usually mild.1 While mild diarrhea is the main symptom astroviruses cause, a person who gets sick may also have other common symptoms of gastroenteritis, including: a. Nausea b. Vomiting A Self-regulated Learning Module

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c. ache d. Loss of appetite e. Body aches f. Fever Diagnosis: a. Astrovirus can usually be diagnosed with a combination of a physical exam, a review of your medical history, and various blood and stool tests. Based on a review of your symptoms and risk factors, your doctor may decide to treat you presumptively if the symptoms are mild. b. Stool culture to visually ad chemically test for astrovirus inn a stool sample c. Enzyme-linked immunosorbent assay (EIA), a blood test that checks for immune proteins, called antibodies, that the body produces in response to infectious microorganisms d. Polymerase chain reaction (PCR) tests able to detect astrovirus RNA in blood Treatment: An illness caused by a virus cannot be treated with antibiotics. Therefore, any treatment prescribed for viral gastroenteritis would be supportive and focused on the management of symptoms (such as the alleviation of nausea or fluid replacement for dehydration).

Unlike some viral diseases, such as the flu, antiviral drugs are not prescribed to treat astrovirus and do little to alter the course of the illness if they are. Neither are there vaccines that can prevent infection.

The only thing you can do to avoid getting or spreading astrovirus is to follow certain commonsense prevention rules. These involve: a. Proper handwashing, especially after using the bathroom b. Not sharing utensils or cups if you or people around you are sick c. Staying home from work or school if you are sick d. Avoiding the handling and preparation of food when sick or while recovering from illness e. Using antiseptic or disinfectants to clean surfaces, especially in the bathroom and kitchen

5. RotaVirus Infection This easily spread virus causes inflammation in the stomach and intestines. From late winter to early spring, it can cause severe diarrhea, vomiting, fever, abdominal pain, and dehydration in infants, young children, and some adults.

Causative Agent: Rotavirus

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Figure 52

Source: microbewiki.com

Incubation Period: About 24 to 72 hours (1 to 3 days) Mode Of Transmission: passage of the virus in stool to the mouth of another child, known as a fecal-oral route of transmission.

Vaccine :Rota Vaccine Signs And Symptoms: A rotavirus infection usually starts within two days of exposure to the virus.

Initial symptoms are a. fever and vomiting b. followed by three to eight days of watery diarrhea. c. The infection can cause abdominal pain as well. d. e. f. g. h. i.

diarrhea for more than 24 hours frequent episodes of vomiting black or tarry stool or stool containing blood or pus temperature of 104 F (40 C) or higher lethargic, irritable or in pain Has signs or symptoms of dehydration, including dry mouth, crying without tears, little or no urination, unusual sleepiness, or unresponsiveness If you're an adult: a. Can't keep liquids down for 24 hours b. diarrhea for more than two days c. blood in your vomit or bowel movements d. temperature higher than 103 F (39.4 C) e. Have signs or symptoms of dehydration, including excessive thirst, dry mouth, little or no urination, severe weakness, dizziness on standing, or lightheadedness

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Diagnosis: Rotavirus is often diagnosed based on symptoms and a physical exam. A stool sample may be analyzed in a lab to confirm the diagnosis.

Treatment : There's no specific treatment for a rotavirus infection. Antibiotics and antivirals won't help a rotavirus infection. Usually, the infection resolves within three to seven days. a. Preventing dehydration is the biggest concern. To prevent dehydration while the virus runs its course, drink plenty of fluids. If your child has severe diarrhea, ask your doctor about offering an oral rehydration fluid such as Pedialyte or Enfalyte — especially if the diarrhea lasts longer than a few days. b. For children, a rehydration fluid can replace lost minerals more effectively than can water or other liquids. Severe dehydration may require intravenous fluids in the hospital. c. Anti-diarrheal medications aren't recommended for a rotavirus infection.

FUNGAL 1. Ergotism A condition that develops from ergotamines, substances produced due to fungal contamination of grains. A fungus (Claviceps purpurea) that contaminates rye and wheat produces substances (alkaloids) termed ergotamines.Ergotamines constrict blood vessels and cause the muscle of the uterus to contract. They have been much used and have been very useful for the treatment of migraine. They have also been used and misused as abortifacients (agents of abortion).

Causative Agent: Ergot alkaloids, parasitic fungus of the genus Claviceps.

Figure 53

Source: newsmedical.net

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Figure 54

Source: cdc.gov

Incubation Period : is highly variable from 2 weeks to 6 years (avg. 2-3 months).

Mode of Transmission:excessive ingestion (eating) of ergot fungus Vaccine: No vaccine Signs And Symptoms: a. Convulsive symptoms include painful seizures and spasms, b. diarrhea c. paresthesias, d. itching d.mental effects including mania or psychosis, headaches, nausea and vomiting Diagnosis: A duplex ultrasonography was the diagnostic imaging modality with serial ultrasound studies directing ongoing management and enabling close surveillance of the vascular status.

Treatment : Intravenous or intra-arterial infusion of sodium nitroprusside or nitroglycerine has proved the only reliably efficacious therapy. The best results have been obtained using nitroprusside.

2. Aflatoxin poisoning Are poisonous substances produced by certain kinds of fungi (moulds) that are found naturally all over the world; they can contaminate food crops and pose a serious health threat to humans and livestock.

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Causative agent: Aflatoxins belong to a group of toxins called mycotoxins, which are derived from fungi. In particular, aflatoxins are produced by the soil-born molds Aspergillus flavus and Aspergillus parasiticus that grow on the seeds and plants. At least 13 aflatoxins have been identified, including B1, B2, G1, G2, M1, and M2. The B aflatoxins fluoresce (illuminate into color) blue and the G aflatoxins fluoresce green in the presence of ultraviolet light. The M aflatoxins are present in milk products. Aflatoxin B1 is the most ubiquitous, most toxic, and most well studied of the aflatoxins.

Figure 55

Source: cdc.com

Figure 56

Sources: Cdbioscience.com

Incubation Period: variable Mode of Transmission: Oral, eating of contaminated food

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Vaccine: No vaccine Signs And symptoms : Adult humans have a higher tolerance to aflatoxin compared to kids. High-level exposure effects When food contaminated with this metabolite in large doses is ingested, patients will experience the following: a. Acute hepatic necrosis (Aflatoxicosis) Liver cirrhosis Carcinoma of the liver Acute liver failure due to bleeding Haemorrhaging b. Coma Death Vomiting Convulsions Oedema Digestion alterations and complication Abdominal pain Chronic/subclinical exposure effects There are no dramatic symptoms, such as vomiting and abdominal pain here. c. However, chronic exposure can increase the risk of developing gallbladder and liver cancers.

Effects of aflatoxin to children Exposure of the chemical to children can lead to the following: a.Stunted growth Delayed development b.Liver damage Diagnosis: Several methods including a. thin-layer chromatography (TLC) b. high-performance liquid chromatography (HPLC), c. mass spectroscopy d. enzyme-linked immune-sorbent assay (ELISA) e. and electrochemical immunosensor, among others, have been described for detecting and quantifying aflatoxins in foods.

Treatment: Note that aflatoxicosis is not contagious. When drugs and antibiotics are administered to a patient suffering from this poisoning, they can be of great help. Treatment might also depend on what symptoms the person in question is experiencing. In some cases, oxygen therapy, blood transfusions, fluid therapy, and many other procedures can be used to remedy the short-term effects associated with severe poisoning.

3. Mycotoxin poisoning Poisonous to both humans and animals. They cause a variety of adverse effects, including symptoms of acute poisoning. The long-term effects of chronic exposure to mycotoxins may include immune deficiencies and cancer.

Causative Agent : Dimorphic Paracoccidioides brasiliensis,

fungi,

which

include

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dermatitidis

and

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Figure 57

Source: shuttershock.com

Figure 58

Incubation Period: Approximately 15 minutes (range: 5-25 minutes), and median duration of illness was 4.5 hours (range: 10 minutes-8 hours).

Mode of Transmission: Exposure to mycotoxins can happen either directly by eating infected food or indirectly from animals that are fed contaminated feed, in particular from milk.

Vaccines:No vaccine Signs And Symptoms: a. gastrointestinal symptoms (nausea, vomiting and giddiness) b. followed by effects on the central nervous system (drowsiness, prolonged sleepiness, twitching, convulsions, blindness and paralysis).

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Diagnosis: a.

Specifically trichothecenes, aflatoxins, and ochratoxins, can be detected in human tissue and body fluids in patients who have been exposed to toxin producing molds in their environment.

Treatment: To minimize the health risk from mycotoxins, people are advised to: a. inspect whole grains (especially corn, sorghum, wheat, rice), dried figs and nuts such as peanuts, pistachio, almond, walnut, coconut, Brazil nuts and hazelnuts which are all regularly contaminated with aflatoxins for evidence of mould, and discard any that look mouldy, discoloured, or shrivelled; b. avoid damage of grains before and during drying, and in storage, as damaged grain is more prone to invasion of moulds and therefore mycotoxin contamination; c. buy grains and nuts as fresh as possible; d. make sure that foods are stored properly – kept free of insects, dry, and not too warm; e. do not keep foods for extended periods of time before being used; and f. ensure a diverse diet – this not only helps to reduce mycotoxins exposure, but also improves nutrition.

PARASITIC 1. Amoebiasis is a condition in which your gut (intestines) becomes infected.

Causative Agent: Entamoeba histolytica

Figure 59

Source: medicalnewstoday.com

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Incubation Period : highly variable and may be even as short as a few days or as long as several months or even a year.

Mode of Transmission: transmitted by the fecal-oral route, but it can also be transmitted indirectly through contact with dirty hands or objects as well as by anal-oral contact. Infection is spread through ingestion of the cyst form of the parasite, a semi-dormant and hardy structure found in feces.

Vaccines: No vaccines Signs and symptoms : a. loose stools, b. mild abdominal cramping, c. frequent, watery, and/or bloody stools with severe abdominal cramping (termed amoebic dysentery) may occur, d. flatulence, e. appetite loss, and. f. fatigue.

Diagnosis: a. microscopic examination of stool samples for the presence or absence of E. histolytica/E. dispar Treatment: a. Gastrointestinal amebiasis is treated with nitroimidazole drugs, which kill amoebas in the blood, in the wall of the intestine and in liver abscesses. These drugs include metronidazole (Flagyl) and tinidazole (Tindamax, Fasigyn)

2. Giardiasis Is an infection in your small intestine.

Causative agent: Giardia lamblia The flagellate protozoan Giardia intestinalis (previously known as G lamblia or G duodenalis) Figure 60

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Source: thescientist.com

Figure 61

Source: cdc.gov

Incubation Period : 1 to 14 days (average of 7 days) and usually lasts 1 to 3 weeks.

Mode of transmission : Anything that comes into contact with faeces from infected humans or animals can become contaminated with the Giardia parasite. Transmission occurs from person to person and animal to person via hand-to-mouth transfer of cysts from infected faeces or faecally contaminated surfaces.

Vaccine :No vaccine

Signs And Symptoms : a. Watery, sometimes foul-smelling diarrhea that may alternate with soft, greasy stools. b. Fatigue or malaise. c. Abdominal cramps and bloating. d. Gas or flatulence. e. Nausea. f. Weight loss.

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Diagnosis : a. Antigen testing of the stool. ... Giardia also can be diagnosed by examination of stool under the microscope for cysts or trophozoites; however, it takes three samples of stool to diagnose 90% of cases.

Treatment: a. Metronidazole (Flagyl). Metronidazole is the most commonly used antibiotic for giardia infection b. Tinidazole (Tindamax) c. Nitazoxanide (Alinia) 3. Ascariasis Is an infection of the small intestine Causative Agent: Ascaris lumbricoides, which is a species of roundworm. ... Ascariasis is the most common roundworm infection.

Figure 62

Source:wikipedia.com

Figure 63

Source: cdbioscience.com

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Incubation Period : usually takes 4–8 weeks.

Mode of Transmission: fecal-oral, such as by swallowing eggs in food or water contaminated by feces. fecal-oral.

Vaccines :No vaccines Signs And Symptoms : a. Abdominal discomfort b. Abdominal cramping c. Abdominal swelling (especially in children) d. Fever e. Coughing and/or wheezing f. Nausea g. Vomiting h. Passing roundworms and their eggs in the stool Diagnosis : a. stool sample and using a microscope to look for the presence of eggs. Some people notice infection when a worm is passed in their stool or is coughed up.

Treatment : a. Anthelmintic medications (drugs that rid the body of parasitic worms), such as albendazole and mebendazole, are the drugs of choice for treatment of Ascaris infections, regardless of the species of worm. Infections are generally treated for 1-3 days.

4. Hookworm Infection Is an infection of the intestines that can cause an itchy rash, respiratory and gastrointestinal problems, and eventually iron deficiency anemia due to ongoing loss of blood.

Causative agent: Helminth infection that is predominantly caused by the nematode parasites Necator americanus and Ancylostoma duodenale; organisms that play a lesser role include Ancylostoma ceylonicum, Ancylostoma braziliense, and Ancylostoma caninum.

Figure 64

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Source: cdbioscience.com

Figure 65

Source: wikipedia.org

Incubation Period : Approximately 1 to 2 weeks. The incubation period for intestinal hookworm disease varies with the number of parasites and can be a few weeks to many months.

Mode Of Transmission : Hookworm eggs are passed in the feces of an infected person. If an infected person defecates outside (near bushes, in a garden, or field) or if the feces from an infected person are used as fertilizer, eggs are deposited on soil. ... Hookworm infection is transmitted primarily by walking barefoot on contaminated soil.

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a. b. c. d. e. f. g. h.

abdominal pain. colic, or cramping and excessive crying in infants. intestinal cramps. nausea. a fever. blood in your stool. a loss of appetite. itchy rash.

Diagnosis : a. Identifying hookworm eggs in a sample of stool. ... During the 5 to 9 weeks between penetration of larvae and appearance of eggs in the stool, eosinophilia may be the only laboratory abnormality. b. Blood tests for anemia and iron deficiency are also done.

Treatment : a. Anthelmintic medications (drugs that rid the body of parasitic worms), such as albendazole and mebendazole, are the drugs of choice for treatment of hookworm infections. Infections are generally treated for 1-3 days.

5. Enterobiasis pinworm infection

Causative Agent : Oxyurus vermicularis, also known as pinworm or seatworm Figure 66

Source: cgc.gov

Figure 67 A Self-regulated Learning Module

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Sources: cdbioscience.com

Incubation Period : 1 to 2 months or longer for the adult gravid female to mature in the small intestine.

Mode Of Transmission : Transmitted by direct transfer of infected eggs by hand from the anus to the mouth of the same or another person. They can also be transmitted indirectly through bedding, clothing, food or other articles. Spread is facilitated by overcrowding.

Vaccine :No Vaccine Signs And Symptoms : Itching of the anal or vaginal area.

Insomnia, irritability and restlessness.

Intermittent abdominal pain and nausea.

Diagnosis : a.

Treatment : a.

Is made by identifying the worm or its eggs. Worms can sometimes be seen on the skin near the anus or on underclothing, pajamas, or sheets about 2 to 3 hours after falling asleep. Pinworm eggs can be collected and examined using the “tape test” as soon as the person wakes up.

Either mebendazole, pyrantel pamoate, or albendazole. Any of these drugs are given in one dose initially, and then another single dose of the same drug two weeks later. Pyrantel pamoate is available without prescription.

6. Trichuriasis - It is also known as whipworm infection, an infection by the parasitic worm.

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Causative agent : intestinal nematode Trichuris trichiura.

Figure 68

Source: Shuttershock.com

Figure 69

Source: shuttershock.com

Incubation Period : T. trichiura is unknown, however, immature eggs in soil under favorable conditions take about three weeks to mature: 15–30 days, 10 days minimum to mature before ideal ingestion by the human host.

Mode of Transmission : Whipworms have a direct developmental cycle whereby embryonated eggs are directly infective to the definitive host. Infections are transmitted by the faecal-oral route, involving the ingestion of eggs with contaminated food, water or soil.

Vaccine : Work is ongoing to develop a vaccine against the disease Signs And Symptoms : a. bloody diarrhea b. painful or frequent defecation

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c. d. e. f. g. h.

abdominal pain nausea vomiting headaches sudden and unexpected weight loss fecal incontinence, or the inability to control defecation

Diagnosis : a. Trichuriasis can be diagnosed when T. trichiura eggs are detected in stool examination. Eggs will appear barrel-shaped and embryonated, having bipolar plugs and a smooth shell. Rectal prolapse can be diagnosed easily using defecating proctogram and is one of many methods for imaging the parasitic infection.

Treatment : a. Anthelmintic medications (drugs that rid the body of parasitic worms), such as albendazole and mebendazole, are the drugs of choice for treatment. Infections are generally treated for 3 days. The recommended medications are effective.

Health care providers may decide to repeat a stool exam after treatment.

7. Strongylodiasis - Is a disease caused by a nematode, or a roundworm, in the genus Strongyloides.

Though there are over 40 species within this genus that can infect birds, reptiles, amphibians, livestock and other primates, Strongyloides stercoralis is the primary species that accounts for human disease.

Causative agent : Strongyloides stercoralis , The rhabditid nematode (roundworm) Strongyloides stercoralis is the major causative agent of strongyloidiasis in humans. Rarer human-infecting species of Strongyloides are the zoonotic S.

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Figure 70

Source: cdc.gov

Figure71

Source: cdbioscience.org

Incubation Period : Strongyloides is the only helminth to secrete larvae (and not eggs) in feces. Typically, larvae appear in feces approximately 1 month (about 28 days) after skin penetration, but the incubation period is unknown. As long as the patient is infected, which can be for several decades, the infection is communicable.

Mode Of Transmission : a. transmitted through direct penetration of human skin by infective larvae when in contact with soil; walking barefoot is therefore a major risk factor for acquiring the infection. Strongyloides spp.

Vaccine :No vaccine Signs and Symptoms : a. upper abdominal burning or pain. b. diarrhea, or alternating diarrhea and constipation. c. cough. d. rash.

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e. red hives near the anus. f. vomiting. g. weight loss.

Diagnosis : a. finding larvae in stool or small-bowel contents. b. occasionally sputum exam c. detection of antibodies in blood.

Treatment : The medicine of choice to treat strongyloidiasis is a single dose of the antiparasitic medication ivermectin (Stromectol). This drug works by killing the worms in your small intestine or two courses of albendazole (Albenza), to be taken 10 days apart.

8. Beef tapeworm Infection - Mild gastrointestinal upset or passage of a motile segment in the stool.

Causative Agent : a. Taeniasis intestinal tapeworm b. T. saginata tapeworm

Figure 72

Source: microbewki.com

Figure 73

Source: newsmedical.com

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Incubation Period : Eggs appear in the faeces 8–12 weeks after infection with the adult T. saginata tapeworm Mode Of Transmission : Humans are infected by ingestion of raw or undercooked beef infected with Cysticercus bovis, the larval stage of T. saginata. In humans, the adult tapeworm develops in the intestine over 2– 3 months.This occurs by direct transfer from the faeces of an infected person, or through ingestion of contaminated food or water.

Vaccine :No vaccine

Sign and Symptoms : a. eggs, larvae, or segments from the tapeworm in stools. b. abdominal pain c. vomiting d. nausea e. general weakness f. inflammation of the intestine g. diarrhea h. weight loss Diagnosis : The most visible sign of taeniasis is the active passing of proglottids (tapeworm segments) through the anus and in the feces. In rare cases, tapeworm segments become lodged in the appendix, or the bile and pancreatic ducts.

Treatment : Medications for the treatment of taeniasis include praziquantel (Biltricide) and albendazole (Albenza). Both drugs are anthelmintics, which means that they kill parasitic worms and their eggs.

9. Dwarf tapeworm Infection Infection is most common in children, in persons living in institutional settings, and in people who live in areas where sanitation and personal hygiene is inadequate.

Causative Agent : Hymenolepiasis is primarily caused by the cestode (tapeworm) species, Hymenolepis nana (the dwarf tapeworm, adults measuring 15 to 40 mm in length).

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Figure 74

Source: shuttershock.com

Figure 75

Source: shuttershock.com

Incubation Period : After four to five days, this infective larva will break free into the lumen of the small intestine and travel to the ileum where it will reattach itself to the intestinal mucosa. Within the next five days it will develop into a full adult worm. Besides humans, the house mouse is another possible definitive host.

Mode Of Transmission : One becomes infected by accidentally ingesting dwarf tapeworm eggs. This can happen by ingesting fecally contaminated foods or water, by touching your mouth with contaminated fingers, or by ingesting contaminated soil.

Vaccine :No vaccine Signs and symptoms :

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Most people who are infected do not have any symptoms. Those who have symptoms may experience a. Nausea b. Weakness c. loss of appetite d. diarrhea e. abdominal pain Diagnosis : Identifying dwarf tapeworm eggs in stool.

Treatment : A prescription drug called praziquantel is given. The medication causes the dwarf tapeworm to dissolve within the intestine. Praziquantel is generally well tolerated.

10. Fish Tapeworm Infection It is the largest parasite that infects humans.

Causative agent: fish tapeworm (Diphyllobothrium latum) Figure 76

Source: cdc.gov

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Figure 77

source: medicalnewstoday.net

Incubation Period :Unknown Mode of transmission : A fish tapeworm infection can occur when a person eats raw or undercooked fish that's contaminated with the parasite Diphyllobothrium latum. ... This type of tapeworm grows in hosts such as small organisms in the water and large mammals that eat raw fish. It's passed through the feces of animals.

Vaccine : No vaccine Signs And Symptoms : a. abdominal pain b. lack of appetite c. passing tapeworm parts in stool d. weight loss e. upset stomach Children who are infected may also experience: a. anal itching b. headache c. sleep disturbances d. Fish or Broad Tapeworm (D latum)

Diagnosis : a. blood test to identify the presence of a parasite. b. stool exam to check for parasites, worm segments, and eggs.

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Treatment : Fish tapeworm infections can be treated with a single dose of medication without any lasting problems. There are two main treatments for tapeworm infections: praziquantel (Biltricide) and niclosamide (Niclocide). *Praziquantel. This drug is used to treat different kinds of worm infections.

11. Pork Tapeworm Infection It is a parasitic disease -

Causativeagent: The Pacific broad tapeworm Adenocephalus pacificus (syn. Diphyllobothrium pacificum) is the causative agent of the third most common fish-borne cestodosis among humans.

Figure 78

Source: cdc.gov

Figure 79

source: shuttershock.net

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Incubation Period : The incubation period is 8–10 weeks for T. solium and 10–14 weeks for T. saginata.

Mode of Transmission : Solium taeniasis is acquired by humans through the ingestion of tapeworm larval cysts (cysticerci) in undercooked and infected pork. ... Humans can also become infected with T. solium eggs by ingesting contaminated food or water or because of poor hygiene via the fecaloral route.

Vaccine : No vaccine

Signs and Symptoms : a. Nausea. b. Weakness. c. Loss of appetite. d. Abdominal pain. e. Diarrhea. f. Dizziness. g. Salt craving. h. Weight loss and inadequate absorption of nutrients from food.

Diagnosis : Intestinal infection with adult T. solium worms can usually be diagnosed by microscopic examination of stool samples and identification of ova and/or proglottids.

Treatment : a. Adult worms can be eradicated with praziquantel. b. Treatment of symptomatic neurocysticercosis is complicated; it includes corticosteroids, antiseizure drugs, and, in some situations, albendazole or praziquantel. c. Surgery may be required.

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12. Rat tapeworm infection Is a parasitic disease Causative Agent : a. Hymenolepiasis is caused by two cestodes (tapeworm) species, Hymenolepis nana (the dwarf tapeworm, adults measuring 15 to 40 mm in length) and Hymenolepis diminuta (rat tapeworm, adults measuring 20 to 60 cm in length).

Figure 80

source: slideshare.net

Figure 81

Source: cdc.gov

Incubation Period : Unknown Mode of Transmission : A. This infection does not require an intermediate host and infection can occur directly from one infected person to another by fecal-oral transmission.

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B. Another less frequent zoonotic intestinal tapeworm infection is caused by H. diminuta, commonly known as the rat tapeworm, in which humans are incidental hosts.

Vaccine : No vaccine Signs and symptoms : a. Diarrhea. b. Gastrointestinal discomfort. c. Itchy anus. d. Poor appetite. e. Weakness Diagnosis :

a. Stool sample analysis. A laboratory uses microscopic identification techniques to check for eggs or tapeworm segments in your feces. o Because the eggs and segments are passed irregularly, the lab may need to collect two to three samples over a period of time to detect the parasite. Eggs are sometimes present at the anus, a piece of transparent adhesive tape pressed to the anus to collect eggs for microscopic identification. b. Blood test. For tissue-invasive infections, test your blood for antibodies your body may have produced to fight tapeworm infection. The presence of these antibodies indicates tapeworm infestation. c. Imaging exam. Certain types of imaging, such as CT or MRI scans, X-rays, or ultrasounds of cysts, may suggest invasive tapeworm Treatment : The most common treatment for tapeworm infection involves oral medications that are toxic to the adult tapeworm, including: a. Praziquantel (Biltricide) b. Albendazole (Albenza) c. Nitazoxanide (Alinia)

13. Schistosomiasis Also known as snail fever and bilharzia, is a disease caused by parasitic flatworms called schistosomes. The urinary tract or the intestines may be infected.

Causative agent : a. Hymenolepiasis is caused by two cestodes (tapeworm) species, Hymenolepis nana (the dwarf tapeworm, adults measuring 15 to 40 mm in length) and Hymenolepis diminuta (rat tapeworm, adults measuring 20 to 60 cm in length).

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Figure 82

Figure 83

Incubation Period : a. Usually 14-84 days; however, many people are asymptomatic and have subclinical disease during both acute and chronic stages of infection.

Mode Of Transmission : People become infected when larval forms of the parasite – released by freshwater snails – penetrate the skin during contact with infested water. Transmission occurs when people suffering from schistosomiasis contaminate freshwater sources with their excreta containing parasite eggs, which hatch in water.

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c. d. e. f. g. h.

Bloody diarrhea or blood in the stools Cough.

Malaise Headache Rash Body aches

Diagnosis : a. Detection of parasite eggs in stool or urine specimens. b. Antibodies and/or antigens detected in blood or urine samples are also indications of infection. c. Mansoni transmission areas, CCA (Circulating Cathodic Antigen) test can also be used.

Treatment : a. Schistosomiasis can usually be treated successfully with a short course of a medication called praziquantel, that kills the worms. Praziquantel is most effective once the worms have grown a bit, so treatment may be delayed until a few weeks after you were infected, or repeated again a few weeks after your first dose.

14. Fascioliasis It is a parasitic infection typically caused by Fasciola hepatica, which is also known as “the common liver fluke” or “the sheep liver fluke.”

-

Causative Agent : Fasciola hepatica and F. gigantica which require various species of Lymnaea, fresh water snails, as their intermediate hosts.

Figure 84

Source: cdc.gov

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Figure 85

Source: cdc.gov

Incubation Period : The period from ingestion of metacercariae to appearance of first symptom. This period can range from a few days to a few months. Acute phase: The period of migration of larvae from the peritoneal cavity to the biliary tree and liver. This period ranges from 2-4 months.

Mode of Transmission : Fascioliasis is infection with the liver fluke Fasciola hepatica, which is acquired by eating contaminated watercress or other water plants. Flukes are parasitic flatworms that infect various parts of the body (eg, blood vessels, gastrointestinal tract, lungs, liver) depending on the species. F. Vaccine : Fasciola antigens as vaccines against fascioliasis and schistosomiasis.

Signs and Symptoms : a. Fever b. Nausea c. a swollen liver d. skin rashes e. extreme abdominal pain.

Chronic phase. The chronic phase begins when the worms reach the bile ducts, where they mature and start producing eggs.

Diagnosis : a. recovery of the eggs in the patient's stool or from biliary tract drainage. b. ultrasound or computed tomography scans.

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Treatment : Triclabendazole, a benzimidazole compound active against immature and adult Fasciola parasites, is the drug of choice for treatment of fascioliasis. In February 2019, the U.S. Food and Drug Administration (FDA) approved triclabendazole for treatment of fascioliasis in patients at least 6 years of age.

15. Fasciolopsiasis It is an infection with the intestinal fluke Fasciolopsis buski, which is acquired by eating aquatic plants.

- Causative agent : a. Fasciolopsis buski, is the largest member of class Trematoda within the phylum Platyhelminthes.

Figure 86

Source: shutterstock.com

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Figure 87

Source: cdc.gov

Incubation Period : 1–2 months Mode of transmission : Fasciolopsiasis is infection with the intestinal fluke Fasciolopsis buski, which is acquired by eating aquatic plants. ... Human infection is acquired by eating aquatic plants (eg, water chestnuts) that bear infectious metacercariae (encysted stage).

Vaccine : No vaccine Signs and symptoms : abdominal pain and diarrhea can occur 1 or 2 months after infection. With heavy infections Fasciolopsis flukes can cause a. intestinal obstruction b. abdominal pain c. nausea d. Vomiting e. Fever f. Allergic reactions and swelling of the face and legs can also occur g. anemia may be present

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Diagnosis : The diagnosis is made by finding the flukes or their eggs in the feces or even in vomit.

Treatment : a. praziquantel 25 mg/kg orally 3 times a day for 1 day. b. Prevention involves not eating freshwater plants in areas where Fasciolopsis buski is endemic.

16. Clonorchiasis Is an infectious disease caused by the Chinese liver fluke, Clonorchis sinensis, and two related species. Clonorchiasis is a known risk factor for the development of cholangiocarcinoma, a neoplasm of the biliary system.

Causative Agent : a.

liver fluke Clonorchis sinensis.

Figure 88 Figure 89

Source: cdc.gov

Source : slideshare.com

Incubation Period : 1-2 months Most person with mild clonorchis sinensis infections are asymptomatic

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Mode of transmission : The eggs of Clonorchis are ingested by freshwater snails. After the eggs hatch, infected snails release microscopic larvae that then enter freshwater fish. People become infected by eating infected raw or undercooked fish containing the larvae.

Vaccine : No vaccine Signs And Symptoms : a. b. c. d. e. f.

Fever Chills epigastric pain tender hepatomegaly diarrhea mild jaundice.

Diagnosis : Diagnosis of clonorchiasis is by finding eggs in the feces or duodenal contents. The eggs are difficult to distinguish from those of Opisthorchis. Occasionally, the diagnosis is made by identifying adult flukes in surgical specimens or by doing percutaneous transhepatic cholangiography.

Treatment : a. Praziquantel 25 mg/kg orally 3 times a day for 2 days. b. Albendazole 10 mg/kg orally once a day for 7 days.

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Unit5: Check for Facts and Understanding Microbial Infection of the Digestive system Evaluate Answer the following questions?

1. Give 5 signs and symptoms of Shigellosis?

1.

2.

3.

4.

5.

2. Give 5 signs and symptoms of Typhoid fever?

6.

7.

8.

9.

10.

3. Give 5 signs and symptoms of Gastroenteritis?

11.

12.

13.

14.

15.

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Microbial Infection GENITOURINARY System

Male Figure 90

Source: slideshare.com

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Female Figure 91

Source: slideshare.com

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BACTERIAL 1.

GONORRHEA

✔ A bacterial infection that is transmitted by sexual contact. ✔ Gonorrhea is an infection caused by a sexually transmitted bacterium that infects both males and females. Gonorrhea most often affects the urethra, rectum or throat. In females, gonorrhea can also infect the cervix. ✔ Gonorrhea is most commonly spread during vaginal, oral or anal sex. But babies of infected mothers can be infected during childbirth. In babies, gonorrhea most commonly affects the eyes.

Causative agent: Gonorrhea is caused by the bacterium Neisseria gonorrhoeae. The gonorrhea bacteria are most often passed from one person to another during sexual contact, including oral, anal or vaginal intercourse.

Figure 91

Sources : cdc.gov

Figure 92

Source: cdc.gov

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Incubation period : The incubation period, the time from exposure to the bacteria until symptoms develop, is usually 2 to 5 days. But sometimes symptoms may not develop for up to 30 days. Gonorrhea may not cause symptoms until the infection has spread to other areas of the body.

Mode of transmission : Gonorrhea is passed from one person to another by contact with body fluids containing the bacteria during unprotected sexual intercourse.

Sign and symptoms : For women a. creased vaginal discharge b. Painful urination c. Vaginal bleeding between periods, such as after vaginal intercourse d. Abdominal or pelvic pain For men a. Painful urination b. Pus-like discharge from the tip of the penis c. Pain or swelling in one testicle Diagnosis : Urine or fluid from the infected area will be tested for gonorrhea. You may also be tested for other sexually transmitted infections (STIs) at the same time. Testing can be done with a Pap test.

As soon as you find out you have gonorrhea, be sure to let your sex partners know. Experts recommend that you notify everyone you've had sex with in the past 60 days. If you have not had sex in the past 60 days, contact the last person you had sex with.

Treatment : Antibiotics are used to treat gonorrhea.

Management : a. Use a condom every time you have sex. Latex and polyurethane condoms keep out the viruses and bacteria that cause STIs. b. Don't have more than one sex partner at a time. The safest sex is with one partner who has sex only with you. Every time you add a new sex partner, you are being exposed to all of the diseases that all of that person's partners may have.

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c. Be responsible. Don't have sex if you have symptoms of an infection or if you are being treated for an STI.

2.

Non-Gonorrheal Urethritis

It is an inflammation of the urethra that is not caused by gonorrheal infection.

Causative Agent : The most common bacterial cause of NGU is Chlamydia trachomatis, but it can also be caused

by Ureaplasma urealyticum, Haemophilus vaginalis, Mycoplasma genitalium, Mycoplasma hominis, Gardnerella vaginalis, Acinetobacter lwoffi, Ac. calcoclaceticus and E. coli.

Figure 93

Source: healthdirect.com

Figure 94

Source: cdc.gov

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Incubation Period : 7–21 days, compared to 2–5 days for gonorrhoea.

Mode of Transmission : During unprotected (without a condom) vaginal, anal or oral sex, organisms (tiny living cells) which cause inflammation can pass into the urethra (tube that carries urine out of the body).

NGU can occur in anyone who has a penis and is sexually active, although not all cases are caused by having sex.

Vaccine : no vaccines Signs and Symptoms : a. a white or cloudy discharge from the tip of your penis b. burning or painful sensation when you pee c. the tip of your penis feeling irritated and sore d. In women, NGU rarely causes any symptoms Diagnosis : a. swab test – a sample of fluid is taken from your urethra using a swab, which is like a small cotton bud. The swab may have a small plastic loop or cotton tip at the end; it's not painful, but can feel a little uncomfortable for a few seconds b. urine test – you'll be asked not to pee for at least 2 hours before providing a urine sample as this can help make the test results more reliable

Treatment : NGU is usually treated with antibiotics, which kill the germs that are causing the infection. The antibiotics most commonly used to treat NGU are doxycycline, which is taken twice a day for a week, or macrolide antibiotics, such as azithromycin, given as a single dose

3.

Syphilis

It is a bacterial infection usually spread by sexual contact. The disease starts as a painless sore — typically on your genitals, rectum or mouth. Syphilis spreads from person to person via skin or mucous membrane contact with these sores.

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Causative Agent : Bacterium Treponema pallidum subspecies pallidum.

Figure 95

source: microbewiki.com

Figure 96

Source: microbewiki.com

Incubation Period : average time between infection with syphilis and the start of the first symptom is 21 days, but can range from 10 to 90 days. Syphilis blood test results will be negative during this time.

Mode of Transmission : Syphilis is transmitted from person to person by direct contact with a syphilitic sore, known as a chancre. Chancres can occur on or around the external genitals, in the vagina, around the anus

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, or in the rectum, or in or around the mouth. Transmission of syphilis can occur during vaginal, anal, or oral sex.

Vaccine : No vaccine Signs And Symptoms : Syphilis develops in stages, and symptoms vary with each stage. But the stages may overlap, and symptoms don't always occur in the same order. You may be infected with syphilis and not notice any symptoms for years.

Primary syphilis The first sign of syphilis is a small sore, called a chancre (SHANG-kur). The sore appears at the spot where the bacteria entered your body. While most people infected with syphilis develop only one chancre, some people develop several of them.

The chancre usually develops about three weeks after exposure. Many people who have syphilis don't notice the chancre because it's usually painless, and it may be hidden within the vagina or rectum. The chancre will heal on its own within three to six weeks.

Secondary syphilis Within a few weeks of the original chancre healing, you may experience a rash that begins on your trunk but eventually covers your entire body — even the palms of your hands and the soles of your feet. This rash is usually not itchy and may be accompanied by wartlike sores in your mouth or genital area. Some people also experience hair loss, muscle aches, a fever, a sore throat and swollen lymph nodes. These signs and symptoms may disappear within a few weeks or repeatedly come and go for as long as a year.

Latent syphilis If you aren't treated for syphilis, the disease moves from the secondary stage to the hidden (latent) stage, when you have no symptoms. The latent stage can last for years. Signs and symptoms may never return, or the disease may progress to the third (tertiary) stage.

Tertiary syphilis About 15% to 30% of people infected with syphilis who don't get treatment will develop complications known as late (tertiary) syphilis. In the late stage, the disease may damage your brain, nerves, eyes, heart, blood vessels, liver, bones and joints. These problems may occur many years after the original, untreated infection.

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Neurosyphilis At any stage, syphilis can spread and, among other damage, cause damage to the brain and nervous system (neurosyphilis) and the eye (ocular syphilis).

Congenital syphilis Babies born to women who have syphilis can become infected through the placenta or during birth. Most newborns with congenital syphilis have no symptoms, although some experience a rash on the palms of their hands and the soles of their feet. Later signs and symptoms may include deafness, teeth deformities and saddle nose — where the bridge of the nose collapses.

However, babies born with syphilis can also be born too early, be born dead (stillborn) or die after birth.

Prevention a. Abstain or be monogamous. The only certain way to avoid syphilis is to not have (abstain from) sex. The next-best option is to have mutually monogamous sex in which both people have sex only with each other and neither partner is infected. b. Use a latex condom. c. Avoid recreational drugs. Misuse of alcohol or other drugs can inhibit your judgment and lead to unsafe sexual practices.

Diagnosis a. Blood. Blood tests can confirm the presence of antibodies that the body produces to fight infection. The antibodies to the syphilis-causing bacteria remain in your body for years, so the test can be used to determine a current or past infection. b. Cerebrospinal fluid. If it's suspected that you have nervous system complications of syphilis, your doctor may also suggest collecting a sample of cerebrospinal fluid through a procedure called a lumbar puncture (spinal tap).

Medication a. The preferred treatment at all stages is penicillin, an antibiotic medication that can kill the organism that causes syphilis. b. Penicillin is the only recommended treatment for pregnant women with syphilis.

4.

Vaginosis Bacterial vaginosis (BV) is an abnormal vaginal condition that is characterized by vaginal discharge and results from an overgrowth of atypical bacteria in the

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vagina. It is not a true bacterial infection but rather an imbalance of the bacteria that are normally present in the vagina.

Causative Agent : a. Gardnerella vaginalis b. Mobiluncus and Prevotella are the causative agents for bacterial vaginosis.

Figure 97

Figure 98

Source: healthdirect.com

Incubation Period : on average 4-7 days, with a range of 3-10 days) which may help distinguish it from other causes of genital ulcer disease.

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Mode of Transmission : BV is linked to an imbalance of “good” and “harmful” bacteria that are normally found in a woman's vagina. Having a new sex partner or multiple sex partners, as well as douching, can upset the balance of bacteria in the vagina.

Vaccine : Gynevac-a vaccine, containing lactobacillus for therapy and prevention of bacterial vaginosis and related diseases. ... Prophylactic immunization with Gynevac, a Hungarian patented vaccine with 5 inactivated strains of Lactobacilli might be a good alternative for prevention of the abovementioned complications.

Signs and Symptoms : a. b. c. d.

Thin, gray, white or green vaginal discharge Foul-smelling "fishy" vaginal odor Vaginal itching Burning during urination

Diagnosis : a. vaginal secretions under a microscope, looking for "clue cells," vaginal cells covered with bacteria that are a sign of bacterial vaginosis. b. Test your vaginal pH. Your doctor may check the acidity of your vagina by placing a pH test strip in your vagina.

Treatment : a. Metronidazole (Flagyl, Metrogel-Vaginal, others). This medicine may be taken as a pill by mouth (orally). Metronidazole is also available as a topical gel that you insert into your vagina. To reduce the risk of stomach upset, abdominal pain or nausea while using this medication, avoid alcohol during treatment and for at least one day after completing treatment — check the instructions on the product. b. Clindamycin (Cleocin, Clindesse, others). This medicine is available as a cream that you insert into your vagina. Clindamycin cream may weaken latex condoms during treatment and for at least three days after you stop using the cream. c. Tinidazole (Tindamax). This medication is taken orally. Tinidazole has the same potential for stomach upset and nausea as oral metronidazole does, so avoid alcohol during treatment and for at least three days after completing treatment.

VIRAL 1. Genital Warts are soft growths that appear on the genitals. They can cause pain, discomfort, and itching. Genital warts a sexually transmitted infection (STI) A Self-regulated Learning Module

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Causative agent : venereal warts or condylomata acuminata. They are caused by the human papillomavirus (HPV)

Figure 99

Source: cdc.gov.

Figure 100

Source: newsmedical.net

Incubation Period : 2 to 3 months, with a range of 1 to 20 months for genital warts. It can take up to 10 years for a high-risk HPV infection to develop into cancer.

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Mode of Transmission : Genital warts can spread from one person to another during vaginal or anal sex. The virus can be spread by skin to skin contact so it can be passed on by close genital contact. ... Warts can be easily spread from the genital area to the area around the anus without having anal sex.

Vaccine : The Gardasil vaccine has also received FDA approval for prevention of genital warts. The vaccine is recommended for optional use in boys and men. The vaccine is used in girls and boys and young adults ages 9 to 26 for prevention of genital warts caused by HPV types 6 and 11.

Signs and Symptoms : In women, genital warts can grow on the vulva, the walls of the vagina, the area between the external genitals and the anus, the anal canal, and the cervix. In men, they may occur on the tip or shaft of the penis, the scrotum, or the anus. Genital warts can also develop in the mouth or throat of a person who has had oral sexual contact with an infected person. signs and symptoms of genital warts include: a. b. c. d. e.

Small, flesh-colored, brown or pink swellings in your genital area A cauliflower-like shape caused by several warts close together Itching or discomfort in your genital area Bleeding with intercourse Genital warts can be so small and flat as to be invisible. Rarely, however, genital

Diagnosis : a. PAP test For women, it's important to have regular pelvic exams and Pap tests, which can help detect vaginal and cervical changes caused by genital warts or the early signs of cervical cancer.

- During a Pap test, your doctor uses a device called a speculum to hold open your vagina and see the passage between your vagina and your uterus (cervix). He or she will then use a long-handled tool to collect a small sample of cells from the cervix. The cells are examined with a microscope for abnormalities b. HPV test. only a few types of genital HPV have been linked to cervical cancer. A sample of cervical cells, taken during a Pap test, can be tested for these cancercausing HPV strains.

Treatment : Genital wart treatments that can be applied directly to your skin include:

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a. Imiquimod (Aldara, Zyclara). This cream appears to boost your immune system's ability to fight genital warts b. Podophyllin and podofilox (Condylox) c. Trichloroacetic acid d. Sinecatechins (Veregen)

2.

Herpes Is an infection caused by HSV (herpes simplex virus). This virus affects the external genitalia, anal region, mucosal surfaces, and skin in other parts of the body. Herpes is a long-term condition. However, many people never have symptoms even though they are carrying the virus.

Causative Agent : a. Herpes simplex virus type 2 (HSV-2) is the dominant primary causative agent in genital ulcerative infections. Since infections with HSV-2 usually are acquired through sexual contacts, antibodies are rarely found before the age of onset of sexual activity.

Figure 101

Source: newsmedicaltoday.com

Figure 102

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Incubation Period : When symptoms do occur, herpes lesions typically appear as one or more vesicles, or small blisters, on or around the genitals, rectum or mouth. The average incubation period for an initial herpes infection is 4 days (range, 2 to 12) after exposure.

Mode of Transmission : The herpes simplex virus, or herpes, is categorized into 2 types: herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2).HSV-1 is mainly transmitted by oral-to-oral contact to cause oral herpes (which can include symptoms known as “cold sores”), but can also cause genital herpes. HSV-2 is a sexually transmitted infection that causes genital herpes.

Vaccines : Developing the vaccine Signs and Symptoms : Most people infected with HSV don't know they have it because they don't have any signs or symptoms or because their signs and symptoms are so mild. Symptoms may begin about two to 12 days after exposure to the virus. they may include: A. Pain or itching. You may experience pain and tenderness in your genital area until the infection clears.

B. Small red bumps or tiny white blisters. These may appear a few days to a few weeks after infection.

C. Ulcers. These may form when blisters rupture and ooze or bleed. Ulcers may make it painful to urinate.

D. Scabs. Skin will crust over and form scabs as ulcers heal.

Diagnosis : a. Viral culture. This test involves taking a tissue sample or scraping of the sores for examination in the laboratory. b. Polymerase chain reaction (PCR) test. PCR is used to copy your DNA from a sample of your blood, tissue from a sore or spinal fluid. The DNA can then be tested to establish the presence of HSV and determine which type of HSV you have. c. Blood test. This test analyzes a sample of your blood for the presence of HSV antibodies to detect a past herpes infection.

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Treatment : There's no cure for genital herpes. Treatment with prescription antiviral medications may: a. b. c. d.

Help sores heal sooner during an initial outbreak Lessen the severity and duration of symptoms in recurrent outbreaks Reduce the frequency of recurrence Minimize the chance of transmitting the herpes virus to another

Antiviral medications used for genital herpes include: a. Acyclovir (Zovirax) b. Valacyclovir (Valtrex) Fungal

1. Candidiasis Is a fungal infection due to any type of Candida (a type of yeast). When it affects the mouth, in some countries it is commonly called thrush. Signs and symptoms include white patches on the tongue or other areas of the mouth and throat. Other symptoms may include soreness and problems swallowing.

Causative Agent : Yeast like fungus Candida albicans, is ubiquitous and needs only favourable conditions in the mouth and a weakened host to flourish.

Figure 103

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Figure 104

Source: cdc.gov

Incubation Period : The incubation period for oral thrush is about two to five days.

Mode of Transmission : Candida albicans is usually transmitted from mother to infant through childbirth, and remains as part of a normal human's microflora. The overgrowth of C. albicans leads to symptoms of disease, and it occurs when there are imbalances – for example, changes in the normal acidity of the vagina.

Vaccine : The fungal immunotherapeutic vaccine NDV-3A may be safe and highly effective when administered to women with recurrent vulvovaginal candidiasis (RVVC), according to a study recently published in Clinical Infectious Diseases.May 23, 2018

Signs And Symptoms : a. Itching and irritation in the vagina and vulva. b. A burning sensation, especially during intercourse or while urinating. c. Redness and swelling of the vulva. d. Vaginal pain and soreness. e. Vaginal rash. f. Thick, white, odor-free vaginal discharge with a cottage cheese appearance. g. Watery vaginal discharge.

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Diagnosis : a. Genitourinary candidiasis - A urinalysis should be performed; evidence of white blood cells (WBCs), red blood cells (RBCs), protein, and yeast cells is common; urine fungal cultures are useful. b. Gastrointestinal candidiasis - Endoscopy with or without biopsy.

Treatment : Mild or moderate genital Candida infections can be treated with a short course of an over-thecounter (OTC) or prescription antifungal cream, pill, or suppository. You could also be prescribed a single dose of an oral antifungal medication, such as fluconazole.

2. Tineacruris Jock itch (tinea cruris) is a fungal infection that causes a red and itchy rash in warm and moist areas of the body. The rash often affects the groin and inner thighs and may be shaped like a ring. Jock itch gets its name because it's common in athletes. It's also common in people who sweat a lot or who are overweight.

Causative Agent : Trichophyton rubrum and Epidermophyton floccosum; mentagrophytes and Trichophyton verrucosum are involved.

less

commonly

Trichophyton

Figure 105

Source: medicalnewstoday.com

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Figure 106

Source: newsmedical.net

Incubation period : The incubation period varies depending on the type of ringworm. The incubation period for Tinea capitis is 10 to 14 days, Tinea corporis and Tinea cruris is 4 to 10 days, and the incubation for Tinea pedis is unknown.

Mode of Transmission : Tinea cruris is a contagious infection transmitted by fomites, such as contaminated towels or hotel bedroom sheets, or by autoinoculation from a reservoir on the hands or feet (tinea manuum, tinea pedis, tinea unguium).

Mode of Transmission : Tinea cruris is a contagious infection transmitted by fomites, such as contaminated towels or hotel bedroom sheets, or by autoinoculation from a reservoir on the hands or feet (tinea manuum, tinea pedis, tinea unguium).

Vaccine : No vaccine Signs and Symptoms : a. redness b. persistent itching c. burning sensation d. flaking, peeling, or cracking skin e. rash that gets worse with exercise or activity f. changes in skin color g. rash that doesn't improve or worsens, or spreads with over-the-counter hydrocortisone (anti-itch) cream

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Diagnosis : a. skin scrapings or samples from the infected area for study under a microscope.

Treatment : A. For mild jock itch, your doctor may suggest first using an over-the-counter antifungal ointment, lotion, powder or spray. Apply the medication as your doctor recommends for one to two weeks even if the rash clears up quickly.

B. If you also have athlete's foot, it's usually treated at the same time as jock itch to reduce the risk of the rash coming back. Severe jock itch or a rash that doesn't improve with over-thecounter medicine may need prescription-strength creams, ointments or pills.

PARASITIC 1. Trichomoniasis - is a very common sexually transmitted disease (STD). It is caused by infection with a protozoan parasite called Trichomonas vaginalis.

Causative Agent : a. Trichomonas vaginalis Figure 107

Source:geneproof.com

Figure 108

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Incubation Period : Trichomoniasis is caused by a one-celled protozoan, a type of tiny parasite that travels between people during sexual intercourse. The incubation period between exposure and infection is unknown, but it's thought to range from five to 28 days.

Mode of transmission : Trichomonas vaginalis is typically transmitted through vaginal, oral, or anal sex with an infected individual. It can also be passed from a mother to her baby at birth, as evidenced by the discovery of the parasite in the newborn's lungs.

Vaccine : No vaccine Signs And Symptoms : a. vaginal discharge, which can be white, gray, yellow, or green, and usually frothy with an unpleasant smell. b. vaginal spotting or bleeding. c. genital burning or itching. d. genital redness or swelling. e. frequent urge to urinate. f. pain during urination or sexual intercourse.

Diagnosis: a. The diagnosis of trichomoniasis can be confirmed by looking at a sample of vaginal fluid for women or urine for men under a microscope. Growing a culture used to be the way to diagnose trichomoniasis. b. rapid antigen tests c. nucleic acid amplification

Treatment : The most common treatment for trichomoniasis, even for pregnant women, is to swallow one megadose of either metronidazole (Flagyl) or tinidazole (Tindamax).

2. E. Histolytica Infection - Entamoeba histolytica Infection. Amebiasis is a disease caused by the parasite Entamoeba histolytica. It can affect anyone, although it is more common in people who live in tropical areas with poor sanitary conditions.

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Causative agent : a.

Entamoeba histolytica, which has an infective cyst stage and a pathogenic and motile trophozoite stage. The clinical presentation can vary from an asymptomatic carrier state to fulminant colitis and colonic perforation.

Figure 108

Source: new-medical.net

Figure 109

Source: wikipedia.org

Incubation Period : E histolytica infection is commonly 2-4 weeks but may range from a few days to years. The clinical spectrum of amebiasis ranges from asymptomatic infection to fulminant colitis and peritonitis to extraintestinal amebiasis, the most common form of which is amebic liver abscess.

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Mode Of transmission : Transmission can occur through fecal-oral route (ingestion of food and water, contaminated with feces containing E. histolytica cysts)

Vaccine : No Vaccine Signs and Symptoms : The symptoms are often quite mild and can include a. loose feces (poop) b. stomach pain c. stomach cramping. d. Amebic dysentery is a severe form of amebiasis associated with stomach pain, bloody stools (poop), and fever. Rarely, E. histolytica invades the liver and forms an abscess (a collection of pus).

Diagnosis : a. A single stool examination has a low sensitivity of detecting the parasite b. The best diagnostic method is detection of E. histolytica antigen or DNA in stool.

Treatment : a. Metronidazole, tinidazole and ornidazole were compared in patients treated for Entamoeba histolytica or Giardia lamblia intestinal infections.

3. Pediculosis Is an infestation of the hairy parts of the body or clothing with the eggs, larvae or adults of lice. The crawling stages of this insect feed on human blood, which can result in severe itching. Head lice are usually located on the scalp, crab lice in the pubic area and body lice along seams of clothing.

Causative Agent : Pediculosis is infestation with the human head-and-body louse, Pediculus humanus. There are two subspecies, the head louse (P. h. capitis) and the body louse

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Figure 110

Source: shuttershock.com

Figure 111

Source:news-medical.net

Mode of transmission : Transmitted through direct head-to-head contact with a person with head lice. Nymphal and adult lice usually die within 24 hours of being stranded away from the head. There is no significant risk of transmission from the environment.

Vaccine :No vaccine Signs and Symptoms : a. A ticklish feeling on the pubic area b. An itchy (the result of an allergic reaction to the bug's saliva). c. Small red bumps on the scalp, neck and shoulders and genital area d. The presence of lice on the pubic hair e. The presence of nits (lice eggs) on shafts of hair. f. Difficulty sleeping, which can lead to irritability.

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Diagnosis : The diagnosis of pediculosis is best made by finding a live nymph or adult louse on the scalp or in the hair or pubic hair of a person. Finding numerous nits within 6 mm of the scalp is highly suggestive of active infestation.

Treatment : a. Permethrin 1% It was introduced for the first time in the year 1986 as a scheduled topical agent b. Malathion 0.5% c. Lindane 1% d. Permethrin 5% (Permite) e. Crotamiton 10% f. Oral ivermectin g. Sulfamethoxazole-trimethoprim h. Benzyl alcohol 5%

4. Scabies is a skin infestation caused by a mite known as the Sarcoptes scabiei. Untreated, these microscopic mites can live on your skin for months. They reproduce on the surface of your skin and then burrow into it and lay eggs. This causes an itchy, red rash to form on the skin.

Causative Agent : a. Mite Sarcoptes scabiei

Figure 112

Source: wikipedia.org

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Figure 113

Source: cdbioscience.com

Incubation Period : It may take 2–6 weeks before itching occurs in a person not previously exposed to scabies.

Symptoms develop much more quickly if a person is re-exposed, often within 1–4 days. The incubation period may be shorter if infestation is acquired from a person with crusted (Norwegian) scabies.

Mode of transmission : Scabies is transmitted: primarily via skin contact with an infected person (e.g. sex partners, children playing, healthcare providers) less commonly via contact with towels, bedclothes and undergarments, if these have been contaminated by infested people within the previous 4–5 days Vaccine :No Vaccine Signs and symptoms : a. Itching, often severe and usually worse at night. b. Thin, irregular burrow tracks made up of tiny blisters or bumps on your skin.

Diagnosis : To diagnose scabies, your doctor examines your skin, looking for signs of mites, including the characteristic burrows. When your doctor locates a mite burrow, he or she may take a scraping from that area of your skin to examine under a microscope.

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Treatment : The 2 most widely used treatments for scabies are permethrin cream and malathion lotion (brand name Derbac M). Both medications contain insecticides that kill the scabies mite.

Permethrin 5% cream is usually recommended as the first treatment. Malathion 0.5% lotion is used if permethrin is ineffective.

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Unit 5: Check for facts and Understanding Microbial Infection of the Genitourinary System

EVALUATE Multiple choices: Write the letter of your choice in your answer beside the number.

1.

2.

3.

4.

What is the characteristic of a N. gonorrhea? a.

Gram – negative

b.

Diplococcus

c.

Affects the hosts columnar or cuboidal epithelium

d.

All of the above

What is the mode of transmission of gonorrhea? a.

Sexual contact

b.

From mother to baby at birth

c.

Oral sex

d.

All of the above

What is the causative agent of Syphilis? a.

Bacterium Treponema pallidum subspecies pallidum.

b.

Chlamydia trachomatis

c.

Neisseria gonorrhoeae

d.

None of the above

What is the mode of transmission of Herpes? a.

Touching the hands of infected person

b.

Airborne, sneezing and talking

c.

None of the above

d.

All of the above

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5.

Which of the following signs and symptoms of Herpes? a.

Small red bumps or tiny white blisters. These may appear a few days to a few weeks after infection. b.

Ulcers. These may form when blisters rupture and ooze or bleed. Ulcers may make it painful to urinate.

6.

7.

8.

c.

Scabs. Skin will crust over and form scabs as ulcers heal

d.

All of the above

What is the causative agent of Candidiasis? a.

Candida albicans

b.

Treponema pallidum

c.

All of the above

d.

None of the Above

What is the incubation of Candidiasis? a.

The incubation period for oral thrush is about two to five days.

b.

3 weeks

c.

2 weeks

d.

None of the above

Which of the following is the treatment of Candidiasis? a.

7 days antibiotics

b. short course of an over-the-counter (OTC) or prescription antifungal cream, pill, or suppository

9.

c.

All of the above

d.

D. None of the above

What is the mode of transmission of gonorrhea? a. Passed from one person to another by contact with body fluids containing the bacteria during unprotected sexual intercourse. b.

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10..

c.

Skin to skin

d.

All of the above

Which of the following are the signs and symptoms of trichomoniasis? a. vaginal spotting or bleeding b. genital burning or itching c. genital redness or swelling d. All of the above

11.

What is the mode of transmission of Trichomoniasis? a. transmitted through vaginal, oral, or anal sex with an infected individual

b. It can also be passed from a mother to her baby at birth, as evidenced by the discovery of the parasite in the newborn's lungs. c. All of the above d.

12.

None of the above Which of the following are the signs and symptoms of Pediculosis Except?

a. A ticklish feeling on the pubic area b. An itchy sensation on the affected area (the result of an allergic reaction to the bug's saliva). c. Small red bumps on the scalp, neck and shoulders and genital area d.

13.

None of the above What is the causative agent of Scabies

a.

Ticks

b.

Mite Sarcoptes scabiei

c.

Candida Albicans

d.

None of the above

14.

Which of the following are the signs and symptoms of scabies? a.

Itching, often severe and usually worse at night.

b.

Thin, irregular burrow tracks made up of tiny blisters or bumps on your skin.

c.

All of the above

d.

A only

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Time to think ???

What happens when microorganism enters the body? and what is the body doing in the fight of infection?

ENGAGE Open discussion on COVID 19

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Microbial infection Central Nervous System

Figure 114

Source: readbiology.com

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BACTERIAL

1. Meningitis It is an inflammation (swelling) of the protective membranes covering the brain and spinal cord.

A bacterial or viral infection of the fluid surrounding the brain and spinal cord usually causes the swelling. However, injuries, cancer, certain drugs, and other types of infections also can cause meningitis.

-

Causative Agent : a. Meningococcus (Neisseria meningitidis) is the commonest causative in adolescents and middle aged individuals, while Streptococcus pneumonia is again the most common causative bacterial organism causing meningitis in the elderly. Mycobacterium is also a causative of meningitis.

Figure 115

Source: microbewiki.com

Figure 116

Source: slideplayer.com

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Incubation Period : between two and 10 days.

Mode of transmission : The bacteria are transmitted from person-to-person through droplets of respiratory or throat secretions from carriers. Smoking, close and prolonged contact – such as kissing, sneezing or coughing on someone, or living in close quarters with a carrier – facilitates the spread of the disease.

Vaccine : Three meningococcal vaccines are available: a. Meningococcal polysaccharide vaccine (MPSV4), sold as Menomune. b. Meningococcal conjugate vaccine (MCV4), sold as Menactra, MenHibrix, and c. Menveo. Serogroup B meningococcal vaccine, sold as Trumenba and Bexsero.

Signs and symptoms: a. nausea and vomiting b. fever c. headache and a stiff neck d. muscle pain e. sensitivity to light f. confusion g. cold hands or feet and mottled skin

Diagnosis : Spinal tap to collect cerebrospinal fluid (CSF). In people with meningitis, the CSF often shows a low sugar (glucose) level along with an increased white blood cell count and increased protein

Treatment : a. Commonly used meningitis treatments include a class of antibiotics called cephalosporins, especially Claforan (cefotaxime) and Rocephin (ceftriaxone). b. Various penicillin-type antibiotics, aminoglycoside drugs such as gentamicin, and others, are also used.

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2.

Listeriosis

is a serious infection caused by the germ Listeria monocytogenes. People usually become ill with listeriosis after eating contaminated food. The disease primarily affects pregnant women, newborns, older adults, and people with weakened immune systems.

Causative Agent : The major human pathogen in the genus Listeria is L. monocytogenes. It is usually the causative agent of the relatively rare bacterial disease listeriosis, an infection caused by eating food contaminated with the bacteria.

Figure 117

Source:microbewiki.com

Incubation Period : Once infected, it can take from 1 to over 90 days for illness to develop. The average incubation period is about 30 days.

Mode of Transmission : Can be spread to people by several different methods. Eating food contaminated with the bacteria, such as through raw (unpasteurized) milk or contaminated vegetables, is often a source for cases. The bacteria may be passed from mother to fetus during pregnancy or directly to the newborn at the time of birth.

Vaccine : no vaccine Signs and Symptoms : a. Headache. b. Stiff neck.

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c. Confusion or changes in alertness. d. Loss of balance. e. Convulsions

Diagnosis : Listeriosis is usually diagnosed when a bacterial culture (a type of laboratory test) grows Listeria monocytogenes from a body tissue or fluid, such as blood, spinal fluid, or the placenta.

Treatment : Treatment of listeria infection varies, depending on the severity of the signs and symptoms.

Most people with mild symptoms require no treatment. More-serious infections can be treated with antibiotics. During pregnancy, prompt antibiotic treatment might help keep the infection from affecting the baby.

3.

Tetanus Also called lockjaw, is a serious infection caused by Clostridium tetani. This bacterium produces a toxin that affects the brain and nervous system, leading to stiffness in the muscles. If Clostridium tetani spores are deposited in a wound, the neurotoxin interferes with nerves that control muscle movement.

Causative Agent : The genomic sequence of Clostridium tetani, the cause of tetanus in humans and vertebrate animals, has been elucidated. This anaerobic spore-forming bacterium, found in soil, dust, and intestinal tracts of animals, produces a poisonous toxin, the tetanus toxin, which causes paralysis.

Figure 118

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Incubation Period : The average incubation period is seven to 10 days. Common signs and symptoms of tetanus include: Spasms and stiffness in your jaw muscles (trismus) Mode of Transmission : Tetanus is not transmitted from person to person. A person usually becomes infected with tetanus when dirt enters a wound or cut. Tetanus germs are likely to grow in deep puncture wounds caused by dirty nails, knives, tools, wood splinters, and animal bites.

Vaccines : There are vaccines that include protection against tetanus: a.

The DTaP vaccine protects young children from diphtheria, tetanus, and whooping cough. b. The DT vaccine protects young children from diphtheria and tetanus. c. The Tdap vaccine protects preteens, teens, and adults from tetanus, diphtheria, and whooping cough.

Signs And Symptoms : a. Stiffness of the neck, jaw, and other muscles, often accompanied by a sneering, grinning expression. b. Difficulty swallowing. c. Fever. d. Sweating. e. Uncontrollable spasms of the jaw, called lockjaw, and neck muscles. f. Painful, involuntary contraction of other muscles.

Diagnosis : a.

Doctors diagnose tetanus based on a physical exam, medical and immunization history, and the signs and symptoms of muscle spasms, stiffness and pain.

Laboratory tests generally aren't helpful for diagnosing tetanus.

Wound care It's essential to clean the wound to prevent the growth of tetanus spores. This involves removing dirt, foreign objects and dead tissue from the wound.

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Medications a. Antitoxin. Your doctor may give you a tetanus antitoxin, such as tetanus immune globulin. However, the antitoxin can neutralize only toxin that hasn't yet bonded to nerve tissue. b. Antibiotics. Your doctor may also give you antibiotics, either orally or by injection, to fight tetanus bacteria. c. Vaccine. All people with tetanus should receive the tetanus vaccine as soon as they're diagnosed with the condition. d. Sedatives. Doctors generally use powerful sedatives to control muscle spasms. e. Other drugs. Other medications, such as magnesium sulfate and certain beta blockers, might be used to regulate involuntary muscle activity, such as your heartbeat and breathing. Morphine might be used for this purpose as well as sedation.

- Supportive therapies - If you have a severe tetanus infection, you'll often need to stay in an intensive care setting. Since sedatives can inhibit breathing, you might temporarily need a ventilator.

VIRAL

1. Poliomyelitis Polio, or poliomyelitis, is a disabling and life-threatening disease caused by the poliovirus. The virus spreads from person to person and can infect a person's spinal cord, causing paralysis (can't move parts of the body).

Causative Agent : Poliovirus, the causative agent of polio (also known as poliomyelitis), is a serotype of the species Enterovirus C, in the family of Picornaviridae.

Incubation Period : The incubation period for nonparalytic poliomyelitis is 3-6 days. For the onset of paralysis in paralytic poliomyelitis, the incubation period usually is 7 to 21 days. The response to poliovirus infection is highly variable and has been categorized on the basis of the severity of clinical presentation.

Mode of Transmission : Wild poliovirus is spread through faeces and saliva. It is primarily transmitted through faecal– oral spread and is an important consideration where sanitation is poor. 'Live' oral polio vaccine (OPV) virus can be shed in the faeces for 6 weeks and may lead to infection in unvaccinated contacts.

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Vaccine : a. Inactivated polio vaccine (IPV) is the only polio vaccine that has been given in the United States since 2000. IPV is given by shot in the leg or arm, depending on the patient's age. b. Oral polio vaccine (OPV) is used in other countries. CDC recommends that children get four doses of polio vaccine.

Signs and Symptoms : a. Fever b. Sore throat c. Headache d. Vomiting e. Fatigue f. Back pain or stiffness g. Neck pain or stiffness h. Pain or stiffness in the arms or legs

Diagnosis : Doctors often recognize polio by symptoms, such as neck and back stiffness, abnormal reflexes, and difficulty swallowing and breathing.To confirm the diagnosis, a sample of throat secretions, stool or a colorless fluid that surrounds your brain and spinal cord (cerebrospinal fluid) is checked for poliovirus .

Treatment : Once the virus that causes polio has infected a person, there is no treatment that will cure polio.

Early diagnosis and supportive treatments such as bed rest, pain control, good nutrition, and physical therapy to prevent deformities from occurring over time can help reduce the long-term symptoms due to muscle loss.

2. Rabies Is a viral disease that causes inflammation of the brain in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure.

Causative Agent : Rabies virus (RV), a negative-stranded RNA virus of the rhabdovirus family.

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Figure 119

Source:meduwed.com

Incubation Period : Rabies in humans is generally 20–60 days. However, fulminant disease can become symptomatic within 5–6 days; more worrisome, in 1%–3% of cases the incubation period is >6 months. Confirmed rabies has occurred as long as 7 years after exposure, but the reasons for this long latency are unknown.

Mode of transmission : The virus is spread through the saliva of infected animals. Infected animals can spread the virus by biting another animal or a person. In rare cases, rabies can be spread when infected saliva gets into an open wound or the mucous membranes, such as the mouth or eyes.

Vaccine : Rabies vaccine can prevent rabies if given to a person after they have had an exposure.The person should also get another shot called rabies immune globulin (RIG). A person who has been previously vaccinated should get 2 doses of rabies vaccine and does not need Rabies Immune Globulin.

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Signs and symptoms : a. irritability or aggressiveness. b. excessive movements or agitation. c. confusion, bizarre or strange thoughts, or hallucinations. d. muscle spasms and unusual postures. e. seizures (convulsions) f. weakness or paralysis (when a person cannot move some part of the body)

Diagnosis : In animals, rabies is diagnosed using the direct fluorescent antibody (DFA) test, which looks for the presence of rabies virus antigens in brain tissue. In humans, several tests are required.

Treatment : A fast-acting shot (rabies immune globulin) to prevent the virus from infecting you.A series of rabies vaccinations to help your body learn to identify and fight the rabies virus.

3. Encephalitis Is inflammation of the brain. There are several causes, but the most common is viral infection. Encephalitis often causes only mild flu-like signs and symptoms — such as a fever or headache — or no symptoms at all.

Causative agent : Encephalitis is most often due to a virus, such as: herpes simplex viruses, which cause cold sores and genital herpes (this is the most common cause of encephalitis) the varicella zoster virus, which causes chickenpox and shingles. measles, mumps and rubella viruses.

Incubation Period : The incubation period for Eastern equine encephalitis virus (EEEV) disease (the time from infected mosquito bite to onset of illness) ranges from 4 to 10 days.

Mode of Transmission : Some of the modes of viral transmission include: coughs or sneezes from an infected person that release airborne viruses, which are then inhaled by others. ... there is evidence to suggest that some cases of viral encephalitis are caused by a dormant viral infection (such as herpes simplex virus) becoming active again.

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Vaccine : Inactivated Vero cell culture-derived Japanese encephalitis (JE) vaccine (manufactured as IXIARO) is the only JE vaccine licensed and available in the United States. This vaccine was approved in March 2009 for use in people aged 17 years and older and in May 2013 for use in children 2 months through 16 years of age Signs And Symptoms : a. Headache b. Fever c. Aches in muscles or joints d. Fatigue or weakness e. Sometimes the signs and symptoms are more severe, and might include: f. Confusion, agitation or hallucinations g. Seizures h. Loss of sensation or paralysis in certain areas of the face or body i. Muscle weakness j. Problems with speech or hearing k. Loss of consciousness In infants and young children, signs and symptoms might also include: a. b. c. d. e.

Bulging in the soft spots (fontanels) of an infant's skull Nausea and vomiting Body stiffness Poor feeding or not waking for a feeding Irritability

Diagnosis : a. Samples of blood, urine or excretions from the back of the throat can be tested for viruses or other infectious agents. b. Electroencephalogram (EEG). Electrodes affixed to your scalp record the brain's electrical activity. Certain abnormal patterns may indicate a diagnosis of encephalitis. c. Brain imaging. MRI or CT images can reveal any swelling of the brain or another condition that might be causing your symptoms, such as a tumor. d. Spinal tap (lumbar puncture). A needle inserted into your lower back removes cerebrospinal fluid (CSF), the protective fluid that surrounds the brain and spinal column. Changes in this fluid can indicate infection and inflammation in the brain.

Sometimes samples of CSF can be tested to identify the virus or other infectious agent.

Treatment a. Bed rest b. Plenty of fluids

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c. Anti-inflammatory drugs — such as acetaminophen (Tylenol, others), ibuprofen (Advil, Motrin IB, others) and naproxen sodium (Aleve) — to relieve headaches and fever d. Antiviral drugs e. Encephalitis caused by certain viruses usually requires antiviral treatment.

Antiviral medications commonly used to treat encephalitis include: a. Acyclovir (Zovirax) b. Ganciclovir (Cytovene) c. Foscarnet (Foscavir)

FUNGAL

1. Cryptococcus Meningitis is a serious infection of the brain and spinal column that can occur in people living with HIV. It is caused by a fungus called Cryptococcus neoformans. This fungus is very common in the environment and can be found in soil and in bird droppings.

Causative agent : Cryptococcus neoformans is the causative agent for the most common fungal meningitis.

Figure 120

Source: health;ine.com

Incubation Period : Incubation period is shorter than C. neoformans, with a median time of 6 months (extremes 2 weeks-2 years)

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Mode Of Transmission : Fungal meningitis is not spread from person to person. Instead, an individual acquires cryptococcal meningitis when they inhale soil particles contaminated by bird droppings. The fungus first infects the body, and then the infection spreads to the central nervous system, resulting in cryptococcal meningitis.

Vaccine : No vaccine, developing Signs And Symptoms : a. headache. b. nausea. c. vomiting. d. mental changes, including confusion, hallucinations, and personality changes. e. lethargy.

Diagnosis : There are two ways to diagnose cryptococcal meningitis. a. The first involves looking for the fungus in the bloodstream through a simple blood t b. Test the cerebrospinal fluid (CSF). In this case, a lumbar puncture (spinal tap) must be done.

Treatment : Antifungal drugs to treat cryptococcal meningitis. Common antifungal medications used to treat it include: amphotericin B. fluconazole.

PARASITIC

1.

Acanthamoeba - It is a microscopic, free-living ameba, or amoeba* (single-celled living organism), that can cause rare, but severe infections of the eye, skin, and central nervous system.

The ameba is found worldwide in the environment in water and soil.

Causative Agent : Acanthamoeba keratitis is an eye infection caused by microscopic amoeba.

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Figure 121

Source: endmyopia.org

Incubation Period : The incubation period varies based on the initial inoculum but is hypothesized to be from several days to several weeks.

Mode of Transmission : a. includes inhalation of cysts and trophozoites carried by the wind through the respiratory tract. b. Improper contact lens-care practices c. Direct skin contact by traumatic injection or entry through preexisting wounds or lesions.

Vaccine : No Vaccine Signs And Symptoms : a. Eye pain. b. Eye redness. c. Blurred vision. d. Sensitivity to light. e. Sensation of something in the eye. f. Excessive tearing.

Diagnosis : The infection is usually diagnosed by an eye specialist based on symptoms, growth of the ameba from a scraping of the eye, and/or seeing the ameba by a process called confocal microscopy.

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Treatment : Many authorities recommend a combination of chlorohexidine (0.02%) and polyhexamethylene biguanide (PHMB, 0.02%) for treating both the trophozoites and cysts. These topical antimicrobials are administered every hour immediately after corneal debridement or for the first several days of therapy.

2.

Naegleria - It is an ameba (single-celled living organism) commonly found in warm freshwater (for example, lakes, rivers, and hot springs) and soil. Only one species (type) of Naegleria infects people: Naegleria fowleri.

-

Causative Agent :

-

The free-living amoeba flagellate Naegleria fowleri is the causative agent of primary amoebic meningoencephalitis (PAM)

Figure 122

Sources: Cdbioscience.com

Incubation Period : The period between initial contact with the pathogenic N. fowleri and the onset of clinical signs and symptoms varies from 2-3 days to as long as 7-15 days. Once symptomatic, however, progression of PAM is rapid and often fatal.

Mode Of Transmission : Naegleria fowleri infects people when water containing the ameba enters the body through the nose. This typically occurs when people go swimming or diving in warm freshwater places, like lakes and rivers. You cannot be infected with Naegleria fowleri by drinking contaminated water.

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Vaccine :No vaccine Signs And Symptoms : a. A change in the sense of smell or taste. b. Fever c. Sudden, severe headache. d. Stiff neck e. Sensitivity to light f. Nausea and vomiting g. Confusion h. Loss of balance

Diagnosis : PAM and Naegleria fowleri infection can be diagnosed in the laboratory by detecting a. a. Naegleria fowleri organisms in cerebrospinal fluid (CSF), biopsy, or tissue specimens, b. Naegleria fowleri nucleic acid in CSF, biopsy, or tissue specimens. c. Naegleria fowleri antigen in CSF, biopsy, or tissue specimens.

Treatment : The primary treatment for naegleria infection is an antifungal drug, amphotericin B — usually injected into a vein (intravenously) or into the space around your spinal cord to kill the amoebas.

An investigational drug called miltefosine (Impavido) is now available for emergency treatment of naegleria infection.

4. Cerebral Malaria - is the most severe neurological complication of infection with Plasmodium falciparum malaria. It is a clinical syndrome characterized by coma and asexual forms of the parasite on peripheral blood smears.

Causative Agent : Plasmodium species. P. falciparum, the major causative agent of human CM, accounts annually for approximately one million deaths of children in Sub-Saharan Africa alone.

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Figure 123

Source: microbioscience.com

Incubation Period : The mean incubation period is 12 days but it may be as short as 6–12 h in children and non immune person. The prodrome comprises of malaise, headache, and myalgia; chill usually precedes the fever.

Mode of Transmission : Malaria is a life-threatening disease. It's typically transmitted through the bite of an infected Anopheles mosquito. Infected mosquitoes carry the Plasmodium parasite. ... Within 48 to 72 hours, the parasites inside the red blood cells multiply, causing the infected cells to burst open.

Vaccine : Malaria vaccine. Malaria vaccine is a vaccine that is used to prevent malaria. The only approved vaccine as of 2015 is RTS,S, known by the trade name Mosquirix.

Signs and Symptoms : In adults, cerebral malaria is part of a multi-organ disease. a. Patients develop fever b. Headache c. body ache d. and progressively, delirium and coma. e. Compared to African children, seizures papilledema and retinal changes are less common and coma resolution is slower.

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Diagnosis : a. Diagnosis of cerebral malaria requires demonstration of asexual form of P. falciparum in peripheral blood smear, in thick and thin blood smear films stained

by Giemsa stain. ... At least 3 smears should be negative before excluding cerebral malaria. b. The rapid diagnostic test (antigen detection test) and c. PCR Treatment : Malaria is treated with prescription drugs to kill the parasite. The types of drugs and the length of treatment will vary, depending on: a. Which type of malaria parasite you have b. The severity of your symptoms c. Your age d. Whether you're pregnant e. Medication The most common antimalarial drugs include: a. Artemisinin-based combination therapies (ACTs). ACTs are, in many cases, the first line treatment for malaria. There are several different types of ACTs. Examples include artemether-lumefantrine (Coartem) and artesunateamodiaquine. Each ACT is a combination of two or more drugs that work against the malaria parasite in different ways. b. Chloroquine phosphate. Chloroquine is the preferred treatment for any parasite that is sensitive to the drug. But in many parts of the world, the parasites that cause malaria are resistant to chloroquine, and the drug is no longer an effective treatment.

Other common antimalarial drugs include: a. b. c. d.

Combination of atovaquone and proguanil (Malarone) Quinine sulfate (Qualaquin) with doxycycline (Vibramycin, Monodox, others) Mefloquine Primaquine phosphate

5. Trypanosomiasis Or trypanosomosis is the name of several diseases in vertebrates caused by parasitic protozoan trypanosomes of the genus Trypanosoma. In humans this includes African trypanosomiasis and Chagas disease. A number of other diseases occur in other animals.

Causative Agent : African trypanosomiasis. ... It is caused by protozoa of the species Trypanosoma brucei.

Humans are infected by two types, Trypanosoma brucei gambiense (TbG) and Trypanosoma brucei rhodesiense (TbR).

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Figure 124

Source: microbewiki.com

Incubation Period : Symptoms of the acute phase disappear within 4-8 weeks in most individuals. The incubation period for Chagas disease is 7-14 d (1-2 weeks). In transfusion-acquired disease, the incubation period is longer (20-40 d). Chronic manifestations do not appear for years after infection.

Mode Of Transmission : It is caused by infection with protozoan parasites belonging to the genus Trypanosoma. They are transmitted to humans by tsetse fly (Glossina genus) bites which have acquired their infection from human beings or from animals harbouring human pathogenic parasites.

Vaccine :No effective vaccine currently exists Signs and Symptoms : a. Fever b. severe headaches c. irritability d. extreme fatigue e. swollen lymph nodes f. aching muscles and joints are common symptoms of sleeping sickness. Some people develop a skin rash. Progressive confusion, personality changes, and other neurologic problems occur after infection has invaded the central nervous system Diagnosis : The diagnosis rests on finding the parasite in body fluid or tissue by microscopy. They can also be found in lymph node fluid or in fluid or biopsy of a chancre.

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Treatment : Only four drugs are registered for the treatment of human African trypanosomiasis: pentamidine, suramin, melarsoprol and eflornithine. A fifth drug, nifurtimox, is used in combination under special authorizations.

6. Cysticercosis Is a parasitic tissue infection caused by larval cysts of the tapeworm Taenia solium.

These larval cysts infect brain, muscle, or other tissue, and are a major cause of adult onset seizures in most low-income countries.

Causative Agent : Cysticercosis is a parasitic disease caused by ingesting the eggs of the pork tapeworm, Taenia solium. Human tapeworm infection (taeniasis) occurs after ingesting raw or undercooked pork, and cysticercosis occurs after the ingestion of Taenia solium eggs.

Figure 125

Source: wikipedia.org

Incubation Period : The median incubation period for cysticercosis is estimated to be about 3.5 years and can range from 10 days to 10 years. A person who has consumed T. solium eggs may go for years without having any symptoms of infection.

Mode of Transmission : The cause of human cysticercosis is the egg form of Taenia solium (often abbreviated as T. solium and also called pork tapeworm), which is transmitted through the oral-fecal route. Eggs are accidentally ingested from contaminated water or vegetables. The eggs enter the intestine where they develop into larvae.

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Vaccine :No Vaccine Signs And Symptoms : a. Nausea and vomiting, abdominal pain. b. Headache. c. Lethargy. d. Confusion. e. Vision changes. f. Balance problems. g. Weakness or numbness. h. Seizure Diagnosis : a. The diagnosis of neurocysticercosis usually requires MRI or CT brain scans. b. Blood tests may be useful to help diagnose an infection, but they may not always be positive in light infections. If you have been diagnosed with cysticercosis, you and your family members should be tested for intestinal tapeworm infection.

Treatment : a. Treatment with albendazole and corticosteroids has proven to be beneficial. b. Some patients may require surgical excision. For intraocular cysticerci, surgical removal is preferred over antiparasitic drug therapy.

7. Hydatidosis - Is a zoonosis caused by Echinococcus granulosus, and ingesting eggs released through the faeces from infected dogs infects humans. The location of the hydatid cysts is mostly hepatic and/or pulmonary, whereas musculoskeletal hydatidosis is very rare Causative Agent : a. Infectious agent of hydatid disease (echinococcosis) b. Echinococcus granulosus (dog tapeworm) is the causative agent.

Figure 126

Source: microbewiki.com

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Figure 127

Incubation Period : Alveolar echinococcosis is characterized by an asymptomatic incubation period of 5–15 years and the slow development of a primary tumour-like lesion which is usually located in the liver.

Mode of Transmission : People become infected by ingesting (eating) eggs of the parasite, usually when there is handto-mouth transfer of eggs in dog faeces. This can occur when handling dogs or objects (including food and water) soiled with dog faeces. Person-to-person or sheep-to-person transmission does not occur.

Vaccine :No Vaccine Signs And Symptoms : a. stomach upset b. diarrhoea c. unexplained weight loss d. swollen abdomen e. anaemia f. weakness and fatigue g. cough h. blood or the fluid from a ruptured cyst – may be coughed up Diagnosis : a. granulosus is endemic suggests a diagnosis of cystic echinococcosis. Imaging techniques, such as CT scans, ultrasonography, and MRIs, are used to detect cysts. After a cyst has been detected. b. serologic tests may be used to confirm the diagnosis.

Treatment : Two benzimidazolic drugs, mebendazole and albendazole, are the only anthelmintics effective against cystic echinococcosis. Albendazole and mebendazole are well tolerated but show A Self-regulated Learning Module

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different efficacy. Albendazole is significantly more effective than mebendazole in the treatment of liver cysts.

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Unit 5: Check for facts and Understanding Microbial Infection of the Central Nervous System EVALUATE Multiple choices: Write the letter of your choice in your answer beside the number.

1.

2.

What is the causative agent of Meningitis? a.

L. monocytogenes

b.

Neisseria meningitides

c.

All of the above

d.

None of the above

Which of the following are the mode of transmission of Meningitis? a. person-to-person through droplets of respiratory or throat secretions from carriers. b. prolonged contact – such as kissing, sneezing or coughing on someone, or living in close quarters with a carrier.

3.

4.

c.

A and B

d.

B only

Which of the following are the signs and symptoms of meningitis? Except a.

headache and a stiff neck

b.

sensitivity to light

c.

confusion

d.

All of the above

What is the causative agent of Tetanus? a.

Bacteria tetany

b.

Clostridium tetani

c.

Tetanus toxoid

d.

E. Coli

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5.

6.

7.

What is the mode of transmission of tetanus? a.

A person usually becomes infected with tetanus when dirt enters a wound or cut.

b.

Respiratory droplets

c.

All of the above

d.

None of the above

What is the causative agent of Polio Myelitis? a.

serotype of the species Enterovirus C, in the family of Picornaviridae.

b.

Clostridium tetany

c.

E.Coli

d.

All of the above

Which of the following are the vaccines used in PolioMyelitis?

a. Inactivated polio vaccine (IPV) is the only polio vaccine that has been given in the United States since 2000. b. Oral polio vaccine (OPV) is used in other countries. CDC recommends that children get four doses of polio vaccine. c. b only d. a and b 8.

9.

What are the signs and symptoms of rabies? Except a.

Sore throat

b.

Poor eye sight

c.

All of the above

d.

None of the Above

What is the test that is used to detect rabies virus? a.

direct fluorescent antibody (DFA) test

b.

Blood test

c.

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d.

Skin test

10. What is the causative agent of Rabies? a.

Enterovirus C, in the family of Picornaviridae.

b.

Rabies virus (RV), a negative-stranded RNA virus of the rhabdovirus family.

c.

All of the above

d.

None of the above

11. What is the causative agent of encephalitis? a.

Rabies virus (RV), a negative-stranded RNA virus of the rhabdovirus family.

b.

herpes simplex viruses

c.

A and B

d.

None of the above

12. Which of the following are the signs and symptoms of children suffering from encephalitis?

13.

14.

a.

Bulging in the soft spots (fontanels) of an infant's skull

b.

Nausea and vomiting

c.

B only

d.

All of the above

What is the causative agent of Cerebral malaria? a.

Plasmodium species. P. falciparum

b.

Clostridium tetani

c.

a.

d.

None of the above

serotype of the species Enterovirus

What is the mode of transmission of cerebral malaria? a.

Sexual contact of the infected person

b.

Airborne

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d.

All of the above

15.What is the most severe neurological complication of infection with Plasmodium falciparum? a.

Naegleria

b.

Cerebral Malaria

c.

Acanthamoeba

d.

None of the above

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MICROBIAL INFECTION OF THE BLOOD

Figure 128

Source: myamericanurse.com

Figure 129

Source: livescience.com

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Bacterial 1. Rickettsia - are a diverse collection of obligately intracellular Gram-negative bacteria found in ticks, lice, fleas, mites, chiggers, and mammals. They include the genera Rickettsiae, Ehrlichia, Orientia, and Coxiella. These zoonotic pathogens cause infections that disseminate in the blood to many organs.

Causative Agent : The causative agent of rickettsial pox, R. akari, is transmitted by house mouse mites and circulates in mainly urban centers in Ukraine, South Africa, Korea, the Balkan states, and the United States.

Figure 130

source: cdbioscience.com

Incubation Period : The incubation period is 2–14 days. The variation in incubation period may in part be related to the inoculum size.

Mode of Transmission : Rickettsia and Orientia species are transmitted by the bite of infected ticks or mites or by the feces of infected lice or fleas. From the portal of entry in the skin, rickettsiae spread via the bloodstream to infect the endothelium and sometimes the vascular smooth muscle cells.

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Vaccine : Two types of vaccines against rickettsial infections have been developed and used in humans, whole killed bacteria and live attenuated rickettsiae. In 1924 Spencer and Parker produced a vaccine against RMSF by infecting ticks by allowing them to feed on rick-ettsemic guinea pig.

Signs And Symptoms : a. High fever b. Chills c. Severe headache d. Muscle aches e. Nausea and vomiting f. Confusion or other neurological changes g. Rash is distinctive Diagnosis : Diagnosis of rickettsial infections is often difficult. The clinical signs and symptoms (e.g., fever, headache, nausea, vomiting, and muscle aches) resemble many other diseases during the early stages when antibiotic treatment is most effective.

Laboratory tests can check a blood sample, rash specimen or the tick itself for evidence of the organism that causes the infection. Because early treatment with antibiotics is so important, doctors don't wait for these test results before starting treatment if Rocky Mountain fever is strongly suspected.

Treatment : People who develop Rocky Mountain spotted fever are much more likely to avoid complications if treated within five days of developing symptoms. That's why your doctor will probably have you begin antibiotic therapy before receiving conclusive test results.

Doxycycline (Monodox, Vibramycin, others) is the most effective treatment for Rocky Mountain spotted fever, but it's not a good choice if you're pregnant. In that case, your doctor may prescribe chloramphenicol as an alternative.

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VIRAL 1. HIV / AIDS HIV is a virus that damages the immune system. The immune system helps the body fight off infections. Untreated HIV infects and kills CD4 cells, which are a type of immune cell called T cells. Over time, as HIV kills more CD4 cells, the body is more likely to get various types of infections and cancers.

HIV (human immunodeficiency virus) is a virus that attacks cells that help the body fight infection, making a person more vulnerable to other infections and diseases.

Causative agent Human immunodeficiency virus (HIV) is the causative agent for AIDS. The most common type is known as HIV-1 and is the infectious agent that has led to the worldwide AIDS epidemic.

Figure 131

Incubation Period : The AIDS incubation period is the duration of time from initial infection with HIV to development of symptoms of the disease. Timing of diagnosis varies depending on the criteria used and their interpretation in different studies. Seroconversion times lie between 40-60 days, with wide variability.

Mode Of Transmission : HIV is spread only in certain body fluids from a person who has HIV. These fluids are blood, semen, pre-seminal fluids, rectal fluids, vaginal fluids, and breast milk. In the United States, HIV is spread mainly by having sex or sharing injection drug equipment, such as needles, with someone who has HIV. A Self-regulated Learning Module

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Vaccine : No Vaccine Signs And Symptoms : Acute HIV Infection Within 2 to 4 weeks after infection with HIV, about two-thirds of people will have a flu-like illness.

This is the body’s natural response to HIV infection.

Flu-like symptoms can include: a. Fever b. Chills c. Rash d. Night sweats e. Muscle aches f. Sore throat g. Fatigue h. Swollen lymph nodes i. Mouth ulcers These symptoms can last anywhere from a few days to several weeks. But some people do not have any symptoms at all during this early stage of HIV.

Diagnosis : Tests for HIV and AIDS. The primary tests for diagnosing HIV and AIDs include: ELISA Test ELISA, which stands for enzyme-linked immunosorbent assay, is used to detect HIV infection. If an ELISA test is positive, the Western blot test is usually administered to confirm the diagnosis.

Treatment : The main treatment for HIV is antiretroviral therapy, a combination of daily medications that stop the virus from reproducing. This helps protect CD4 cells, keeping the immune system strong enough to fight off disease. Antiretroviral therapy helps keep HIV from progressing to AIDS.

2. Hepatitis B Hepatitis B is an infection of your liver. It can cause scarring of the organ, liver failure, and cancer. It can be fatal if it isn’t treated.It’s spread when people come in contact with the blood, open sores, or body fluids of someone who has the hepatitis B virus.

Causative agent : Hepatitis B virus (HBV), a double-stranded DNA virus

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Figure 132

Source: newsmedical.net

Mode of transmission : a. Sex. You can get it if you have unprotected sex with someone who has it and your partner’s blood, saliva, semen, or vaginal secretions enter your body. b. Sharing needles. The virus spreads easily via needles and syringes contaminated with infected blood. c. Accidental needle sticks. Health care workers and anyone else who comes in contact with human blood can get it this way. d. Mother to child. Pregnant women with hepatitis B can pass it to their babies during childbirth. But there’s a vaccine to prevent newborns from becoming infected.

Incubation period : 75 days on average Vaccine : Hepatitis B vaccine Signs and symptoms : When you’re first infected, the warning signs include: a. Jaundice. (Your skin or the whites of the eyes turn yellow, and your pee turns brown or orange.) b. Light-colored poop c. Fever d. Fatigue that persists for weeks or months e. Stomach trouble like loss of appetite, nausea, and vomiting f. Belly pain

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Laboratory test : a. Hepatitis B surface antigen and antibody (HBsAg). Antigens are proteins on the hepatitis B virus. Antibodies are proteins made by your immune cells. They show up in your blood between 1 and 10 weeks after exposure. If you recover, they go away after 4 to 6 months. If they’re still there after 6 months, your condition is chronic. b. If your disease becomes chronic, your doctor might take a tissue sample from your liver, called a biopsy.

Treatment : a. Entecavir ( Baraclude ). This is the newest drug for hepatitis B. You can take it as a liquid or tablet. b. Tenofovir (Viread). This drug comes as a powder or tablet. If you take it, your doctor will check often to make sure it doesn’t hurt your kidneys. c. Lamivudine (3tc, , Epivir A/F, Epivir HBV, Heptovir). It comes as a liquid or tablet you take once a day. Most people don’t have a problem with it. But if you take it for a long time, the virus might stop responding to the drug. d. Adefovir dipivoxil ( Hepsera ). This drug, which you take as a tablet, works well for people who don’t respond to lamivudine. High doses can cause kidney problems. e. Interferon alfa ( Intron A, Roferon A, Sylatron). This medicine boosts your immune system. You take it as a shot for at least 6 months. It doesn’t cure the disease. It treats liver inflammation. Long-acting interferon, peginterferon alfa2a (Pegasys, Pegasys Proclick) can also help. This drug can make you feel bad all over or depressed, and it can and zap your appetite. It also lowers your white blood cell count, which makes it harder to fight off infection

4. Hepatitis C - is a viral infection that causes liver inflammation, sometimes leading to serious liver damage.

Causative agent : hepatitis C virus (HCV) Figure 133

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Incubation period : 2 weeks to 6 months Mode of Transmission : Hepatitis C is usually spread when blood from a person infected with the hepatitis C virus enters the body of someone who is not infected. ... People can become infected with the hepatitis C virus during such activities as: Sharing needles, syringes, or other equipment to prepare or inject drugs.

Vaccine : a. Therapeutic vaccine trial. The study population in this trial consists of people who already have chronic hepatitis C. The purpose of the trial is to determine whether each vaccine is safe and successful at reducing evidence of hepatitis C in participants' blood. Completion of this trial is expected in 2020. b. Prophylactic (preventive) vaccine trial. This trial involves people at high risk of becoming infected with hepatitis C. Its purpose is to determine the safety of the two vaccines and find out whether participants receiving either vaccine are less likely to become infected with the hepatitis C virus over a six-month period than are participants receiving a placebo (inactive) vaccine. This trial has already enrolled a large sample of participants.

Symptoms : Long-term infection with the hepatitis C virus (HCV) is known as chronic hepatitis C. Chronic hepatitis C is usually a "silent" infection for many years, until the virus damages the liver enough to cause the signs and symptoms of liver disease. a. Bleeding easily b. Bruising easily c. Fatigue d. Poor appetite e. Yellow discoloration of the skin and eyes (jaundice) f. Dark-colored urine g. Itchy skin h. Fluid buildup in your abdomen (ascites) i. Swelling in your legs j. Weight loss k. Confusion, drowsiness and slurred speech (hepatic encephalopathy) l. Spider-like blood vessels on your skin (spider angiomas)

Diagnosis : Screening for hepatitis C a. Health officials recommend that anyone at high risk of exposure to HCV get a blood test to screen for hepatitis C infection.

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b. Tests for liver damage Doctors typically use one or more of the following tests to assess liver damage in chronic hepatitis C. a. Magnetic resonance elastography (MRE). A noninvasive alternative to a liver biopsy (see below), MRE combines magnetic resonance imaging technology with patterns formed by sound waves bouncing off the liver to create a visual map showing gradients of stiffness throughout the liver. Stiff liver tissue indicates the presence of fibrosis, or scarring of the liver, as a result of chronic hepatitis C. b. Transient elastography. Another noninvasive test, transient elastography is a type of ultrasound that transmits vibrations into the liver and measures the speed of their dispersal through liver tissue to estimate its stiffness. c. Liver biopsy. Typically done using ultrasound guidance, this test involves inserting a thin needle through the abdominal wall to remove a small sample of liver tissue for laboratory testing.

Treatment : a. Antiviral medications Hepatitis C infection is treated with antiviral medications intended to clear the virus from your body. The goal of treatment is to have no hepatitis C virus detected in your body at least 12 weeks after you complete treatment.

5. Hepatitis D is a viral infection that causes liver inflammation and damage. Inflammation is swelling that occurs when tissues of the body become injured or infected. Inflammation can damage organs.

Causative agent : Hepatitis D virus (HDV) Figure 134

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Source: news-medical.net

Vaccine : There is no vaccine for hepatitis D Incubation period : HDV super infection: 2-8 weeks; HBV and HDV co-infection: 45- 160 days

Signs and Symptoms : a. Yellow skin and eyes (jaundice) b. Stomach upset c. Pain in your belly d. Throwing up e. Fatigue f. Not feeling hungry g. Joint pain h. Dark urine i. Light-colored stool

Diagnosis a. Blood test to diagnose hepatitis D. b. elastography, a special ultrasound that measures the stiffness of your liver. c. a liver biopsy, in which a doctor uses a needle to take a small piece of tissue from your liver. A pathologist will examine the tissue under a microscope to look for signs of damage or disease. d. Doctors typically use liver biopsy only if other tests don’t provide enough information about the liver damage or disease.

Treatment : If you have HDV, you may need to see a doctor who works with diseases of the digestive tract, including the liver, such as a gastroenterologist. Doctors called hepatologists specialize even further and treat only liver disease.

There’s no cure yet for HDV. Until doctors come up with better options, the drug prescribed most often is pegylated interferon alfa (peg-IFNa).

Peg-IFNa doesn’t work well for everyone. It can also cause many side effects, like lack of energy, weight loss, flu-like symptoms, and mental health issues like depression.

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6. Hepatitis G : Hepatitis G virus is spread by infected blood or blood products. It can be transmitted by sharing personal items contaminated with the virus, and other similar behaviours including from mother-to-newborn child at birth or by various sexual activities.

Causative agent : The findings suggested that the cause of this hepatitis was a yet unidentified viral agent that was named GBV. ... Serum taken in the acute stage of hepatitis from infected marmosets was found to contain two viral genomes: GBV-A and GBV-B belonging to closely-related viruses of the Flaviviridae family.

Incubation Period : The incubation period of the virus after transfusion seems to be 14-20 days, and if hepatitis occurs, the illness is typically mild.

Mode of Transmission : Hepatitis G virus is spread by infected blood or blood products. It can be transmitted by sharing personal items contaminated with the virus, and other similar behaviours including from motherto-newborn child at birth or by various sexual activities.

Vaccine :No Vaccine Signs and Symptoms : Most infected persons are asymptomatic.

Diagnosis : Blood Test Treatment:There is currently no recommended 7. Viral Hemorrhagic Fever (VHFs) are a diverse group of animal and human illnesses in which fever and hemorrhage are caused by a viral infection.

Causative Agent : VHFs may be caused by five distinct families of RNA viruses: the families Arenaviridae, Filoviridae, Bunyaviridae, Flaviviridae, and Rhabdoviridae.

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Figure 135

Source: cdbioscience.com

Incubation Period : CCHF virus – range is 1–12 days (usually 1–3 days).

Mode of Transmission : Viruses causing hemorrhagic fever are initially transmitted to humans when the activities of infected reservoir hosts or vectors and humans overlap. The viruses carried in rodent reservoirs are transmitted when humans have contact with urine, fecal matter, saliva, or other body excretions from infected rodents.

Vaccine : No vaccine Signs And Symptoms : a. fatigue, b. fever c. weakness d. dizziness e. muscle aches f. patients with more severe infections show bleeding under the skin, internal organs, or even from bodily orifices like the mouth, eyes, or ears.

Diagnosis : Doctors diagnose VHFs with blood and urine tests. These tests allow a doctor to examine a sample of blood or urine to see if it contains proteins and antibodies associated with VHFs. A Self-regulated Learning Module

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Treatment : Medications. While no specific treatment exists for most viral hemorrhagic fevers, the antiviral drug ribavirin (Rebetol, Virazole, others) may help shorten the course of some infections and prevent complications in some cases.

PARASITIC

1. Malaria is a serious and sometimes fatal disease caused by a parasite that commonly infects a certain type of mosquito which feeds on humans. People who get malaria are typically very sick with high fevers, shaking chills, and flu-like illness.

Causative agent : Malaria is caused by single-celled protozoan parasites of the genus Plasmodium. Four species infect humans by entering the bloodstream: Plasmodium falciparum, which is the main cause of severe clinical malaria and death; Plasmodium vivax; Plasmodium ovale; and Plasmodium malariae.

Figure 136

Source: microbewiki.com

Incubation Period : The incubation period between infection with malaria by a mosquito bite and initial symptoms may range from one week to one year. Generally, the incubation period ranges from nine to 14 days for P. falciparum, 12-18 days for P. vivax, and 18-40 days for P.

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Mode of Transmission : Malaria is transmitted by the bite of an infective female Anopheles mosquito. Transfusion of blood from infected persons and use of contaminated needles and syringes are other potential modes of transmission. Congenital transmission of malaria may also occur.

Vaccine : Malaria vaccine. Malaria vaccine is a vaccine that is used to prevent malaria. The only approved vaccine as of 2015 is RTS,S, known by the trade name Mosquirix. It requires four injections, and has a relatively low efficacy.

Signs And Symptoms : a. shaking chills that can range from moderate to severe b. high fever c. profuse sweating d. headache e. nausea f. vomiting g. abdominal pain h. diarrhea Diagnosis : To diagnose malaria, your doctor will likely review your medical history, conduct a physical exam and order blood tests. Blood tests are the only way to confirm a malaria diagnosis. Certain blood tests can help your doctor by showing:

a. b. c. d.

The presence of the parasite in the blood, to confirm that you have malaria Which type of malaria parasite is causing your symptoms If your infection is caused by a parasite resistant to certain drugs Other blood tests help determine whether the disease is causing any serious complications.

Treatment Malaria is treated with prescription drugs to kill the parasite. The types of drugs and the length of treatment will vary, depending on: a. Which type of malaria parasite you have b. The severity of your symptoms c. Your age d. Whether you're pregnant e. Medication A Self-regulated Learning Module

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The most common antimalarial drugs include: a. Artemisinin-based combination therapies (ACTs). ACTs are, in many cases, the first line treatment for malaria. There are several different types of ACTs. Examples include artemether-lumefantrine (Coartem) and artesunateamodiaquine. Each ACT is a combination of two or more drugs that work against the malaria parasite in different ways. b. Chloroquine phosphate. Chloroquine is the preferred treatment for any parasite that is sensitive to the drug. But in many parts of the world, the parasites that cause malaria are resistant to chloroquine, and the drug is no longer an effective treatment.

Other common antimalarial drugs include: a. b. c. d.

Combination of atovaquone and proguanil (Malarone) Quinine sulfate (Qualaquin) with doxycycline (Vibramycin, Monodox, others) Mefloquine Primaquine phosphate

2. Toxoplasmosis - Is a disease that results from infection with the Toxoplasma gondii parasite, one of the world's most common parasites. Infection usually occurs by eating undercooked contaminated meat, exposure from infected cat feces, or mother-to-child transmission during pregnancy.

Causative Agent : The pathogenic protozoan Toxoplasma gondii. T. gondii is a parasite of warm blooded animals which is present throughout the world. It is the causative agent of the diseases known as Toxoplasmosis.

Figure 137

Source: news-medical.net

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Incubation Period : In adults, the incubation period for T. gondii infection ranges from 10 to 23 days after the ingestion of undercooked meat and from five to 20 days after the ingestion of oocysts from cat feces. FIGURE 1. Pathways for Toxoplasma gondii infection.

Mode of Transmission : Animal-to-human (zoonotic) transmission. They become infected by eating infected rodents, birds, or other small animals. The parasite is then passed in the cat's feces in an oocyst form, which is microscopic. ... A Toxoplasma-infected cat that is shedding the parasite in its feces contaminates the litter box.

Vaccine : The most advanced application of the Vaxinano's technology is the first vaccine against toxoplasmosis, supported by valuable results on mice, sheep and primates. Infecting 2.5 billion of the world's population, Vaxinano is ready to reach the human vaccination market.

Signs and symptoms : a. fatigue b. headache c. body aches d. fever e. swollen lymph nodes (glands in your neck

Diagnosis : The diagnosis of toxoplasmosis is typically made by serologic testing. A test that measures immunoglobulin G (IgG) is used to determine if a person has been infected. ... Diagnosis can also be made by direct observation of the parasite in stained tissue sections, cerebrospinal fluid (CSF), or other biopsy material.

Treatment : Most healthy people don't require toxoplasmosis treatment. But if you're otherwise healthy and have signs and symptoms of acute toxoplasmosis, your doctor may prescribe the following drugs:

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a. Pyrimethamine (Daraprim). This medication, typically used for malaria, is a folic acid antagonist. It may prevent your body from absorbing the B vitamin folate (folic acid, vitamin B-9), especially when you take high doses over a long period.

For that reason, your doctor may recommend taking additional folic acid. ●

Other potential side effects of pyrimethamine include bone marrow suppression and liver toxicity. b. Sulfadiazine. This antibiotic is used with pyrimethamine to treat toxoplasmosis.

3. Leishmaniasis is a disease caused by an intracellular protozoan parasite (genus Leishmania) transmitted by the bite of a female phlebotomine sandfly. The clinical spectrum of leishmaniasis ranges from a self-resolving cutaneous ulcer to a mutilating mucocutaneous disease and even to a lethal systemic illness.

Causative Agent : Leishmaniasis is a vector borne disease that is transmitted by sand flies and caused by obligate intracellular protozoa of the genus Leishmania.

Figure 138

source: en.wikipedia.org

Figure 139

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Source: cdbioscience.com

Incubation period : lasts from 2 weeks to several months and cases up to 3 years have been reported in Old World cutaneous leishmaniasis. In New World cutaneous leishmaniasis, the incubation period is usually 2–8 weeks.

Mode of Transmission : Leishmaniasis is transmitted through the bite of female phlebotomine sandflies which bite humans and some animals, and take blood meals to feed the development of their eggs. When sandflies take blood meals from an infected person, they also become infected with the protozoa that cause leishmaniasis.

Vaccine : No Vaccine Signs And Symptoms : a. weight loss b. weakness c. fever that lasts for weeks or months d. enlarged spleen e. enlarged liver f. decreased production of blood cells g. bleeding Diagnosis : a. diagnosis of leishmaniasis has been confirmed by isolating, visualizing, and culturing the parasite from infected tissue. b. For visceral disease, the parasite can be detected through direct evidence (amastigotes in tissue) from peripheral blood, bone marrow, liver, or splenic aspirates.

Treatment : The only Food and Drug Administration (FDA)-approved medications for the treatment of leishmaniasis are intravenous liposomal amphotericin B (L-AmB) for VL and oral miltefosine for CL, ML, and VL caused by particular species.

4. Filariasis : - is a parasitic disease caused by an infection with roundworms of the Filarioidea type.

These are spread by blood-feeding insects such as black flies and mosquitoes. They belong to the group of diseases called helminthiases. Eight known filarial worms have humans as a definitive hosts.

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Causative Agent : The causative agents of lymphatic filariasis (LF) include the mosquito-borne filarial nematodes Wuchereria bancrofti, Brugia malayi, B. timori An estimated 90% of LF cases are caused by W. bancrofti (Bancroftian filariasis).

Figure 140

Source: en.wikipedia.org

Incubation Period : The incubation period is known as the period between the entrance of the infective larva into the human host and the presentation of clinical symptoms or observable signs. This period of time is completely variable, and can be as short as 4 weeks or as long as 8-16 months (Reference 18).

Mode of Transmission : The disease spreads from person to person by mosquito bites. When a mosquito bites a person who has lymphatic filariasis, microscopic worms circulating in the person's blood enter and infect the mosquito. ... The adult worms mate and release millions of microscopic worms, called microfilariae, into the blood.

Vaccines :No Vaccine Signs and symptoms : a. Fever. b. Inguinal or axillary lymphadenopathy. c. Testicular and/or inguinal pain. d. Skin exfoliation.

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e. Limb or genital swelling - Repeated episodes of inflammation and lymphedema lead to lymphatic damage, chronic swelling, and elephantiasis of the legs, arms, scrotum, vulva, and breasts.

Treatment : Diethylcarbamazine citrate (DEC), which is both microfilaricidal and active against the adult worm, is the drug of choice for lymphatic filariasis.

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Unit 5: Check for facts and Understanding Microbial Infection of the Blood EVALUATE Multiple choices: Write the letter of your choice in your answer beside the number.

1.

2.

Which of the following is the vaccine used for Rickettsia ? a.

Tetanus toxoid

b.

Whole killed bacteria and live attenuated rickettsiae

c.

Whole Killed Bacteria

d.

A and C

Which of the following are the mode of transmission of Rickettsiae? a.

transmitted by the bite of infected ticks or mites

b.

feces of infected lice or fleas. From the portal of entry in the skin

c.

A and B

d.

None of the above

3.

What is this virus that attacks the cells that help the body fight infection, making a person more vulnerable to other infections and diseases? a.

Herpes Virus

b.

Covid 19 Virus

c.

HIV virus

d.

Hepatitis Virus

4.

What do you call the infection of your liver. It can cause scarring of the organ, liver failure, and cancer. It can be fatal if it isn’t treated ? a.

Liver Cirrhosis

b.

Liver Cancer

c.

Hepatis B

d.

Liver infalmation

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5.

6.

7.

8.

What is the causative agent of HIV? a.

Herpes Virus

b.

Human immunodeficiency virus

c.

Avain Virus

d.

Covid 19 Virus

What is the confirmatory diagnostic test for HIV? a.

ELISA Test

b.

Fasting Blood Sugar Test

c.

Western Blot Test

d.

None of the above

Which of the following is the vaccine used for HIV? a.

Flu Vaccine

b.

No Vaccine developed

c.

Hepatitis Vaccine

d.

None of the above

Which of the following are the diagnostic test for Hepatitis B? a.

Western Blot Test

b.

Hepatitis B surface antigen and antibody (HBsAg)

c.

A and B

d.

None of the above

9. What do you call that disease caused by a parasite that commonly infects a certain type of mosquito which feeds on humans? a.

Japanese encephalitis

b.

Malaria

c.

Filariasis

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d.

Leprosy

10. What is the mode of transmission of malaria? a.

Bite of an infective female Anopheles mosquito.

b.

Bite of an infective male Anopheles mosquito.

c.

Bite of a tick and mites

d.

All of the above

11. What is the causative agent of Lymphatic Filariasis? a.

Wuchereria bancrofti

b.

Brugia malayi

c.

B. timori

d.

All of the above

12. What is the vaccine used for Filariasis a.

Filariasis Vaccine

b.

Wuchereria bancrofti vaccine

c.

No vaccine

d.

Brugria malayi vaccine

13. What is the causative agent of Toxoplasmosis? a.

pathogenic protozoan Toxoplasma gondii

b.

Wuchereria bancrofti

c.

All of the above

d.

None of the above

14. What is the mode of transmission of Taxoplasmosis? a.

Sexual contact

b.

Airborne, Sneezing and coughing

c.

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d.

Animal-to-human (zoonotic) transmission

15. Which of the following are the common signs and symptoms of Taxoplasmosis? a.

fatigue

b.

swollen lymph nodes (glands in your neck )

c.

A and B

d.

None of the above

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Infection of the Skin and Eyes

Figure 141

Figure 142

Source: thinkaboutyoureye.com

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Bacterial

1. Leprosy is an infectious disease that causes severe, disfiguring skin sores and nerve damage in the arms, legs, and skin areas around the body. The disease has been around since ancient times, often surrounded by terrifying, negative stigmas and tales of leprosy patients being shunned as outcasts.

Causative agent : Leprosy is caused by a slow-growing type of bacteria called Mycobacterium leprae (M. leprae).

Leprosy is also known as Hansen's disease, after the scientist who discovered M. leprae in 1873.

Figure 143

source: Cdbioscience.com

Figure 144

Source: medlife.com

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Incubation period : The bacteria are slow-growing; the incubation period for leprosy is about five years (two to 10 years), and it can take as long as about 20 years before symptoms and signs of leprosy (skin lesions, nerve damage, for example) develop in some patients.

Mode of transmission : An infection with Mycobacterium leprae or M. lepromatosis bacteria causes leprosy. ... The infection spreads from person to person by nasal secretions or droplets. Leprosy rarely spreads from chimpanzees, mangabey monkeys, and nine-banded armadillos to humans by droplets or direct contact.

Vaccine : At the moment there isn't a specific vaccine for leprosy. There is a vaccine against tuberculosis, called the BCG (Bacillus Calmette-Guérin) vaccine. This vaccine can offer some protection against leprosy. This is because the organism that causes leprosy is like the one that causes tuberculosis.

Signs and symptoms : a. the appearance of skin lesions that are lighter than normal skin and remain for weeks or months b. patches of skin with decreased sensation, such as touch, pain, and heat c. muscle weakness d. numbness in the hands, feet, legs, and arms, known as “glove and stocking anesthesia” e. eye problems f. enlarged nerves, especially in the elbows or knees g. stuffy nose and nosebleeds h. curling of the fingers and thumb, caused by paralysis of small muscles in the hand i. ulcers on the soles of the feet

Diagnosis : a. Skin smears or biopsy material that show acid-fast bacilli with the Ziel-Neelsen stain or the Fite stain can diagnose multibacillary leprosy. If bacteria are absent, paucibacillary leprosy can be diagnosed. b. Other less commonly used tests include blood exams, nasal smears, and nerve biopsies.

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In general, two antibiotics (dapsone and rifampicin) treat paucibacillary leprosy, while multibacillary leprosy is treated with the same two plus a third antibiotic, clofazimine. Usually, medical professionals administer the antibiotics for at least six to 12 months or more to cure the disease.

2. Acne It is a skin condition that occurs when your hair follicles become plugged with oil and dead skin cells. It often causes whiteheads, blackheads or pimples, and usually appears on the face, forehead, chest, upper back and shoulders. Acne is most common among teenagers, though it affects people of all ages.

Causative agent : Propionibacterium acnes (P. acnes) is the name of the bacteria that live on the skin and contributes to the infection of pimples. Research suggests that the severity and frequency of acne depend on the strain of bacteria. Not all acne bacteria trigger pimples.

Figure 145

Source:shutterstock.com

Figure 146

Source: slideshare.com

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Incubation period : Some studies recommend incubation periods of up to 21–28 days [55–57]. However, the clinical relevance and the risk of reinfection in those with late culture growth remain unknown.

Mode of transmission : No, Acne Is Not Contagious There are some skin problems that are contagious, but acne isn't one of them. Common acne (what's called acne vulgaris in med-speak) can't be passed from person to person like a cold or flu can. You can touch, hug, and kiss someone with acne without fear of catching the skin disorder.

Vaccine : No Vaccine Signs and Symptoms : a. Whiteheads (closed plugged pores) b. Blackheads (open plugged pores) c. Small red, tender bumps (papules) d. Pimples (pustules), which are papules with pus at their tips. e. Large, solid, painful lumps beneath the surface of the skin (nodules)

Diagnosis : Acne is diagnosed by a simple visual inspection by your doctor. There is no test for acne.

Rarely, a doctor may take a swab or scraping of a lesion or pustule for microbiological examination or culture to rule out other sources of infection Treatment : For moderate to severe acne, you may need oral antibiotics to reduce bacteria and fight inflammation. Usually the first choice for treating acne is tetracycline — such as minocycline or doxycycline — or a macrolide. Oral antibiotics should be used for the shortest time possible to prevent antibiotic resistance.

3. Anthrax Is a serious infectious disease caused by gram-positive, rod-shaped bacteria known as Bacillus anthracis. Anthrax can be found naturally in soil and commonly affects domestic and wild animals around the world.

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Causative agent : Anthrax is a serious infectious disease caused by gram-positive, rod-shaped bacteria known as Bacillus anthracis. Anthrax can be found naturally in soil and commonly affects domestic and wild animals around the world.

Figure 147

Source: cdbioscience.com

Incubation period : The incubation period is typically 1 day for cutaneous anthrax and 1–7 days for pulmonary anthrax. Evidence from mass exposures indicates that incubation periods up to 60 days are possible for pulmonary anthrax (related to the delayed activation of inhaled spores).

Mode of transmission : There's no evidence that anthrax is transmitted from person to person, but it's possible that anthrax skin lesions may be contagious through direct contact. Usually, anthrax bacteria enter the body through a wound in the skin. You can also become infected by eating contaminated meat or inhaling the spores.

Vaccine : The only licensed anthrax vaccine, Anthrax Vaccine Adsorbed (AVA) or BioThraxTM is indicated for active immunization for the prevention of disease caused by Bacillus anthracis, in persons 18 – 65 years of age at high risk of exposure.

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c. d. e. f.

Shortness of breath Nausea Coughing up blood Painful swallowing

Diagnosis : a. Skin testing. A sample of fluid from a suspicious lesion on your skin or a small tissue sample (biopsy) may be tested in a lab for signs of cutaneous anthrax. b. Blood tests. You may have a small amount of blood drawn that's checked in a lab for anthrax bacteria. c. Chest X-ray or computerized tomography (CT) scan. Your doctor may request a chest X-ray or CT scan to help diagnose inhalation anthrax. d. Stool testing. To diagnose gastrointestinal anthrax, your doctor may check a sample of your stool for anthrax bacteria. e. Spinal tap (lumbar puncture). In this test, your doctor inserts a needle into your spinal canal and withdraws a small amount of fluid. A spinal tap is usually done only to confirm a diagnosis of anthrax meningitis.

Treatment : The standard treatment for anthrax is a 60-day course of an antibiotic, such as ciprofloxacin (Cipro) or doxycycline (Monodox, Vibramycin, others). Which single antibiotic or combination of antibiotics will be most effective for you depends on how you were infected with anthrax, your age, your overall health and other factors. Treatment is most effective when started as soon as possible.

4. Gas gangrene Gangrene is the death of body tissue.

The infection causes toxins to form in the tissues, cells, and blood vessels of the body.

These bacteria will release toxins that cause tissue death and release a gas.

Causative agent : Gas gangrene (also known as clostridial myonecrosis and myonecrosis) is a bacterial infection that produces tissue gas in gangrene. This deadly form of gangrene usually is caused by Clostridium perfringens bacteria.

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Figure 148

Figure 149

Source: Cdbioscience.com

Incubation period : The incubation period is usually less than 24 hours but has been described to be anywhere from 7 hours to 6 weeks.

Mode of transmission : it can be spread through poor infection control practices, such as bacteria being passed from patient to patient via contaminated surgical instruments or gloves. As gas gangrene is not naturally transmitted from person to person, there is no need for patients to be isolated

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Vaccine : No vaccination Signs and symptoms : a. fever b. air under the skin c. pain in the area around a wound. d. swelling in the area around a wound e. pale skin that quickly turns gray, dark red, purple, or black f. blisters with foul-smelling discharge g. excessive sweating h. increased heart rate

Diagnosis : Diagnostic testing include: a. skin culture to test for the presence of Clostridium perfringens and other bacteria. b. blood tests to check for an abnormally high white blood cell count, which can indicate an infection.

Treatment : If gas gangrene is suspected, treatment must begin immediately. High doses of antibiotics, typically penicillin and clindamycin, are given, and all dead and infected tissue is removed surgically. About one of five people with gas gangrene in a limb requires amputation.

Staphylococcal skin infection 1. Folliculitis is a common skin condition in which hair follicles become inflamed. It's usually caused by a bacterial or fungal infection. At first it may look like small red bumps or whiteheaded pimples around hair follicles — the tiny pockets from which each hair grows.

Causative agent There are various infectious and non-infectious causes of folliculitis, and the most common causative agent is Staphylococcus aureus. In addition, several Gram-negative bacterial, fungal, parasitic, and viral pathogens can cause follicular papules and pustules.

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Figure 150

Source: Cdbioscience.com

Incubation period : The incubation period for "Pseudomonas folliculitis" is usually 48 hours (range 8 hours to 5 days) after exposure to contaminated water.

Mode of transmission : Although most folliculitis is not contagious, folliculitis caused by an infectious agents may be transmitted through person-to-person skin contact, shared razors, or through Jacuzzis or hot tubs. It is possible to give the infection to someone else through close skin contact.

Vaccine : No vaccine Signs and symptoms : a. Clusters of small red bumps or white-headed pimples that develop around hair follicles b. Pus-filled blisters that break open and crust over c. Itchy, burning skin d. Painful, tender skin e. A large swollen bump or mass

Diagnosis : a.

Skin assessment uses a technique for microscopic examination of the skin (dermoscopy). b. If initial treatments don't clear up your infection, your doctor may use a swab to take a sample of your infected skin or hair. This is sent to a laboratory to help determine what's causing the infection. Rarely, a skin biopsy may be done to rule out other conditions.

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Medications a. Creams or pills to control infection. For mild infections, your doctor may prescribe an antibiotic cream, lotion or gel. Oral antibiotics aren't routinely used for folliculitis. But for a severe or recurrent infection, your doctor may prescribe them. b. Creams, shampoos or pills to fight fungal infections. Antifungals are for infections caused by yeast rather than bacteria. Antibiotics aren't helpful in treating this type. c. Creams or pills to reduce inflammation. If you have mild eosinophilic folliculitis, your doctor may suggest you try a steroid cream to ease the itching. If you have HIV/AIDS, you may see improvement in your eosinophilic folliculitis symptoms after antiretroviral therapy.

2. Furuncle also known as a boil, is a painful infection that forms around a hair follicle and contains pus. A carbuncle is collection of boils that develop under the skin. When bacteria infect hair follicles, the follicles can swell and turn into boils and carbuncles. A furuncle starts as a red lump. It may be tender.

Causative agent : Staphylococcus aureus is the causative agent.

Figure 151

Source: microbewiki.com

Incubation period : Although the most common range of the incubation period for staphylococci is about four to 10 days, boils caused by these bacteria that are normally found on the skin are considered to have a variable incubation period.

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Mode of transmission : It is possible for boils to spread to another person if bacteria from the initially infected person contact the skin of another person who is susceptible to the infecting bacteria. However, a boil can spread in the skin of an infected individual to become an abscess or develop into a clump of boils (carbuncle).

Vaccine :No vaccine Signs and symptoms : a. A painful, red bump that starts out small and can enlarge to more than 2 inches (5 centimeters) b. Red, swollen skin around the bump c. An increase in the size of the bump over a few days as it fills with pus d. Development of a yellow-white tip that eventually ruptures and allows the pus to drain out

Diagnosis : A sample of the pus may be sent to the lab for testing. This may be useful if you have recurring infections or an infection that hasn't responded to standard treatment

Treatment : a. Treatment for stubborn furuncles generally includes steps to promote drainage and healing. b. Warm compresses can help speed the rupturing of a furuncle. Apply a warm, moist compress throughout the day to facilitate drainage. Continue to apply warmth to provide both healing and pain relief after a boil has ruptured.

3. Carbuncle Is a red, swollen, and painful cluster of boils that are connected to each other under the skin. A boil (or furuncle) is an infection of a hair follicle that has a small collection of pus (called an abscess) under the skin.

Causative agent : Caused by Staphylococcus aureus bacteria, which inhabit the skin surface, throat, and nasal passages. These bacteria can cause infection by entering the skin through a hair follicle, small scrape, or puncture, although sometimes there is no obvious point of entry.

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Figure 152

Source: mcrobewiki.com

Figure 153

Sources: msdmanuals.com

Incubation period : For staphylococci is about four to 10 days, boils caused by these bacteria that are normally found on the skin are considered to have a variable incubation period.

Mode of transmission : An active boil or carbuncle is contagious: the infection can spread to other parts of the person's body or to other people through skin-to-skin contact or the sharing of personal items.

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Signs and symptoms : a. The most obvious first symptom of a carbuncle is a red, irritated lump under your skin. Touching it may be painful. It can range from the size of a lentil to a medium-sized mushroom. b. itching before the lump appears. c. bodily aches. d. fatigue. e. fever and chills. f. skin crustiness or oozing.

Diagnosis : a. A pus sample may also be taken for lab analysis. b. If you keep developing carbuncles, it may be a sign of other health issues, such as diabetes. Your doctor may want to run urine or blood tests.

Treatment : a. You can generally treat small boils at home by applying warm compresses to relieve pain and promote natural drainage.

- For larger boils and carbuncles, treatment may include: a. Incision and drainage. Your doctor may drain a large boil or carbuncle by making an incision in it. Deep infections that can't be completely drained may be packed with sterile gauze to help soak up and remove additional pus. b. Antibiotics. Sometimes your doctor may prescribe antibiotics to help heal severe or recurrent infections.

4. Scalded skin syndrome a serious skin infection caused by the bacterium Staphylococcus aureus. This bacterium produces an exfoliative toxin that causes the outer layers of skin to blister and peel, as if they’ve been doused with a hot liquid.Staphylococcal scalded skin syndrome (SSSS) is an illness characterized by red blistering skin that looks like a burn or scald, hence its name staphylococcal scalded skin syndrome.

Causative agent : SSSS is caused by the release of two exotoxins (epidermolytic toxins A and B) from toxigenic strains of the bacteria Staphylococcus aureus.

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Figure 154

Source: sciencedirect.com

Figure :155

Source: microbewiki.com

Mode of transmission : Staphylococcal scalded skin syndrome is an acute epidermolysis caused by a staphylococcal toxin. Infants and children are most susceptible. ... Epidemics may occur in nurseries, presumably transmitted by the hands of personnel who are in contact with an infected infant or who are nasal carriers of Staphylococcus aureus.

Incubation period From skin infection to the appearance of SSSS usually is 1 to 10 days.

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Signs and symptoms : a. Red, painful areas around infection site. b. Blistering. c. Fever. d. Chills. e. Weakness. f. Fluid loss. g. Top layer of skin slips off with rubbing or gentle pressure (Nikolsky's sign)

Diagnosis Along with medical history and physical examination, diagnosis can be confirmed with: a. Skin biopsy (a sample of the skin looked at under a microscope) b. Culture of skin (a swab of skin, nose, eye and throat to look for signs of Staph aureus) c. Nikolsy’s sign (a blister formed from slight rubbing pressure on the skin) d. Additional blood tests

Treatment : Treatment of SSSS usually requires hospitalization, as intravenous antibiotics are generally necessary to eradicate the staphylococcal infection. A penicillinase-resistant, antistaphylococcal antibiotic such as flucloxacillin is used. Other antibiotics include nafcillin, oxacillin, cephalosporin and clindamycin

5. Scarlet Fever - is a bacterial illness that develops in some people who have strep throat. Also known as scarlatina, scarlet fever features a bright red rash that covers most of the body.

Scarlet fever is almost always accompanied by a sore throat and a high fever.

Causative Agent : Caused by a toxin released by the bacteria Streptococcus pyogenes (S. pyrogenes), the same organism that causes strep throat. A small percentage of patients with strep infections, such as strep throat or impetigo, develop scarlet fever.

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Figure 156

Source: slideplayer.com

Figure 157

Source: microbewiki.com

Incubation Period : The symptoms of scarlet fever usually develop two to five days after infection, although the incubation period (the period between exposure to the infection and symptoms appearing) can be as short as one day or as long as seven days. The rash feels like sandpaper to touch and it may be itchy

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Mode of Transmission : caused by the same type of bacteria that cause strep throat. In scarlet fever, the bacteria release a toxin that produces the rash and red tongue. The infection spreads from person to person via droplets expelled when an infected person coughs or sneezes.

Vaccine : no vaccine Signs and Symptoms : a. Fever of 101 F (38.3 C) or higher, often with chills. b. Very sore and red throat, sometimes with white or yellowish patches. c. Difficulty swallowing. d. Enlarged glands in the neck (lymph nodes) that are tender to the touch. e. Nausea or vomiting. f. Headache.

Diagnosis : a. throat swab may help determine which bacteria caused the infection. b. Sometimes a blood test is also ordered.

Treatment : The treatment for scarlet fever is antibiotics usually about 10 days of an oral penicillin medication (for example, amoxicillin) is effective early treatment. Rarely, some patients may need to be treated with a single injection of penicillin G benzathine (Bicillin L-A).

6. Necrotizing Fascilitis commonly known as flesh-eating disease, is an infection that results in the death of parts of the body's soft tissue. It is a severe disease of sudden onset that spreads rapidly.

Symptoms include red or purple skin in the affected area, severe pain, fever, and vomiting.

Causative agent : (commonly known as "flesh-eating infection") can be caused by more than one type of bacteria. These include Group A Streptococcus, Vibrio vulnificus, Klebsiella, Clostridium, Escherichia coli, Staphylococcus aureus and Aeromonas hydrophila.

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Figure 158

Source: microbewiki.com

Incubation period : The symptoms of necrotizing fasciitis usually occur within the first 24 hours of infection.

Mode of transmission : The bacteria that cause necrotizing fasciitis can be passed from person to person through close contact, such as touching the wound of the infected person. But this rarely happens unless the person who is exposed to the bacteria has an open wound, chickenpox, or an impaired immune system.

Vaccine : No vaccine Signs and symptoms : The early stage of necrotizing fasciitis is characterized by symptoms of a. redness b. swelling c. pain in the affected area. d. Blisters may be seen in the involved area of skin e. Fever, f. nausea, g. vomiting, h. and other flu-like symptoms are common Diagnosis : a. Taking a tissue sample (biopsy) A Self-regulated Learning Module

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b. blood work for signs of infection and muscle damage c. Imaging (CT scan, MRI, ultrasound) of the damaged area.

Treatment : a. Intravenous antibiotic therapy. b. Surgery to remove damaged or dead tissue in order to stop the spread of infection. c. Medications to raise blood pressure. d. Amputations of affected limbs, in some cases. e. Hyperbaric oxygen therapy may be recommended to preserve healthy tissue.

7. Erysipelas is a superficial form of cellulitis, a potentially serious bacterial infection affecting the skin.

Erysipelas affects the upper dermis and extends into the superficial cutaneous lymphatics. It is also known as St Anthony's fire due to the intense rash associated with it.

Causative agent Most cases of erysipelas are due to Streptococcus pyogenes (also known as beta-hemolytic group A streptococci), although non-group A streptococci can also be the causative agent. Betahemolytic, non-group A streptococci include Streptococcus agalactiae, also known as group B strep or GBS.

Figure 159

Source: Microbewiki.com

Incubation Period : Strains of erysipelas vary in their capacity to produce disease, ranging from very mild to very severe. The incubation period is 24 to 48 hours Mode of transmission :

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Erysipelas bacteria infect pigs orally via the gut and tonsil in most cases but can penetrate skin through abrasions. Infected animals shed the organism in faeces and urine and infection may be transmitted directly from pig to pig, particularly within a pen or along a drainage channel.

Vaccine :No vaccine Signs and symptoms : a. fever b. chills c. generally feeling unwell d. a red, swollen, and painful area of skin with a raised edge e. blisters on the affected area f. swollen glands Diagnosis : A blood test can reveal raised levels of white blood cells, which can indicate damage caused by an infection. In general, a doctor will be able to diagnose erysipelas by the appearance and symptoms of the affected area.

Treatment : Antibiotics, such as penicillin, are the most common treatment for erysipelas.

VIRAL

1. Chicken Pox Is an infection caused by the varicella-zoster virus. It causes an itchy rash with small, fluid-filled blisters. Chickenpox is highly contagious to people who haven't had the disease or been vaccinated against it.

Causative agent : The causative agent is called human herpes virus 3 (HHV-3) or varicella zoster virus (VZV) Figure 160

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Figure 161

Sources: wikipedia.org

Incubation Period : The average incubation period for varicella is 14 to 16 days after exposure to a varicella or a herpes zoster rash, with a range of 10 to 21 days. A mild prodrome of fever and malaise may occur 1 to 2 days before rash onset, particularly in adults. In children, the rash is often the first sign of disease

Mode of infection : Chickenpox is a highly contagious disease. It is transmitted from person to person by direct contact (touching the rash), droplet or air born spread (coughing and sneezing) of vesicle fluid or secretions of the respiratory tract of cases or of vesicle fluid of patients with herpes Zoster.

Vaccine : Varicella vaccine, also known as chickenpox vaccine, is a vaccine that protects against chickenpox. One dose of vaccine prevents 95% of moderate disease and 100% of severe disease. Two doses of vaccine are more effective than one.

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Signs and symptoms : a. High temperature (fever) b. aches c. headache often start a day or so before a rash appears d. Spots (rash). Spots appear in crops. They develop into small blisters and are itchy. They can be anywhere on the body. Several crops may develop over several days e. Loss of appetite or feeding problems

Diagnosis : Chickenpox is generally diagnose based on the rash. If there's any doubt about the diagnosis, chickenpox can be confirmed with laboratory tests, including blood tests or a culture of lesion samples.

Treatment : There is no specific treatment for chickenpox, but there are pharmacy remedies that can alleviate symptoms. a. These include paracetamol to relieve fever b. calamine lotion and cooling gels to ease itching. In most children, the blisters crust up and fall off naturally within one to two weeks.

2. German measles also known as rubella, is a viral infection that causes a red rash on the body. Aside from the rash, people with German measles usually have a fever and swollen lymph nodes.

Causative agent : The disease is caused by rubella virus, a togavirus that is enveloped and has a single-stranded RNA genome. The virus is transmitted by the respiratory route and replicates in the nasopharynx and lymph nodes. The virus is found in the blood 5 to 7 days after infection and spreads throughout the body.

Figure 162

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Source: Shuttershock.net

Incubation Period : The average incubation period of rubella virus is 17 days, with a range of 12 to 23 days. People infected with rubella are most contagious when the rash is erupting, but they can be contagious from 7 days before to 7 days after the rash appears.

Mode of transmission : Rubella is spread by direct contact with nasal or throat secretions of infected individuals.

Rubella can also be transmitted by breathing in droplets that are sprayed into the air when an infected person sneezes, coughs or talks.

Vaccine : Rubella can be prevented with MMR vaccine. This protects against three diseases: measles, mumps, and rubella. CDC recommends children get two doses of MMR vaccine, starting with the first dose at 12 through 15 months of age, and the second dose at 4 through 6 years of age.

Signs and symptoms : a. pink or red rash that begins on the face and then spreads downward to the rest of the body b. mild fever, usually under 102°F c. swollen and tender lymph nodes d. runny or stuffy nose. e. headache f. muscle pain g. inflamed or red eyes Diagnosis :

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a. Culture test or a blood test, which can detect the presence of different types of rubella antibodies in your blood. These antibodies indicate whether you've had a recent or past infection or a rubella vaccine.

Treatment : There is no effective antiviral treatment for rubella. Treatment of symptoms includes a. plenty of fluids and pain relief if required b. Paracetamol may be used to reduce fever and pain c. Aspirin should not be given to children under 12 years of age unless specifically recommended by a doctor 3. Measles - is an acute viral respiratory illness. It is characterized by a prodrome of fever (as high as 105°F) and malaise, cough, coryza, and conjunctivitis -the three “C”s -, a pathognomonic enanthema (Koplik spots) followed by a maculo papular rash . The rash usually appears about 14 days after a person is exposed.

Causative agent : Is a respiratory infection known as 'morbillivirus'. This highly contagious disease is spread by droplets in the air or by direct contact.

Figure 163

Source: medicalnewstoday.com

Figure 164

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Source: microbewiki.com

Incubation Period : Measles virus is shed from the nasopharynx beginning with the prodrome until 3–4 days after rash onset. The incubation period of measles, from exposure to prodrome, averages 10–12 days. From exposure to rash onset averages 14 days (range, 7–21 days). The prodrome lasts 2–4 days (range 1–7 days).

Mode of transmission : Measles is one of the most contagious of all infectious diseases; up to 9 out of 10 susceptible persons with close contact to a measles patient will develop measles. The virus is transmitted by direct contact with infectious droplets or by airborne spread when an infected person breathes, coughs, or sneezes.

Vaccine : Measles can be prevented with MMR vaccine. The vaccine protects against three diseases: measles, mumps, and rubella. CDC recommends children get two doses of MMR vaccine, starting with the first dose at 12 through 15 months of age, and the second dose at 4 through 6 years of age.

Signs and Symptoms : a. Fever b. Dry cough c. Runny nose d. Sore throat e. Inflamed eyes (conjunctivitis) f. Tiny white spots with bluish-white centers on a red background found inside the mouth on the inner lining of the cheek — also called Koplik's spots Diagnosis :

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Doctors can confirm measles by examining your skin rash and checking for symptoms that are characteristic of the disease, such as white spots in the mouth, fever, cough, and sore throat.

Treatment : Medications Fever reducers. You or your child may also take over-the-counter medications such as acetaminophen (Tylenol, others), ibuprofen (Advil, Children's Motrin, others) or naproxen (Aleve) to help relieve the fever that accompanies measles. Don't give aspirin to children or teenagers who have measles symptoms.

4. Small Pox Is an infectious disease caused by one of two virus variants, Variola major and Variola minor. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) certified the global eradication of the disease in 1980.

Causative agent : The Variola virus, which is the most virulent member of Genus Orthopoxvirus, is the causative agent of smallpox. It specifically infects humans. The primary reason for infection in humans is due to its ability to evade the host immune responses, and avoid complement activation.

Figure 165

source: news-medicak.com

Figure 166

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Source: microbeswiki.com

Incubation Period : incubation period of between 7 and 17 days after exposure and only becomes infectious once the fever develops. A distinctive rash appears two to three days later.

Mode of transmission : Variola virus is most frequently transmitted from an infectious person via direct deposition of large, infective airborne droplets of saliva onto the nasal, oral or pharyngeal mucosal membranes, during close, face-to-face contact with a susceptible individual.

The smallpox vaccine, introduced by Edward Jenner in 1796, was the first successful vaccine to be developed. He observed that milkmaids who previously had caught cowpox did not catch smallpox and showed that inoculated vaccinia protected against inoculated variola virus.

Signs and Symptoms : a. sudden onset of high fever which may be recurrent. b. malaise (general feeling of unwellness) c. widespread skin rash – flat spots which change into raised bumps then firm fluid filled blisters which then scab (see image) d. severe headache. e. backache. f. abdominal pain. g. vomiting. h. diarrhoea.

Diagnosis : The disease can be definitively diagnosed by isolation of the virus from the blood or lesions, or by identification of antibodies in the blood made in response to the virus. The diagnosis of A Self-regulated Learning Module

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smallpox is made in specialized laboratories with appropriate testing techniques and measures to protect the laboratory workers.

Treatment : a. Antiviral Drugs In July 2018, the FDA approved tecovirimat (TPOXX) for treatment of smallpox. In laboratory tests, tecovirimat has been shown to be effective against the virus that causes smallpox. In laboratory tests, cidofovir and brincidofovir have been shown to be effective against the virus that causes smallpox.

5. Warts are small, grainy skin growths that occur most often on your fingers or hands. Rough to the touch, common warts also often feature a pattern of tiny black dots, which are small, clotted blood vessels.

Causative agent : Warts are small growths on the skin caused by a virus known as human papillomavirus (HPV).

Figure 167

Source: dermatologyadviser.com

Figure 168 A Self-regulated Learning Module

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Source: en.wikipedia.org

Incubation Period : 2 to 3 months, with a range of 1 to 20 months for genital warts. It can take up to 10 years for a high-risk HPV infection to develop into cancer.

Mode of transmission : Transmission: Warts are transmitted by direct contact or indirect contact (e.g., public showers or swimming pool areas). They can be transmitted to one's self or others. Picking or scratching at warts can increase the risk of transmission.

Vaccine : The human papillomavirus (HPV) vaccine is intended to prevent people from getting infected with the virus, but in some cases, it may actually work as a treatment, clearing warts in people who are already infected, a new report suggests.

Signs and symptoms : Characteristic of the warts a. Small, fleshy, grainy bumps on the skin b. Flesh-colored, white, pink or tan. c. Rough to the touch. d. Sprinkled with black pinpoints, which are small, clotted blood vessels.

Diagnosis :

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Examining the wart a. Scraping off the top layer of the wart to check for signs of dark, pinpoint dots — clotted blood vessels — which are common with warts. b. Removing a small section of the wart (shave biopsy) and sending it to a laboratory for analysis to rule out other types of skin growths.

Treatment : a. Stronger peeling medicine (salicylic acid). Prescription-strength wart medications with salicylic acid work by removing layers of a wart a little bit at a time. b. Freezing (cryotherapy). Freezing therapy done at a doctor's office involves applying liquid nitrogen to your wart. c. Laser treatment

FUNGAL

1. Superficial mycoses Superficial (or cutaneous) mycoses are fungal diseases that are confined to the outer layers of the skin, nail, or hair, (keratinized layers), rarely invading the deeper tissue or viscera, without inducing a cellular response from the host.

Causative agent : They are caused by filamentous fungi of the genera Trichophyton, Microsporum and Epidermophyton spp. Malassezia species are commensal yeasts on normal skin, but under certain conditions can cause human disease such as pityriasis versicolor.

Figure 169

Source: slideshare.com

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Figure 170

Incubation Period : Infections are most common in post pubertal hosts, except for tinea capitis which is more common in children with an incubation period of typically 1 to 3 weeks.

Mode of transmission : The fungi invade only the dead, cornified layers of the skin, nails and hair. Most of the resulting pathology is caused by the host's reaction to the infecting fungus. ... During colonization the surface of the tissue is infected with a fungal spore and invasion begins.

Vaccine : No Vaccine Signs and symptoms : a. Premycotic phase: A scaly, red rash in areas of the body that usually are not exposed to the sun. This rash does not cause symptoms and may last for months or years. It is hard to diagnose the rash as mycosis fungoides during this phase. b. Patch phase: Thin, reddened, eczema-like rash. c. Plaque phase: Small raised bumps (papules) or hardened lesions on the skin, which may be reddened. d. Tumor phase: Tumors form on the skin. These tumors may develop ulcers and the skin may get infected.

Diagnosis : Laboratory Diagnosis of Fungal Infections

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Superficial and cutaneous mycoses may be identified by microscopic analysis, either by analysis of wet skin scrapings or by visualization after staining.

Treatment : KETOCONAZOLE. First broad-spectrum antifungal drug administered orally. Topically, it is indicated in all superficial mycoses and seborrheic dermatitis. Oral treatment should be reserved for cases of extensive, severe or recalcitrant disease or if there was a previous failure with topical treatment.

2. Cutaneous mycoses - These are superficial fungal infections of the skin, hair or nails. No living tissue is invaded, however a variety of pathological changes occur in the host because of the presence of the infectious agent and its metabolic products

Causative agent : Cutaneous Mycoses may be classified as dermatophytoses or dermatomycoses.

Dermatophytoses are caused by the agents of the genera Epidermophyton, Microsporum, and Trichophyton. Dermatomycoses are cutaneous infections due to other fungi, the most common of which are Candida spp.

Figure 171

source: dermatologyadviser.com

Figure 172

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Source: microbeswik.com

Incubation Period : verrucosum, and T. equinum occur worldwide. Infections are most common in postpubertal hosts, except for tinea capitis which is more common in children with an incubation period of typically 1 to 3 weeks.

Mode of Transmission : They are spread from infected persons by direct contact. Microsporum is also spread from animals such as dogs and cats. ... Dermatophytoses (tinea, ringworm) are chronic infections often located in the warm, humid areas of the body (e.g., athlete's foot.

Vaccine : No Vaccine Signs and symptoms : Symptoms may be absent or a. b. c.

include burning or dryness of the mouth loss of taste pain on swallowing Cutaneous candidiasis: including intertrigo, diaper candidiasis, paronychia and onychomycosis.

Diagnosis : Laboratory Diagnosis of Fungal Infections a. Superficial and cutaneous mycoses may be identified by microscopic analysis, either by analysis of wet skin scrapings or by visualization after staining.

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Treatment : The main groups of systemic antifungal agents normally used for treating superficial and cutaneous mycoses are imidazole (Ketoconazole), triazole (fluconazole and itraconazole) and alilamine (terbinafine).

PARASITIC 1. Filariasis - Filariasis is a parasitic disease caused by an infection with roundworms of the Filarioidea type. These are spread by blood-feeding insects such as black flies and mosquitoes. They belong to the group of diseases called helminthiases. Eight known filarial worms have humans as a definitive hosts.

Causative agent : Lymphatic filariasis is caused by the worms Wuchereria bancrofti, Brugia malayi, and Brugia timori. These worms occupy the lymphatic system, including the lymph nodes; in chronic cases, these worms lead to the syndrome of elephantiasis.

Figure 173

Source:en.wkipedia.org

Figure 174

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Source: who.int

Incubation Period : The incubation period for filariasis is between 9 and 12 months. Half of infected individuals in endemic areas develop the asymptomatic form of the disease, and, despite being healthy, they have microfilaria in their blood.

Mode of transmission : The disease spreads from person to person by mosquito bites. When a mosquito bites a person who has lymphatic filariasis, microscopic worms circulating in the person's blood enter and infect the mosquito. ... The adult worms mate and release millions of microscopic worms, called microfilariae, into the blood.

Vaccine: No vaccine Signs and symptoms : a. Fever. b. Inguinal or axillary lymphadenopathy c. Testicular and/or inguinal pain d. Skin exfoliation e. Limb or genital swelling - Repeated episodes of inflammation and lymphedema lead to lymphatic damage, chronic swelling, and elephantiasis of the legs, arms, scrotum, vulva, and breasts.

Diagnosis : The standard method for diagnosing active infection is the identification of microfilariae in a blood smear by microscopic examination. ... Patients with active filarial infection typically have elevated levels of antifilarial IgG4 in the blood and these can be detected using routine assays.

Treatment : The main goal of treatment of an infected person is to kill the adult worm. Diethylcarbamazine citrate (DEC), which is both microfilaricidal and active against the adult worm, is the drug of choice for lymphatic filariasis. The late phase of chronic disease is not affected by chemotherapy.

2. Dermatitis

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Is a common condition that has many causes and occurs in many forms. It usually involves itchy, dry skin or a rash on swollen, reddened skin. Or it may cause the skin to blister, ooze, crust or flake off. Examples of this condition are atopic dermatitis (eczema), dandruff and contact dermatitis.

Causative agent : Staphylococcus Aureus As A Causative Agent Of Atopic Dermatitis/ Eczema Syndrome (ADES ) And Its Therapeutic Implications.

Figure 175

Souce: myoclinic.org

Figure 176

Incubation Period : The incubation period between exposure and the onset of symptoms is minutes to hours so that the patient usually is aware of the identity of the causal substance. Allergic contact dermatitis is much more difficult to diagnose.

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Mode of Transmission : irritant dermatitis often occurs on the hands of people who frequently get them wet. Allergic contact dermatitis occurs upon exposure to an allergen, causing a hypersensitivity reaction in the skin. Antibiotics may be required if there are signs of skin infection.

Vaccine : No Vaccine Signs And Symptoms : a. A red rash. b. Itching, which may be severe. c. Dry, cracked, scaly skin. d. Bumps and blisters, sometimes with oozing and crusting. e. Swelling, burning or tenderness.

Diagnosis : No lab test is needed to identify atopic dermatitis (eczema). Your doctor will likely make a diagnosis by examining your skin and reviewing your medical history. He or she may also use patch testing or other tests to rule out other skin diseases or identify conditions that accompany your eczema.

Treatment : To reduce inflammation and heal the irritation of most types of dermatitis, usually recommends a prescription corticosteroid cream and might prescribe an oral antihistamine to relieve severe itching. You may need an antibiotic if a secondary infection develops.

3. Onchocerciasis also known as river blindness, is a disease caused by infection with the parasitic worm Onchocerca volvulus. Symptoms include severe itching, bumps under the skin, and blindness. It is the second-most common cause of blindness due to infection, after trachoma.

Causative agent : Onchocerciasis (river blindness) is a parasitic disease caused by the filarial worm Onchocerca volvulus. It is transmitted through the bite of infected black flies of the genus Simulium, which carry the immature larval form of O. volvulus (known as microfilaria).

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Figure 177

Source:sciencedirect

Figure 178

Source: pinterest.com

Incubation Period : The incubation varies from host to host and by the amount of bites from infected vectors. The generally accepted incubation period ranges from 3 months-2 years. This is considered the time from initial infection to the time that the mature filariae produce larvae.

Mode of Transmission : The disease spreads by the bite of an infectious blackfly. When a blackfly bites a person who has onchocerciasis, microscopic worm larvae (called microfilariae) in the infected person's skin are ingested by the blackfly. The larvae develop over approximately one week in the fly to a stage that is infectious to humans.

Vaccine : No Vaccine Signs and Symptoms : A Self-regulated Learning Module

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a. b. c. d. e. f. g.

Skin inflammation that is very itchy and forms papules on the skin Nodules in the skin (subcutaneous nodules or bumps) Scarred, saggy, or drooping areas of skin Patchy skin depigmentation (leopard skin) Lymph node inflammation (lymphadenitis) Eye (ocular) lesions (eye itching, redness, or swelling) Visual problems (visual impairment and/or inability to distinguish certain colors, partial or complete blindness) h. Eosinophilia (unusually high levels of eosinophils in the blood) i. "Sowda" is a term used to describe the severe itching and skin discoloration (darkening), that is often confined to one limb, that can be found with onchocerciasis.

Diagnosis : The gold standard test for the diagnosis of onchocerciasis remains the skin snip biopsy. The biopsy is performed using a sclerocorneal biopsy punch or by elevating a small cone of skin (3 mm in diameter) with a needle and shaving it off with a scalpel. This will result in the removal of around 2 mg of tissue .

Treatment : The treatment for onchocerciasis is ivermectin (Mectizan®). Ivermectin paralyses and kills microfilariae, relieving intense skin itching and halting the progression towards blindness. It also prevents adult worms from producing more microfilariae for a few months following treatment, so reduces transmissio

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Unit 5: Check for facts and Understanding Microbial Infection of the Skin and Eyes EVALUATE Multiple choices: Write the letter of your choice in your answer beside the number.

1.

What is this disease that causes severe, disfiguring skin sores and nerve damage in the arms, legs, and skin areas around the body?

2.

3.

4.

a.

Leprosy

b.

Filariasis

c.

Anthrax

d.

Measles

Which of the following is the causative agent of leprosy? a.

Salmonella Typhi

b.

Bacteria Leprosy

c.

Mycobacterium leprae

d.

None of the above

What is the mode of transmission of leprosy? a.

Skin to skin contact

b.

Person to person by nasal secretions or droplets.

c.

Zoonotic( animals to humans )

d.

Fecal route

Which of the following are the signs and symptoms of Anthrax ? except a.

Flu-like symptoms, such as sore throat, mild fever, fatigue and muscle aches, which may last a few hours or days b.

Mild chest discomfort

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5.

c.

Shortness of breath

d.

Weight Gain

What is the causative agent of anthrax? a.

Bacillus anthracis

b.

Bacillus anthrax

c.

Mycobacterium laprae

d.

None of the above

6. What is this infection that causes an itchy rash with small, fluid-filled blisters that is caused by the varicella-zoster virus.

7.

a.

Measles

b.

Small pox

c.

Chicken pox

d.

Scarlet fever

Which are the following signs and symptoms of Chicken pox ? except a.

headache often start a day or so before a rash appears

b.

Spots (rash). Spots appear in crops. They develop into small blisters and are itchy. They can be anywhere on the body. Several crops may develop over several days

8.

c.

Loss of appetite or feeding problems

d.

Loose bowel movement

What is the causative agent of measles? a.

Morbilli virus

b.

Varicella virus

c.

Flu virus

d.

None of the above

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9.

What is the mode of transmission of measles? a.

Ingestion of infected feces

b.

Animal to human contact

c.

droplets or by airborne

d.

All of the above

10. Which of the following are the signs and symptoms of small Pox? a. sudden onset of high fever which may be recurrent, malaise (general feeling of un wellness) b. widespread skin rash – flat spots which change into raised bumps then firm fluid filled blisters which then scab c.

A only

d.

All of the above

11. What is the causative agent of Small pox? a.

Morbilli virus

b.

Variola virus

c.

Varicela virus

d.

Flu Virus

12. What is the treatment for small pox? a.

Antibacterial drugs

b.

Anti helminthic drugs

c.

Antiviral Drugs

d.

None of the above

13. What is the mode of transmission of Filariasis? a.

person to person by mosquito bites

b.

Skin to skin contact

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c.

Airborne, sneezing and coughing

d.

Fecal infested foods

14. Which of the following are the signs and symptoms of filariasis? a.

Testicular and/or inguinal pain

b.

Skin exfoliation

c.

Limb or genital swelling - Repeated episodes of inflammation and lymphedema lead to lymphatic damage, chronic swelling, and elephantiasis of the legs, arms, scrotum, vulva, and breasts. d.

All of the above

15. What is the causative agent of filariasis? a.

Wuchereria bancrofti

b.

Morbilli Virus

c.

Vacirela Virus

d.

None of the above

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ACTIVITY 6 CHEMICAL STERILIZATION

I. OBJECTIVE The students are expected to discuss the different chemical means of eliminating microorganisms and to select the appropriate disinfectant to a particular situation

II. DISCUSSION Sterilization is the destruction of all micro-organisms and spores. Exposure to laboratory works provides a potential possibility of contamination. Three aspects to where contamination prevention should be observed include contamination of the specimen for diagnostic purposes, cross contamination between patients and self-contamination of the medical practitioner from their patients Aside from physical sterilization, radiation, chemical and filtration are the other methods. In chemical sterilization, chemicals are used to sterilize items that will be damaged by high temperatures, like ethylene oxide.

Several factors affect the action of physical and chemical sterilization, namely temperature, concentration of the chemical and the length of time of the microbe’s exposure to the chemical.

These factors may be expressed as follows: N = 1/CT Where: N = number of surviving microorganisms C = concentration T = time From this equation, we can conclude that as the concentration of a disinfectant is increased, the number of surviving microbe is decreased and as the time of exposure of the microbe to the disinfectant is increased, the number of surviving microbes is decreased.

III. MATERIALS Pencil, PPEs (lab gown), Reference materials IV. Questions for research

A.

SCORING RUBRIC

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5 POINTS EACH QUESTION

FOR

5

OUTSTANDING; No mistake identified

4

EXCELLENT; 2 Mistakes or missing concepts identified

3

GOOD; 3 mistakes or missing concepts identified

2

FAIR; 4 mistakes or missing concepts identified

1

POOR; 5 mistakes or missing concepts is identified

0

The answer is totally different from the expected response

1. Which antiseptic is the most recommended for surgical operations? Why?

2. Why is 70% the optimum concentration used in the preparation of ethyl alcohol as an antiseptic?

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3. Describe and explain the principle of action of the following chemicals and give at least 2 examples for each. a. alcohols

b. aldehydes

c. gaseous agents

d. halogens

e. heavy metals

f. oxidizing agents

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h. surfactants

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UNIT VI CONTROL AND TREATMENT Objectives: 1. Identify the characteristics of an ideal antimicrobial agent.

2. State the most common mechanisms of action of antimicrobial agents 3. Differentiate between bactericidal and bacteriostatic agents 4. State the difference between narrow-spectrum and broad-spectrum antimicrobial Agents.

5. State three undesirable effects of antimicrobial agents 6. Compare and contrast antimicrobial agents, and antibiotics as to their intended purpose 7. Understand the factors that impact on hand hygiene compliance 8. Be able to describe the ideal facilities required for hand hygiene 9. Understand the importance of hand hygiene in infection prevention 10. Be familiar with interventions to improve hand hygiene compliance rates.

PRECEDE: 1. What are the standard 2. What do we mean by PPE and what are these?

3. How do we separate medical garbage?

4. How to do disinfection and sterilization?

1. Control of microbial growth with disinfectants and antiseptics.

A. Standard safety measures Standard Precautions are the minimum infection prevention practices that apply to all patient care, regardless of suspected or confirmed infection status of the patient, in any setting where healthcare is delivered. These practices are designed to both protect medical practitioners and prevent patients from spreading infections among patients.

Standard precautions are a set of infection control practices used to prevent transmission of diseases that can be acquired by contact with blood, body fluids, non-intact skin (including rashes), and mucous membranes. These measures are to be used when providing care to all individuals, whether or not they appear infectious or symptomatic.

Standard Precautions include — 1.

2.

3.

4.

5.

6.

7.

Hand hygiene.

Use of personal protective equipment (e.g., gloves, masks, eyewear).

Respiratory hygiene / cough etiquette.

Sharps safety (engineering and work practice controls).

Safe injection practices (i.e., aseptic technique for parenteral medications).

Sterile instruments and devices.

Waste Disposal in Clinical Procedures.

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When Standard Precautions alone cannot prevent transmission, they are supplemented with Transmission-Based Precautions. This second tier of infection prevention is used when patients have diseases that can spread through contact, droplet or airborne routes (e.g., skin contact, sneezing, coughing) and are always used in addition to Standard Precautions.

Hand Hygiene:

Is a major component of standard precautions and one of the most effective methods to prevent transmission of pathogens associated with health care. In addition to hand hygiene, the use of personal protective equipment should be guided by risk assessment and the extent to contact anticipated with blood and body fluids or pathogens.

In addition to practices carried out by health workers when providing care, all individuals (including patients and visitors) should comply with infection control practices in health-care settings. The control of spread of pathogens from the source is key to avoid transmission.

Among source control measures, respiratory hygiene/cough etiquette, developed during the severe acute respiratory syndrome (SARS) outbreak, is now considered as part of standard precautions.

Worldwide escalation of the use of standard precautions would reduce unnecessary risks associated with health care. Promotion of a Institutional safety climate helps to improve conformity with recommended measures and thus subsequent risk reduction. Provision of adequate staff and supplies, together with leadership and education of health workers, patients and visitors is critical for an enhanced safety climate in health-care settings.

Important Advice ☞ Promotion of a safety climate is a cornerstone of prevention of transmission of pathogen in health care. ☞ Standard precautions should be the minimum level of precautions used when providing care for all patients. ☞ Risk assessment is critical. Assess all health-care activities to determine the personal protection that is indicated. ☞ Implement source control measures for all persons with respiratory symptoms through promotion of respiratory hygiene and cough etiquette.

Health Policy ✔ Promote a safety climate ✔ Develop policies which facilitate the implementation of infection control measures.

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Hand Hygiene: ✔ Perform hand hygiene by means of hand rubbing or hand washing. ✔ Hands should always be washed with soap and water if hands are visibly soiled, or exposure to spore-forming organisms is proven or strongly suspected, or after using the restroom. For other indications, if resources permit, perform hand rubbing with an alcohol-based preparation. ✔ Ensure availability of hand-washing facilities with clean running water. ✔ Ensure availability of hand hygiene products (clean water, soap, single use clean towels, alcohol-based hand rub). Alcohol-based hand rubs should ideally be available at the point of care.

Why do Hand Hygiene? ✔ Thousands of people die everyday around the world from infections acquired while receiving health care. ✔ Hands are the main pathways of germ transmission during health care. ✔ Hand Hygiene is therefore the most important measure to avoid the transmission of harmful germs and prevent health care-associated infections. ✔ This brochure explains how and when to practice hand hygiene.

WHO do Hand Hygiene? ✔ Any health-care worker, caregiver or person involved in direct or indirect patient care needs to be concerned about hand hygiene and should be able to perform it correctly and at the right time.

Five Moments of Hand Hygiene: Hand hygiene must be practiced: 1. Before touching a patient.

2. Immediately before performing a clean or aseptic procedure, including handling an invasive device for patient care, regardless of whether or not gloves are used.

3. Promptly after contact with body fluids, excretions, mucous membranes, non-intact skin, or wound dressings regardless of whether or not gloves were used.

4. After touching a patient and his/her immediate surroundings, even when leaving the patient’s side.

5. After contact with in animate objects (including medical equipment and furniture) in the immediate vicinity of the patient.

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How to perform the right hand washing; illustrate how to do the correct hand washing through pictures of the correct sequence of general hand washing.

What is your nursing care after hand washing?

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Rubrics: CATEGORY GRAPHICA-CLARITY

GRAPHICS RELEVANCE

LABELS

SEQUENCE

16 Graphics are focus and related to the topic All graphics are related to the topic and make it easier to understand. All borrowed graphics have a source citation.

All items of importance on the poster are clearly labeled with labels that can be read All pictures are in the right sequence and well numbered

8 Some graphics are not easily viewed and unclear All graphics are related to the topic and most make it easier to understand.

Several items of importance on the pictures are clearly labeled with labels that can be read.

Some of the pictures are not in sequence

4 All graphics are not clear Graphics do not relate to the topic

Labels are too small to view OR no important items were labeled.

Pictures are not in the right sequence.

Personal Protective Equipment: ⮚ Personal protective equipment (PPE) refers to wearable equipment that is designed to protect health workers from exposure to or contact with infectious agents. PPE that is appropriate for various types of patient interactions and effectively covers personal clothing and skin likely to be soiled with blood, saliva, or other potentially infectious materials (OPIM) should be available. These include gloves, face masks, protective eye wear, face shields, and protective clothing (e.g., reusable or disposable gown, jacket, laboratory coat). ⮚ ASSESS the RISK of exposure to body substances or contaminated surfaces BEFORE any health-care activity. Make this a routine! ☞ Clean non-sterile gloves ☞ Clean, non-sterile fluid-resistant gown ☞ Mask and eye protection or a face shield. ⮚ Examples of appropriate use of PPE for adherence to Standard Precautions include— ☞

Use of gloves in situations involving possible contact with blood or body fluids, mucous membranes, non-intact skin (e.g., exposed skin that is chapped, abraded, or with dermatitis) or OPIM.

☞

Use of protective clothing to protect skin and clothing during procedures or activities where contact with blood or body fluids is anticipated.

☞

Use of mouth, nose, and eye protection during procedures that are likely to generate splashes or sprays of blood or other body fluids.

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Medical practitioners should be trained to select and put on appropriate PPE and remove PPE so that the chance for skin or clothing contamination is reduced. Hand hygiene is always the final step after removing and disposing of PPE. Training should also stress preventing further spread of contamination while wearing PPE by: ☞ ☞ ☞ ☞

Keeping hands away from face.

Limiting surfaces touched.

Removing PPE when leaving work areas.

Performing hand hygiene.

Key Recommendations for PERSONAL PROTECTIVE EQUIPMENT (PPE) in Dental Settings: 1. Provide sufficient and appropriate PPE and ensure it is accessible to all medical practitioners.

2. Educate all medical practitioners on proper selection and use of PPE. 3. Wear gloves whenever there is potential for contact with blood, body fluids, mucous membranes, non-intact skin or contaminated equipment. a.) Do not wear the same pair of gloves for the care of more than one patient. b.) Do not wash gloves. Gloves cannot be reused. c.) Perform hand hygiene immediately after removing gloves.

4. Wear protective clothing that covers skin and personal clothing during procedures or activities where contact with blood, saliva, or OPIM is anticipated.

5. Wear mouth, nose, and eye protection (Face shield) during procedures that are likely to generate splashes or spattering of blood or other body fluids.

6. Remove PPE before leaving the work area.

CATEGORY GRAPHIC-CLARITY

GRAPHICS RELEVANCE

LABELS

15 Graphics are focus and related to the topic All graphics are related to the topic and make it easier to understand. All borrowed graphics have a source citation.

All items of importance on the poster are clearly labeled with labels that can be read.

Functions are correct

10 Some graphics are not easily viewed and unclear All graphics are related to the topic and most make it easier to understand.

Several items of importance on the pictures are clearly labeled with labels that can be read.

Unclear/some are incorrect

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Labels are too small to view OR no important items were labeled.

Incorrect labels

354

Paste down the proper medical PPE and label with their proper functions:

☞ Persons with respiratory symptoms should apply source control measures such as covering their nose and mouth when coughing/sneezing with tissue or mask, dispose of used tissues and masks and perform hand hygiene after contact with respiratory secretions.

Respiratory Hygiene/Cough Etiquette ☞ infection prevention measures are designed to limit the transmission of respiratory pathogens spread by droplet or airborne routes. The strategies target primarily patients and individuals accompanying patients to the dental setting who might have undiagnosed transmissible respiratory infections, but also apply to anyone (including health workers) with signs of illness including cough, congestion, runny nose, or increased production of respiratory secretions. ☞ Health Care Practitioner should be educated on preventing the spread of respiratory pathogens when in contact with symptomatic persons. Respiratory hygiene/cough etiquette measures were added to Standard Precautions in 2007.

Health Care Facilities should: ☞ Place acute febrile respiratory symptomatic patients at least 1 metre (3 feet) away from others in common waiting areas, if possible. ☞ Post visual alerts at the entrance to health-care facilities instructing persons with respiratory symptoms to practice respiratory hygiene/cough etiquette ☞ Consider making hand hygiene resources, tissues and masks available in common areas and areas used for the evaluation of patients with respiratory illnesses.

What measures are included in respiratory hygiene and cough etiquette? ~ Respiratory hygiene and cough etiquette include a number of measures developed to prevent the spread of respiratory infections in healthcare facilities, especially in facilities where patients, employees, and visitors may not be immediately recognized as having a respiratory infection.

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For healthcare facilities, some of these measures may need to be adapted to the type of facility, and the types of persons (employees, patients, and visitors) in the facility. The elements of respiratory hygiene/cough etiquette include: ≈ Education of patients, families, visitors, and care providers about how respiratory infections are transmitted and respiratory illness can be prevented. This includes asking family members, visitors, and care providers to stay home if they are sick. ≈ ≈

Use of posted signs (in languages appropriate to the population served) with instructions and pictures about how to cover your cough and wash your hands.

Availability and use of disposal tissues when coughing and sneezing, and reminders to dispose of used tissues properly.

≈

Use of a mask for a person who is coughing. A mask should only be used if the patient can tolerate the mask and until the person can be placed in a location where risks to others are minimized.

≈

Spatial separation of the person with a respiratory infection from others. Since droplets travel through the air for 3-6 feet, separating an ill person from others by more than 3 feet decreases risk of transmission. If a patient is ill and shares a room, the use of curtains or screens between beds can limit dispersal of droplets.

≈

Stressing hand hygiene after contact with respiratory secretions. This applies to the patient, family members, visitors, employees, and care providers.

Sharps Safety ⮚ Most percutaneous injuries (e.g., needlestick, cut with a sharp object) among Health Care Practitioners involve needles, and other sharp instruments. Implementation of the OSHA Bloodborne Pathogens Standard has helped to protect Health Care Practitioner from blood exposure and sharps injuries. However, sharp injuries continue to occur and pose the risk of bloodborne pathogen transmission to Health Care Practitioners and patients. Most exposures in dentistry are preventable; therefore, each dental practice should have policies and procedures available addressing sharps safety. HCP should be aware of the risk of injury whenever sharps are exposed. When using or working around sharp devices, Health Care Practitioners should take precautions while using sharps, during cleanup, and during disposal. ⮚ Engineering and work-practice controls are the primary methods to reduce exposures to blood and OPIM from sharp instruments and needles. Whenever possible, engineering controls should be used as the primary method to reduce exposures to bloodborne pathogens. Engineering controls remove or isolate a hazard in the workplace and are frequently technology-based (e.g., self-sheathing anesthetic needles, safety scalpels, and needleless IV ports). Employers should involve those Health Care Practitioners who are directly responsible for patient care (e.g., dentists, hygienists, dental assistants) in identifying, evaluating and selecting devices with engineered safety features at least A Self-regulated Learning Module

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annually and as they become available. Other examples of engineering controls include sharps containers and needle recapping devices. ⮚ When engineering controls are not available or appropriate, work-practice controls should be used. Work-practice controls are behavior-based and are intended to reduce the risk of blood exposure by changing the way Health Care Practitioners perform tasks, such as using a one-handed scoop technique for recapping needles between uses and before disposal. Other work-practice controls include not bending or breaking needles before disposal, not passing a syringe with an unsheathed needle by hand, removing burs before disassembling the handpiece from the dental unit, and using instruments in place of fingers for tissue retraction or palpation during suturing and administration of anesthesia. ⮚ All used disposable syringes and needles, scalpel blades, and other sharp items should be placed in appropriate puncture-resistant containers located close to the area where they are used. Sharps containers should be disposed of according to state and local regulated medical waste rules.

Key Recommendations for SHARPS SAFETY: 1. Consider sharp items (e.g., needles, scalpel and other sharp objects) that are contaminated with patient blood and saliva as potentially infective and establish engineering controls and work practices to prevent injuries.

2. Do not recap used needles by using both hands or any other technique that involves directing the point of a needle toward any part of the body.

3. Use either a one-handed scoop technique or a mechanical device designed for holding the needle cap when recapping needles (e.g., between multiple injections and before removing from a non-disposable aspirating syringe).

4. Place used disposable syringes and needles, scalpel blades, and other sharp items in appropriate puncture-resistant containers located as close as possible to the area where the items are used.

(Aseptic Technique for Parenteral Medications) Safe Injection Practices ⮚ safe injection practices are intended to prevent transmission of infectious diseases between one patient and another, or between a patient and Health Care Practitioner during preparation and administration of parenteral (e.g., intravenous or intramuscular injection) medications. Safe injection practices are a set of measures Health Care Practitioner should follow to perform injections in the safest possible manner for the protection of patients. Health Care Practitioner most frequently handle parenteral A Self-regulated Learning Module

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medications when administering local anesthesia, during which needles and cartridges containing local anesthetics are used for one patient only and the dental cartridge syringe is cleaned and heat sterilized between patients. Other safe practices described here primarily apply to use of parenteral medications combined with fluid infusion systems, such as for patients undergoing conscious sedation. Unsafe practices that have led to patient harm include: 1) use of a single syringe = with or without the same needle — to administer medication to multiple patients.

2) reinsertion of a used syringe = with or without the same needle — into a Medication vial or solution container (e.g., saline bag) to obtain additional medication for a single patient and then using that vial or solution container for subsequent patients, and 3) preparation of medications in close proximity to contaminated supplies or equipment.

Key Recommendations for SAFE INJECTION PRACTICES: 1. Prepare injections using aseptic technique 2 in a clean area.

2. Disinfect the rubber septum on a medication vial with alcohol before piercing.

3. Do not use needles or syringes* for more than one patient (this includes manufactured prefilled syringes and other devices such as insulin pens).

4. Medication containers (single and multidose vials, ampules, and bags) are entered with a new needle and new syringe, even when obtaining additional doses for the same patient.

5. Use single-dose vials for parenteral medications when possible.

6. Do not use single-dose (single-use) medication vials, ampules, and bags or bottles of intravenous solution for more than one patient.

7. Do not combine the leftover contents of single-use vials for later use.

8. The following apply if multidose vials are used— a. Dedicate multidose vials to a single patient whenever possible. b. If multidose vials will be used for more than one patient, they should be restricted to a centralized medication area and should not enter the immediate patient treatment area (e.g., dental operative) to prevent inadvertent contamination. c. If a multidose vial enters the immediate patient treatment area, it should be dedicated for single-patient use and discarded immediately after use. d. Date multidose vials when first opened and discard within 28 days, unless the manufacturer specifies a shorter or longer date for that opened vial.

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9. Do not use fluid infusion or administration sets (e.g., IV bags, tubings, connections) for more than one patient.

Sterilization and Disinfection of Patient-Care Items and Devices

Disinfection Disinfectant solutions are used to inactivate any infectious agents that may be present in blood or other body fluids. ⮚ They must always be available for cleaning working surfaces, equipment that cannot be autoclaved, non-disposable items, and for dealing with any spillages involving pathological specimens or other known infectious material. ⮚ Needles and instruments should routinely be soaked in a chemical disinfectant for 30 minutes before cleaning. ⮚ Disinfection decreases the viral and bacterial burden of an instrument, but does not clean debris from the instrument or confer sterility. ⮚ Purpose of disinfection is to reduce the risk to those who have to handle the instruments during further cleaning. ⮚ Reusable needles must always be used with great care. After use, they should be placed in a special container of disinfectant before being cleaned and sterilized. ⮚ Thick gloves should be worn when needles and sharp instruments are being cleaned. ⮚ There are many disinfectant solutions, with varying degrees of effectiveness. Most widely available is sodium hypochlorite solution (commonly known as bleach or chloros), which is a particularly effective antiviral disinfectant solution. ⮚ To ensure effective disinfection, follow the manufacturer’s instructions or any other specific guidelines that have been given and dilute the concentrated solution to the correct working strength. ⮚ It is important to use all disinfectant solutions within their expiry date as some solutions, such as hypochlorite, lose their activity very quickly. ⮚ All disinfectants have a “contact time”, which means that they must be left in contact with an infectious agent for a certain period of time to ensure that it is completely inactivated.

However, some disinfectants are themselves inactivated by the presence of organic material, so higher concentrations of disinfectant and longer contact times must be used in certain situations, such as a large spill of infected blood. ⮚ Linen soiled with blood should be handled with gloves, and should be collected and transported in leak-proof bags.

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⮚ Wash the linen first in cool water, then disinfect with a dilute chlorine solution. Then wash it with detergent for 25 minutes at a temperature of at least 71°C.

Sterilization The methods of sterilization in common use are: 1. Autoclaving ⮚ Autoclaving should be the main form of sterilization at the district hospital. ⮚ Before sterilizing medical items, they must first be disinfected and vigorously cleaned to remove all organic material. Proper disinfection decreases the risk for the person who will be cleaning the instruments. ⮚ Sterilization of all surgical instruments and supplies is crucial in preventing HIV transmission. All viruses, including HIV, are inactivated by steam sterilization (autoclaving) for 20 minutes at 121°C–132°C or for 30 minutes if the instruments are in wrapped packs. ⮚ Appropriate indicators must be used each time to show that sterilization has been accomplished. At the end of the procedure, the outsides of the packs of instruments should not have wet spots, which may indicate that sterilization has not occurred.

2. Dry heat ⮚ If items cannot be autoclaved, they can be sterilized by dry heat for1–2 hours at 170°C. Instruments must be clean and free of grease or oil. ⮚ Sterilizing by hot air is a poor alternative to autoclaving since it is suitable only for metal instruments and a few natural suture materials. ⮚ Boiling instruments is now regarded as an unreliable means of sterilization and is not recommended as a routine in hospital practice.

3. Antiseptics ⮚ Sharp instruments, other delicate equipment and certain catheters and tubes can be sterilized by exposure to formaldehyde, glutaral (glutaraldehyde) or chlorhexidine. ⮚ If you are using formaldehyde, carefully clean the equipment and then expose it to vapour from paraformaldehyde tablets in a closed container for 48 hours. ⮚ Glutaral is a disinfectant that is extremely effective against bacteria, fungi and a wide range of viruses. Always follow the manufacturer’s instructions for use.

WASTE DISPOSAL IN CLINICAL PROCEDURES AT RESOURCE LIMITED HEALTH CARE FACILITY It is essential for the hospital to have protocols to deal with biological waste and contaminated materials. All staff must be familiar with them and follow them. ⮚ All biological waste must be carefully stored and disposed of safely.

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⮚ Contaminated materials such as blood bags, dirty dressings and disposable needles are potentially hazardous and must be treated accordingly. ⮚ If biological waste and contaminated materials are not disposed of properly, staff and members of the community could be exposed to infectious material and become infected. · Disposal of bio hazardous materials is time consuming and expensive, so it is important to separate noncontaminated material such as waste paper, packaging and non-sterile but not biologically contaminated materials. (Only 15% to 20% of medical wastes are considered infectious). ⮚ Make separate disposal containers available where waste is created so that staff can sort the waste as it is being discarded. A three-color coding system with black for noninfectious waste, red or yellow for infectious and yellow for sharps is recommended. ⮚ Organize things in a way to discourage the need for people to be in contact with contaminated waste. ⮚ All infected waste should then be treated off by steam sterilization or high temperature incineration equipped with emission control devices. Whenever feasible plastic material such as syringes or blood bags should not be incinerated. ⮚ Burying waste is the only option in some areas where not controlled landfill exists. If this is the case, you should do as much as possible to protect the burying site to prevent access and to avoid environmental pollution, especially for underground water sources. ⮚ Prior to burying, for safety infected waste can be disinfected by soaking in a 0.5% hypochlorite solution for at least 30 minutes. ⮚ Do not mix waste chemicals, unless you are certain that a chemical reaction will not take place. This is essential to prevent any unwanted or dangerous reactions between the chemicals, which could endanger laboratory staff. ⮚ Always follow local guidelines on the disposal of waste chemicals to avoid any chemical contamination of the surrounding land or water supply. ⮚ Provide a safe system for getting rid of disposable items such as scalpel blades or needles. The risk of injury with sharp objects increases with the distance they are carried and the amount they are manipulated. ⮚ A container for the safe disposal of sharp objects should be: § Well labelled § Puncture proof, Watertight § Break resistant (a glass container could break and provide a serious hazard to the person cleaning up) § Opening large enough to pass needles and scalpel blades, but never large enough for someone to reach in § Secured to a surface, such as a wall or counter, to ensure stability during use § Removable for disposal. ⮚ These containers must then be disposed of safely. (They can be steam sterilized, then shredded and disposed of to a controlled land fill with municipal waste, encapsulated in a pit or any other options according to national protocols approved by the public health department and ministry of environment.)

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⮚ Health-care workers and waste handlers should wear protective equipment such as gloves, apron, mask and be immunized against HBV. ⮚ A budget line for a safe waste management should be systematically included when planning a medical activity.

Categories of Health Care Waste 1) General Waste – this type of waste does not pose special handling problem or hazard to human health or to the environment. It comes most from the administrative and housekeeping functions of health care establishments and may also include waste generated during maintenance of health care premises.

2.) Infectious Waste – this type of waste is suspected to contain pathogens (bacteria, viruses, parasites, or fungi) in sufficient concentration or quantity to cause disease in susceptible hosts. This includes: o

Cultures and stocks of infectious agents from laboratory work;

o

Waste from surgery and autopsies on patients with infectious diseases (e.g. tissues, materials or equipment that have been in contact with blood or other body fluids)

o

Waste from infected patients in isolation wards (e.g. excreta, dressings from infected or surgical wounds, clothes heavily soiled with human blood or other body fluids);

o

Waste that has been in contact with infected patients undergoing haemodialysis (e.g. dialysis equipment such as tubing and filters, disposable towels, gowns, aprons, gloves, and laboratory coats);

o

Infected animals from laboratories; and

o

Any other instruments or materials that have been in contact with infected persons or animals.

3) Pathological Waste - consists of tissues, organs, body parts, human fetus and animal carcasses, blood and body fluids. Within this category, recognizable human or animal body parts are also called anatomical waste. This category should be considered as a subcategory of infectious waste, even though it may also include healthy body parts.

4) Sharps - Include needles, syringes, scalpels, saws, blades, broken glass, infusion

sets, knives, nails and any other items that can cause a cut or puncture wounds.

Whether or not they are infected, such items are usually considered as highly hazardous health care waste.

5) Pharmaceutical waste - Includes expired, unused, spilt, and contaminated

pharmaceutical products, drugs, vaccines, and sera that are no longer required and need to be disposed of appropriately. This category also includes discarded items used in handling of pharmaceuticals such as bottles or boxes with residues, gloves, masks, connecting tubing and drug vials.

6) Genotoxic Waste - Genotoxic waste may include certain cytostatic drugs, vomit,

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urine, or feces from patients treated with cytostatic drugs, chemicals, and radioactive materials. This type of waste is highly hazardous and may have mutagenic, teratogenic, or carcinogenic properties.

Harmful cytostatic drugs can be categorized as follows: a. Alkylating agents: cause alkylation of DNA nucleotides, which leads to cross-linking and miscoding of the genetic stock; b. Anti-metabolites: inhibit the biosynthesis of nucleic acids in the cell; mitotic inhibitors: prevent cell replication Cytotoxic wastes are generated from several sources and include the following: c. Contaminated materials from drug preparation and administration, such as syringes, needles, gauges, vials, packaging; outdated drugs, excess (left over) solutions, and drugs returned from the wards; d. Urine, feces, and vomit from patients which may contain potentially hazardous amounts of the administered cytotoxic drugs or of their metabolites and which should be considered genotoxic for at least 48 hours and sometimes up to 1 week after drug administration.

7) Chemical Waste - Chemical waste consists of discarded solid, liquid, and

gaseous chemicals, for example from diagnostic and experimental work and from cleaning, housekeeping, and disinfecting procedures. Chemical waste from health care may be hazardous or non-hazardous.

Chemical waste is considered hazardous if it has at least one of the following properties: a. b. c. d. e.

Toxic Corrosive (e.g. acids of pH <2 and bases of pH >12) Flammable Reactive (explosive, water-reactive, shock-sensitive) Genotoxic (e.g. cytostatic drugs)

Non-hazardous chemical waste consists of chemicals with none of the above properties, such as sugars, amino acids, and certain organic and inorganic salts.

8) Waste with high content of heavy metals - represent a subcategory of

hazardous chemical waste, and are usually highly toxic. Mercury wastes are typically generated by spillage from broken clinical equipment (thermometers, blood pressure gauges, etc.). Whenever possible, spilled drops of mercury should be recovered.

9) Pressurized Containers - Many types of gas are used in health care and are

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are reusable, but certain types notably aerosol cans, must be disposed of.

Whether inert or potentially harmful; gases in pressurized containers should always be handled with care; containers may explode if incinerated or accidentally punctured.

Radioactive Waste – Includes disused sealed radiation sources, liquid and gaseous materials contaminated with radioactivity, excreta of patients who underwent radio- nuclide diagnostic and therapeutic applications, paper cups, straws, needles and syringes, test tubes, and tap water washings of such paraphernalia. It is produced as a result of procedures such as in vitro analysis of body tissues and fluids, in vivo organ imaging, tumor localization and treatment, and various clinical studies involving the use of radioisotopes.

10)

ACTIVITY TIME

Proper waste disposal: List down the different color-coded waste bag and list down the proper waste that are on every color. (Philippine setting) COLORS

WASTE PRODUCTS

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Choose the best Question 1. NO A. When should you wash hands with soap and water?

B. What is the principle underlying standard Precautions?

C. What are the Five Moments for hand hygiene?

D. How is Hand Hygiene required with glove use?

2. Sterile gloves A. What kind of gloves must be used for surgical procedures?

B. What is the principle underlying Standard Precautions?

C. How many times should we moisturize our skin at work?

D. What are the two zones in your working environment?

3. Waiting area, group-based therapy.

A. When should you use alcohol-based hand rub?

B. What is Hand Hygiene?

C. Give a few examples of a Shared Patient Area?

D. What are the two zones in your working environment?

4. Three times a shift.

A. What are the two zones in your working environment?

B. When performed correctly what does hand hygiene results in?

C. How many times should we moisturize our skin at work?

D. What kind of gloves must be used for surgical procedures?

5. practices used to remove or destroy pathogens and to prevent their spread from one Person or place to another person or place; clean technique.

A. medical asepsis B. asepsis C. disinfection D. exogenous infection 6. is caused by microorganisms that are not normal body flora; from outside the body.

A. iatrogenic infection B. exogenous infection C. endogenous infection D. nosocomial 7. Infections caused by a treatment or diagnostic procedure.

A. endogenous infection B. nosocomial infection C. iatrogenic infection D. exogenous infection 8. Lack of resistance to disease A. susceptibility B. bacteriocidal C. medical asepsis D. nosocomial infection A Self-regulated Learning Module

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9. The control of spread of ____________from the source is key to avoid transmission.

A. good vibes B. flora C. pathogens D. Virus 10. Promotion of a __________is a cornerstone of prevention of transmission of pathogen in health care.

A. health teaching B. safety climate C. family planning D. reading 11. this reduces the transmission of airborne infection → It is appropriate to "sneeze into your sleeve" because A. True B. False C. maybe D. none of the above 12. clearly contributed to SARS coronavirus transmission. → The need for cough etiquette recommendations stemmed from recent severe acute respiratory syndrome (SARS) outbreaks, where failure to observe simple source-control measures A. True B. False C. maybe D. none 13.

Cover -

mouth

and

Dispose

nose

w/

a

tissue

of

when used

cough/sneeze tissue

- Perform hand hygiene → 2. Availability of Supples A. True B. False C. maybe D. none 14. it is important to education... about cough etiquette → patients and families A. True B. False C. maybe D. none 15. respiratory hygiene applies to ... → anyone entering a healthcare setting; patients, visitors, and staff with signs or sxs of illness, whether diagnosed or undiagnosed including cough, congestion, rhinorrhea, or increased production of respiratory secretions A. True B. False A Self-regulated Learning Module

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C. maybe D. none 16. Which sharps safety technique is accurate?

A. Using an automatic needle re-sheathing device B. Dispose of used needles at chairside, instead of in the sterilization room.

C. New employees spend the first 3 days in safety training before training in other areas.

D. A “Culture of Safety” will reflect in the attitudes and behaviors of the Personnel 17. Which is NOT a feedback system, used to communicate safety?

A. News letter B. bulletin board C. Safety Pledge D. Meeting Agenda 18. Instrument processing injuries are associated with A. Infection B. Hepatitis C (HCV) C. Long-handled brush D. needle recapping 19. Sharps safety procedures indicate what type of gloves should be worn during operatory cleanup and instrument processing?

A. Nitrile examination gloves B. Utility gloves C. Latex examination gloves D. Sterile gloves 20. Which measure is designed to prevent a sharps-related injury?

A. Fill the sharps containers only ¾ full.

B. Wear vinyl operatory gloves during post-operatory clean up.

C. Organize sharp instruments in the cassette, with tips pointing upward.

D. Remove and discard the needle before discarding a disposable syringe.

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Biomedical Waste Management

⮚ biomedical waste poses physical, chemical, radiological, and microbiological risks to the public and health-care workers (HCWs) for current and future generations.

Bio-medical Waste ⮚ means any waste, which is generated during the diagnosis, treatment or immunization of human beings or animals or in research activities pertaining there to or in the production of testing of biological.

Hazardous Waste ⮚ Any waste with a potential to pose a threat to human health and life.

Categories of Biomedical Waste

1) General Waste - Comparable to domestic waste, this type of waste does not pose special handling problem or hazard to human health or to the environment. It comes mostly from the administrative and housekeeping functions of health care establishments and may also include waste generated during maintenance of health care premises. General waste should be dealt with by the municipal waste disposal system.

2) Infectious Waste – This type of waste is suspected to contain pathogens (bacteria, viruses, parasites, or fungi) in sufficient concentration or quantity to cause disease in susceptible hosts. This includes: ● Cultures and stocks of infectious agents from laboratory work; ●

Waste from surgery and autopsies on patients with infectious diseases (e.g. tissues, materials or equipment that have been in contact with blood or other body fluids);

●

Waste from infected patients in isolation wards (e.g. excreta, dressings from infected or surgical wounds, clothes heavily soiled with human blood or other body fluids);

●

Waste that has been in contact with infected patients undergoing haemodialysis (e.g. dialysis equipment such as tubing and filters, disposable towels, gowns, aprons, gloves, and laboratory coats);

●

Infected animals from laboratories; and

●

Any other instruments or materials that have been in contact with infected persons or animals.

3) Pathological Waste - Pathological waste consists of tissues, organs, body

parts, human fetus and animal carcasses, blood and body fluids. Within this A Self-regulated Learning Module

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category, recognizable human or animal body parts are also called anatomical waste. This category should be considered as a subcategory of infectious waste, even though it may also include healthy body parts.

4) Sharps - Include needles, syringes, scalpels, saws, blades, broken glass,

infusion sets, knives, nails and any other items that can cause a cut or puncture wounds. Whether or not they are infected, such items are usually considered as highly hazardous health care waste.

5) Pharmaceutical waste - Includes expired, unused, spilt, and contaminated

pharmaceutical products, drugs, vaccines, and sera that are no longer required and need to be disposed of appropriately. This category also includes discarded items used in handling of pharmaceuticals such as bottles or boxes with residues, gloves, masks, connecting tubing and drug vials.

6) Genotoxic Waste - Genotoxic waste may include certain cytostatic drugs,

vomit, urine, or feces from patients treated with cytostatic drugs, chemicals, and radioactive materials. This type of waste is highly hazardous and may have mutagenic, teratogenic, or carcinogenic properties.

Harmful cytostatic drugs can be categorized as follows: ●

Alkylating agents: cause alkylation of DNA nucleotides, which leads to cross-linking and miscoding of the genetic stock;

●

Anti-metabolites: inhibit the biosynthesis of nucleic acids in the cell; mitotic inhibitors: prevent cell replication

Cytotoxic wastes are generated from several sources and include the following: ●

Contaminated materials from drug preparation and administration, such as syringes, needles, gauges, vials, packaging; outdated drugs, excess (left over) solutions, and drugs returned from the wards;

Urine, feces, and vomit from patients which may contain potentially hazardous amounts of the administered cytotoxic drugs or of their metabolites and which should be considered genotoxic for at least 48 hours and sometimes up to 1 week after drug administration.

7) Chemical Waste - Chemical waste consists of discarded solid, liquid, and

gaseous chemicals, for example from diagnostic and experimental work and from cleaning, housekeeping, and disinfecting procedures. Chemical waste from health care may be hazardous or non-hazardous.

Chemical waste is considered hazardous if it has at least one of the following properties: A Self-regulated Learning Module

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● ● ● ● ●

Toxic Corrosive (e.g. acids of pH <2 and bases of pH >12) Flammable Reactive (explosive, water-reactive, shock-sensitive) Genotoxic (e.g. cytostatic drugs)

Non-hazardous chemical waste consists of chemicals with none of the above properties, such as sugars, amino acids, and certain organic and inorganic salts.

8) Waste with high content of heavy metals - Wastes with a high heavy-metal

content represent a subcategory of hazardous chemical waste, and are usually highly toxic. Mercury wastes are typically generated by spillage from broken clinical equipment (thermometers, blood pressure gauges, etc.).

Whenever possible, spilled drops of mercury should be recovered.

9) Pressurized Containers - Many types of gas are used in health care and are

often stored in pressurized cylinders, cartridges, and aerosol cans. Many of these, once empty or of no further use (although they may still contain residues), are reusable, but certain types notably aerosol cans, must be disposed of. Whether inert or potentially harmful; gases in pressurized containers should always be handled with care; containers may explode if incinerated or accidentally punctured.

10) Radioactive Waste – Includes disused sealed radiation sources, liquid and

gaseous materials contaminated with radioactivity, excreta of patients who underwent radio- nuclide diagnostic and therapeutic applications, paper cups, straws, needles and syringes, test tubes, and tap water washings of such paraphernalia.

SOURCES: Sources of health care waste include health care facilities, institutions, business establishments and other similar health care services with activities or work processes that generate / produce health care waste. Below are examples of facilities that generate health care waste: 1) Hospitals 2) Clinics

Medical Veterinary Health care centers and dispensaries Alternative medicine

   

Dental Maternity and Lying-in Dialysis centers Physician Offices

3) Laboratories and Research Centers

Medical and biomedical laboratories Medical research centers and institutions Blood banks and blood collection services

 Biotechnology laboratories  Animal research and testing  Nuclear medicine laboratories

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4) Drug Manufacturers 5) Institutions

 Nursing  Drug rehabilitation centers  Veterinary

Medical Nursing homes Dental Paramedics 6) Mortuary and Autopsy Centers 7) Ambulances and Emergency Care

8) Home Treatment (e.g. Dialysis, Insulin injection, etc.)

9) Cosmetic Ear Piercing and Tattoo Parlors

COMPOSITION: The type of source often characterizes the composition of wastes.

For example, the different units within the health care establishment would generate waste with the following characteristics: ☞ Medical Wards ☞ Operating theaters and surgical wards ☞ Other health care units ☞ Laboratories ☞ Pharmaceutical and chemical stores ☞ Support Units Health care waste from other sources generally has the following composition: ☞ Health care provided by nurses ☞ Physician's offices ☞ Dental clinics and dentist's offices ☞ Home health care (e.g. dialysis, insulin injections) Waste Management/Waste Minimization Health care waste minimization is centered on the elimination or reduction of the health care waste stream. There are several measures that can be instituted to achieve waste minimization including the following: 1. Reduction at source 2. Re-use 3. Recycling 4. Segregation of Waste 5. Composting Implementing Waste Minimization Strategies: ● Applying health care waste minimization strategies to specific areas of the facility ●

Tracking the waste minimization efforts and comparing the results with the waste data gathered during the assessment phase of the program

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●

Evaluating the waste minimization process to document success, determine training efficiency and needs

●

Instituting policy directives incorporating improved health care waste minimization processes

●

Planning new health care waste minimization pilot projects for further waste reduction.

Examples of Policies and Practices that Encourage Waste Minimization: Reduction of Waste at Source  Purchase/select supplies and materials that are less wasteful and less hazardous  Use less hazardous method in cleaning (e.g. steam disinfection instead of chemical disinfection) Management and control measures at hospital level  Centralized purchasing of hazardous chemicals  Monitoring of chemical flows within the health facility from receipt as raw materials to disposal as hazardous waste Stock management of chemical and pharmaceutical products  Systematize use of product “first in, first out (FIFO)”  Frequent ordering of relatively small quantities rather than large amounts at one time (applicable in particular to unstable products/unpredictable consumption rate)  Use all the contents of each container  Checking of the expiry date of all products at the time of delivery and based on its optimum consumption rate.

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Quick Quiz 1. Chemicals like sodium hypochlorite, hydrogen peroxide, peroxyacetic acid, and heated alkali are added. Recommendation is bleach (sodium hypochlorite) with 5% concentration be used. Disadvantage of this method is that it generates chemical wastes.

A. Healthcare wastes B. Chemical Disinfection C. Bleach (sodium hypochloride) D. Impact of Infectious waste and sharps

2. Health-care workers, other hospital workers, waste-management operators outside health-care establishments, and individuals who scavenge on waste disposal sites are at significant risk of blood-borne infections (through sharps).

A. Impact of infectious waste and sharps B. Categories of healthcare wastes C. Impact of chemical and pharmaceutical waste D. Impact of genotoxic waste 3. Strong leak-proof bin. Liner is yellow with black band plastic with 0.009mm thickness A. Healthcare wastes B. waste generator C. Pathological and Anatomical wastes D. Pharmaceutical Waste 4. If no access to landfills, disposal is usually done through? This is only applicable to treated infectious wastes, sharps, pathological and anatomical wastes and only allowed in health care facilities located in remote areas.

A. Infectious waste B. Safe Burial C. radioactive waste D. Segregation 5. Filling of containers with waste and sealing the containers. Uses either cubic boxes made of high-density polyethylene or metallic drums, that are threequarters filled with sharps, or chemicals, or pharmaceutical residues. Then filled up with a medium such as plastic foam, bituminous sand, and cement mortar to immobilize. It is then disposed of in a landfill.

A. Segregation B. Safe burial C. Encapsulation D. Infectious waste

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6. This category should be considered as a subcategory of infectious waste, even though it may also include healthy body parts.

A. General Waste B. Pharmaceutical Waste C. Segregation D. Pathological waste 7. This type of waste is highly hazardous and may have mutagenic, teratogenic, or carcinogenic properties A. Sharps B. Chemical Waste C. Genotoxic Waste D. Pharmaceutical waste 8. This waste is flammable, toxic and corrosive.

A. Sharps B. Chemical Waste C. Genotoxic Waste D. Pharmaceutical waste 9. General Waste A. It comes mostly from the administrative and housekeeping functions of health care establishments and may also include waste generated during maintenance of health care premises.

B. Any other instruments or materials that have been in contact with infected persons or animals.

C. Includes expired, unused, spilt, and contaminated pharmaceutical products, drugs, vaccines, and sera that are no longer required and need to be disposed of appropriately.

D. inhibit the biosynthesis of nucleic acids in the cell; mitotic inhibitors: prevent cell replication 10. Pressurized Containers A. health care wastes generally contain radionuclides with short half-lives, which lose their activity in a shorter time.

B. Mercury wastes are typically generated by spillage from broken clinical equipment (thermometers, blood pressure gauges, etc.).

C. Residues from dentistry have high mercury content.

Cadmium waste comes mainly from discarded batteries.

D. Many types of gas are used in health care and are often stored in pressurized cylinders, cartridges, and aerosol cans.

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11. Operating theatres and surgical wards general wastes includes: (Enumerate) A. B. C. D. E.

Role of a nurse to hospital acquired Infections Nurses play a pivotal role in preventing hospital-acquired infections (HAI), not only by ensuring that all aspects of their nursing practice are evidence based, but also through nursing research and patient education.

As patient advocates, nurses are in the unique position to affect change to improve patient care standards Universal precautions are the cornerstones of a safe environment that is free of infection. According to the Center for Disease Control and Prevention (CDC, 2010) universal precautions are designed to prevent the transmission of blood borne pathogens when providing first aid or healthcare. They apply to a wide variety of; > body fluids > amniotic fluids > including blood > semen > cerebrospinal fluid > vaginal secretions They do not apply to: > nasal secretions > sweat > feces > sputum > tears > vomit > urine (unless these fluids contain visible blood) > saliva Role of Nursing Personnel in prevention of Hospital Acquired Infections: → Nursing background helps her in her job with infection control → The physician might be more in tune with a disease and its process → The nurse is probably more in tune to hospital policy development and compliance would like to see → More programs that educate nurses in epidemiology are required → This area has no formal learning track, and a recent increase in emerging and re-emerging infectious diseases will make the field all the more important.

There are many other ways in which nurses can prevent infection at the bedside.

Avoidance of urinary catheterization is recommended whenever possible.

Hand washing is another potent weapon in the nurse’s arsenal against infection, and is the single most important nursing intervention to prevent infection. Effective hand A Self-regulated Learning Module

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washing may be accomplished with antimicrobial soap and water, and specific guidelines are provided by the CDC for the use of alcohol-based hand rubs as acceptable substitutes.

For patients who require long-term catheterization, supra-pubic catheters should be considered. Scrupulous hand washing and aseptic technique is vitally important in the insertion and care of urinary catheters, as well as accurate and precise documentation.

Intravenous therapy is a huge area of concern with HAIs. Nurses can make a huge contribution in this war against infection by using full barrier precautions (sterile field, caps, gowns, masks and gloves) when preparing for the insertion of central venous catheters. All catheters, regardless of site, should always be placed aseptically.

A two percent chlorhexidine preparation is the preferred cleansing agent of catheter sites and injection ports and diaphragms of multidose vials should be cleansed with 70 percent alcohol prior to accessing (CDC, 2010). Catheters should be removed promptly when deemed unnecessary.

In addition to practical bedside interventions, nurses can foster a safe environment for patients by creating an open, non-punitive environment where errors and near misses can be reported. This approach helps an organization determine how to improve the system and prevent future errors from occurring. Become familiar with your organization’s error reporting policies, procedures and keep in mind the following general tips: ●

Adopt a safety-minded attitude. Safety is everybody’s job! Make prevention a part of your work habits.

●

Focus on the task at hand.

●

When “noise” in your environment is distracting, you and others are at risk for accidents.

●

Noise” might include your own thoughts that are unrelated to the task at hand, an interesting conversation going on nearby, or anything that breaks your concentration.

●

Identify “noise” and take actions to limit the source.

●

Develop a personal list-making or note-taking system to keep your thoughts focused.

Nurses in all roles and settings can demonstrate leadership in infection prevention and control by using their knowledge, skill and judgment to initiate appropriate and immediate infection control procedures. Practice diligently and keep your patient safe.

Function of the Infection Control Nurse: o Experienced nurses are appointed full time on this position. o Regular visit to all wards and high risk units. o Checking nursing supervisor’s register and records suggestive of infection. o Collection and tabulation of daily data of incidence of hospital infection.

- Identification and location of pt.

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o o

o o o o

- Date of admission - Date of infection - Type of infection - Cultures taken, antibiotics taken - Name of treating physician Ensuring that samples (blood, stool, urine, swab etc.) are collected and dispatched to laboratory in time.

Initiating the hospital infection control form while documenting nosocomial infections, the registration form used should be different from the routine investigation forms, so that minimum time is wasted in getting the culture and sensitivity reports.

Compilation of ward wise, discipline wise or procedure wise statistics.

Daily visit to microbiology laboratory to ascertain results of samples collected for Surveillance and to liase between microbiology and clinical departments.

Monitoring and supervision of infection among hospital staff.

Training of nursing aides and paramedical personnel on correct hygiene practices and aseptic techniques.

Hospital Infection Control Program

What is infection Control? ⮚ Is the discipline concerned with preventing nosocomial or health careassociated infection. As such, it is a practical (rather than an academic) Subdiscipline of epidemiology. It is an essential (though often under-recognized and under-supported) part of the infrastructure of health care. Infection control and hospital epidemiology are akin to public health practice, practiced within the confines of a particular health-care delivery system rather than directed at society as a whole.

Beginning of Hospital Infection Programme: = Modern hospital infection control programs first began in the 1950s in England, where the primary focus of these programs was to prevent and control hospital-acquired staphylococcal outbreaks. In 1968, the American Hospital Association published “Infection Control in the Hospital” the first and only standards available for many years.

Objectives: ▪ ▪ ▪ ▪

The main objectives of these guidelines is to prevent the health care workers and the environment from the transmission of infections: Facilities, equipment, and procedures necessary to implement standard precautions.

Cleaning, disinfecting and reprocessing of reusable equipment.

Waste management, prevention of HAI in patients.

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Steps to Effective Hospital Infection Programs 1.

Educate Staff = Effective infection control requires continual staff education on correct practices and the organization's infection control policies. Hospitals should educate staff during orientation and throughout the year as needed, such as when new policies are instituted.

Example: all staff need to be taught the importance and appropriate technique of hand hygiene. In addition, medical staff should be educated about appropriate antibiotic use. "Teach staff how to use antibiotics prudently and not to overuse antibiotics.

2. Create a multidisciplinary team = A hospital's infection control committee should be a multidisciplinary group. A committee personnel should include the hospital epidemiologist, infection preventionists, a microbiologist and representatives from the main hospital departments. IT and secretarial support are also essential. "Creating a multidisciplinary team also enables hospitals to develop sub-committees or special task forces to solve a specific problem," 3. Collect data = is the initial step in the surveillance function performed by infection preventionists. It is important to establish baseline rates for surgical site and bloodstream infections, ventilator associated pneumonia, urinary tract infections and others as needs arise. "One way of doing surveillance of infections is targeted surveillance — choosing certain areas where there could be a high risk of healthcareassociated infections". The team should also work with the microbiology lab to determine the facility's endogenous bacteria and to identify antibiotic susceptibilities and resistance patterns — including multiple drug-resistant bacteria.

4. Analyze the data = The next step is to analyze the data for trends and risks. South Nassau Communities Hospital's Infection Control committee meets nine times a year to formally review data reports, but the infection preventionists review data daily to check for unusual trends or clusters of infection.

Example: If an increase in bloodstream infections is noted, they would immediately analyze the data in detail to identify any potential causes. They would identify the type of cases that had bloodstream infections, the time period, the area of the hospital where the infections were reported, the physicians and other staff members who managed the case and any other factors that could correlate with the infection 5. Communicate the data = The infection control department needs to communicate surveillance data to staff to ensure awareness of any issues. Data is communicated by several methods at South Nassau Communities Hospital. After the infection control committee meetings, the department representatives communicate the data they learned to their respective staff members.

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well as to the medical board of the hospital. In addition, the infection preventionists make daily rounds on the hospital units and communicate any important or new information to staff at that time. Lectures and emails are also used to keep the staff up-to-date.

6. Develop action plans = When the team identifies an increase in infections or risks of increased infections through data analysis, members meet to develop action plans. "Hospitals have to maintain vigilance for problems and develop action plans as problems arise,".

Example: in the case of bloodstream infections, the hospital may choose to start using silver-coated central IV catheters, create a central line insertion kit and ascertain that procedures for IV placement are standardized. Analysis of data collected through surveillance therefore enables the hospital to improve practice and procedures. "It also results in increased consciousness of what we're doing,".

7. Additional activities of the infection control department = Such activities include monitoring hand hygiene, monitoring sterilization and disinfection practices/sterilizer function, monitoring negative pressure rooms and performing infection control risk analyses for all hospital construction projects.

8. Stay up-to-date on policies and news = infection control staff be continually aware of news and updates from organizations such as CDC, The Society for Healthcare Epidemiology of America, the Association for Professionals in Infection Control and Epidemiology, the Infectious Diseases Society of America, as well as state and local health departments. One must stay connected and be aware of infections in the community or nationwide that could enter the hospital.

Developing Infection Control Programme: Every infection control program should develop a well- defined written plan outlining the organizational philosophy regarding infection prevention and control. The plan should take into account the goals, mission statement, and an assessment of the infection control program. It should include a statement of authority, and should review patient demographics including geographic locations of patients served by the healthcare system.

Components of Infection Control Program 1. Basic measures for infection control-standard and additional precaution.

2. Education and training of health care workers.

3. Identification of hazards and minimizing risks.

4. Protection of health care workers 5. Aseptic techniques 6. Use of single use device, reprocessing of instrumental and equipment.

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7. Antibiotic usage, management of body/ blood fluid, exposure handling of blood/blood product and hospital waste management.

8. Surveillance 9. Outbreak investigation 10. Incident monitoring SURVEILLANCE: •

The surveillance is the cornerstone of the infection control practice because it allows to identify the areas where the outcomes are below expectations and we can improve.

Examples surveillance.

•

of

centrally

driven

surveillance

include

MRSA

bacteremia

The key to ongoing monitoring is surveillance for nosocomial infections. Various techniques for surveillance have been described and evaluated including total house surveillance targeted.

KEY ELEMENTS of SURVEILLANCE: ☞ Defining as precisely as possible the event to be surveyed (case definition) ☞ Collecting the relevant data in a systematic, valid way ☞ Consolidating the data into meaningful arrangements ☞ Analyzing and interpreting the data STAFF TRAINING IN INFECTION CONTROL PROGRAM: ☞ Education programs for employees and volunteers are one method to ensure competent infection control practices. It is unique challenge since employees represent a wide range of expertise and educational background. The Infection Control Program must become knowledgeable in adult education principles and use educational tools and techniques that will motivate and sustain behavioral change.

ORGANIZING for INFECTION CONTROL: •

•

Requires cooperation, understanding and support of hospital administration and medical/surgical/nursing leadership There is no simple formula: - Every facility is different - Every facility’s problems are different - Every facility’s personnel are different • The facility must develop its own unique program.

INFECTION CONTROL PROGRAMME and DOCUMENTATION • Goals of the infection control program need to be incorporated into the facility. A mission statement should tell who you are, what you do, and should communicate a clear view of purpose and set a strategy for accomplishing the goal.

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Infection Control Team: Consist of: > Infection control practitioner who should be trained for the purpose. > Carry out the surveillance programme >develop and disseminate infection control policies > monitor and manage critical incidents > coordinate and conduct training activities. > Physicians to be more involved and lead quality improvement efforts in there respective healthcare settings Major Responsibilities of Infection Control Programme: ☞ The major responsibilities for ICPs to oversee include surveillance, specific environmental monitoring, continuous quality improvement, consultation, committee involvement, outbreak and isolation management, regulatory compliance and education.

To plan, coordinate, and succeed in fulfilling these responsibilities, many ICPs have to redefine their roles. More ICPs are becoming managers by creating multidisciplinary support teams to carry out many of the functions.

Scientific Documentation Reduces Hospital Infections: •

The major responsibilities for ICPs to oversee include surveillance, specific environmental monitoring, continuous quality improvement, consultation, committee involvement, outbreak and isolation management, regulatory compliance and education. To plan, coordinate, and succeed in fulfilling these responsibilities, many ICPs have to redefine their roles. More ICPs are becoming managers by creating multidisciplinary support teams to carry out many of the functions.

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Follow up Quiz 1. A client is diagnosed with methicillin resistant staphylococcus aureus pneumonia.

What type of isolation is MOST appropriate for this client?

A. Respiratory Isolation B. Contact Isolation C. Standard Precautions D. Reverse Isolation 2. Several clients are admitted to an adult medical unit. The nurse would ensure airborne precautions for a client with which of the following medical conditions?

A. A positive PPD with an abnormal chest x-ray B. Advance carcinoma of the lung C. A tentative diagnosis of viral pneumonia D. A diagnosis of AIDS and cytomegalovirus 3. Which of the following is the FIRST priority in preventing infections when providing care for a client?

A. Wearing goens and goggles B. Wearing gloves C. Hand washing D. Using a barrier between client’s furniture and nurse’s bag 4. What percentage of patients develop a hospital acquired infection HAI? A. 4 % B. 5% C. 6% D. 7% 5. What does HAI stand for?

A. Health Assistant Institution B. Health Acquired Illness C. Hospital Acquired Infection D. Hospital Association Infection

6. Infections can be categorized by A. Where they originate B. Acquired from someone C. Acquired from environment D. Where pathogen came 7. When do you want to use sterile gloves?

A. When doing a chart B. When signing a from C. when transferring an IV pole A Self-regulated Learning Module

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D when contact with patient; drawing blood 8. What is an example of droplet disease/condition?

A. Urinary tract infection B. Influenza C. Head ache D. Inflammation 9. What is it common for infection prevention programs to do?

A. Record the environmental air saturation B. Report the counts of hospital cases C. Oversee hand hygiene and standard precautions adherence observations.

D. Creating a good environment for a certain disease program supervised by WHO. 10. What issues occur with disposable equipment?

A. Expensive material B. Quantity of production C. Demand of recent diseases D. Quality concern 11. What is disinfection?

A. Process of destroying at least the vegetative phase of pathogenic microorganisms by physical or chemical means.

B. the process of making something free from bacteria or other living microorganisms.

C. the process or technique of cooking food by heating it in steam from boiling water.

D. process by which a liquid turn into a vapor when it is heated to its boiling point.

12. The home, the hospital, a skilled nursing facility, or an outpatient treatment Center.

A. What is an airborne infection isolation?

B. Patients can receive care in what settings?

C. What does chemical disinfection involve?

D. What percentage of patients is this> 13. Face Shield A. in droplet precautions, your standard precautions needs to have: B. What are some examples of hand hygiene?

C. What is the minimum time that OSHA requires you to do hand wash?

D. If a patient no longer needs the ventilator; what should you do?

14. - there’s more area - its fluid and the moisture, room temperature and bacteria grow in it A. What is common for infection prevention programs to do?

B. What is an Airborne Infection Isolation?

C. Why should a large volume nebulizer be a good source of infections?

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D. three elements that must present for infection to spread.

15. How do infection prevention programs endorse prevention?

A. Some diseases transmitted directly and indirectly through environmental control.

B. By ensuring that caregivers have appropriate time, equipment, and training to provide best possible care C. The three elements that must be present for infection to spread are air, earth and fire.

D. Through the common infection channeling program of the foreign agencies.

COMPLETE THE CHAIN of INFECTION:

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Microbiological Assay of Antibiotics The microbiological assay of an antibiotic is based upon a comparison of the inhibition of growth of micro-organisms by measured concentrations of the antibiotics under examination with that produced by known concentrations of a standard preparation of the antibiotic having a known activity.

Inhibition of growth of micro-organisms by measured concentrations of the Antibiotics Effect that produced by known concentration of a standard preparation of the antibiotic having a known activity Two general Methods are usually employed: 1. The cylinder-plate (or cup-plate) method 2. The turbidimetric (or tube assay) method STEPS:

The cylinder-plate (or cup-plate) method:

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BACTERIA • •

All bacteria are unicellular organisms that reproduce by binary fission.

Bacterial cells are extremely small and are most conveniently measured in microns.

Classification of Bacteria ▪ Shapes • Cocci – Spherical or Round Shaped • Bacilli – Rod Shaped • Vibrios – Comma Shaped • Spirilla – Spiral Shaped ▪

Gram Stain • Gram Positive - Retain Primary Colour (Blue) • Gram Negative - Retain Secondary Colour (Pink)

▪ ▪

Aerobes – Require Oxygen for growth Gram Positive Aerobes – Cocci – Staphylococcus aureus – Streptococcus pneumoniae – Enterococcus Gram Positive Aerobes – Bacilli – Corynebacterium – Listeria Gram Negative Aerobes – Cocci – Neissaria gonorrhoea – Moraxella catarrhalis Gram Negative Aerobes – Bacilli – E coli – Enterobacter – Klebsiella – Proteus – Pseudomonas – H influenza – Salmonella – Shigella – H pylori

▪ ▪ ▪

▪ ▪

Anaerobes – Grow in absebce of Oxygen Gram Positive Anaerobes – Bacilli – Clostridium tetani – Lactobacilli ▪

Gram Negative Anaerobes – Cocci – Veillonella

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▪

Gram Negative Anaerobes – Bacilli – Bacteroides fragilis – Fusobacterium

▪

Atypical Organisms -Microorganisms that have undergone greater changes than normal in morphology, physiology, or cultural characteristics – Mycoplasma – Chlamydia – Ureaplasma

▪

Acid Fast Bacilli - Bacteria that are not decolorized by acid-alcohol after having been stained with dyes such as basic fuchsin.

– Mycobacterium tuberculosis

INFECTIONS: ▪

It is defined as the successful invasion and multiplication of micro-organisms in body tissues.

SOURCES of INFECTION in MAN A) MAN > Carrier = the person who harbors the pathogenic micro-organisms without suffering any ill effects from it.

• Healthy Carrier • Convalescent Carrier • Temporary Carrier • Chronic Carrier B) ANIMALS C) INSECTS D) SOIL and WATER E) FOOD METHOD of TRANSMISSION 1.) Contact Contact can be be direct: Ex: Syphilis, Gonorrhea, AIDS Or contact canbe indirect: Ex: through fomites such as clothes towels, pencils etc.

2.) Inhalation : (Air-borne) Inhalation can be a method of transmission eg. tuberculosis bacilli and influenza viruses.

3.) Ingestion : (Food-borne) Mode of infection by ingestion can be of three types: a) Water : e.g. Cholera b) Food :e.g. Staphylococcus food poisoning A Self-regulated Learning Module

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c)

Hand : e.g. bacillary dysentery

4.) Inoculation a) Introduction of organisms directly into the tissue e.g. b) tetanus spores inoculated in wounds c) rabies virus deposited subcutaneously by dog bite 5) Congenital Infection Pathogens are able to cross the placental barrier and infect the foetus in the uterus. This is known as vertical transmission. e.g. congenital syphilis, intrauterine infection.

Clinical Features of Infections: 1) Fever 2)

Chills

3)

Myalgia

4)

Photophobia

5)

Lymphadenopathy

6)

Splenomegaly

7)

G.I.Upset

Diagnosis of Infection A)

Direct evidence of infection i) Direct microscopic examination a) Gram stain b) Ziehl – Neelsen stain ii) Cultures

B) Indirect evidence of infection a) Blood b) Urine analysis Bacterial Resistance 1. Natural Resistance: 2. Acquired Resistance a) Mutation 3. Cross Resistance INFECTIONS: 1. UTI =Urinary Tract Infections A Self-regulated Learning Module

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2. Gynecological Infections 3. Sexually Transmitted Diseases 4. Lower Respiratory Tract Infection 5. Gastrointestinal Infections 6. Bone and Joint Infections 7. Skin and Soft Tissue Infections 8. Post Operative Infections Antibiotic Terminology •

Bacteriostatic : - A bacteriostatic antibiotic is one that is able to inhibit the growth or multiplication of bacteria.

•

Bactericidal : - A bactericidal antibiotic is one that is able to kill bacteria usually when they are in the process of multiplication.

• M.I.C. : - (Minimum Inhibitory Concentration) It is the smallest amount of antibiotic required to inhibit or suppress the growth of the bacteria.

• M.B.C. : - (Minimum Bactericidal Concentration) It is the smallest amount of antibiotic required to destroy or kill bacteria.

• Resistance : - Bacteria that are not susceptible to a particular antibiotic are said to be resistant to that antibiotic.

• Cross Resistance: - Bacteria that are resistant to one antibiotic and also demonstrate resistance to another different antibiotic are said to show cross resistance.

(This is normally present in antibiotics which a similar structure).

• Spectrum: - The range of bacteria against which an antibiotic is effective is called the antibacterial spectrum of that antibiotic Classification of Anti-microbial Agents A) Chemical Structure 1. ꞵ- Lactam Antibiotics : Penicillins, Cephalosporins, Monobactams, Carbapenems 2.

Tetracyclines : Oxytetracycline, Doxycycline etc.

3.

Aminoglycosides : Streptomycin, Gentamycin, Neomycin etc.

4.

Macrolide Antibiotics : Erythromycin,Oleandomycin, Roxithromycin 5.

Quinolones : Nalidixic acid, Norfloxacin, Ciprofloxacin, Pefloxacin 6.

Imidazole Derivatives : Miconazole, Ketoconazole, Clotrimazole, Fluconazole B) Mechanism of Action 1.

Inhibit Cell Wall Synthesis : Penicillins, Cephalosporins, Cycloserine, Vancomycin, Bacitracin.

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2.

3.

4.

Inhibit Protein Synthesis : Tetracyclines, Chloramphenicol, Erythromycin, Clindamycin Interfere With DNA Function : Rifampin, Norfloxacin, Metronidazole Causing Leakage from Cell Membranes : Amphotericin B, Nystatin

C) Spectrum of Activity 1. Antibacterial : Pencillins, Aminoglycosides, Erythromycin etc.

2. Antifungal : Griseofulvin, Amphotericin B, Ketoconazole etc.

3. Antiviral : Idoxuridine, Acyclovir, Amantadine, Zidovudine etc.

4. Antiprotozoal : Chloroquine, Pyrimethamine, Metronidazole, Diloxanide etc.

5. Anthelmintic : Mebendazole, Piperazine, Pyrantel pamoate etc.

D) Type of Action

Primarily Bacteriostatic

Primarily Bactericidal

Sulfonamides

Penicillins

Tetracyclins

orins Aminoglycosides

Cephalosp

Vancomyci Chloramphernicol

n Polypeptides acid

Erythromycin

Rifampin

Ethambutol

acin Cotrimoxazole

Nalidixic

Ciproflox

Idoniazi d E. Source

Fungi

Bacteria

Penicillin

Polymyxin B

Cephalosporin

Colistin

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Griseofulvin

Bacitracin

Tyrothricin

Aztreonam

Selection of an Anti-microbial Agent: • Clinical evaluation of the probable etiology • Identification of the causative micro-organism and antimicrobial drugs.

• Nature of the drug • Severity of the disease and general condition of the patient • Risk of toxicity of the drug • Age of the patient • Pregnancy and neonatal period • Possibility of drug resistance • History of previous allergic reactions • Cost of the therapy Tissue and Cell Penetration –Success of antimicrobial therapy depends on the concentration of antibiotics reaches the site of infections.

that

–Tissue Penetration is the amount of drug found in tissue cells and interstitial fluid.

Combination of Antibiotics • Normally, single antibiotics are used •

Combination therapy is necessary in patients with mixed or lifethreatening infections.

Why are Antibiotics Combined?

• To achieve an additive or synergistic effect against a single organism • In mixed infections with bacteria sensitive to different drugs • To delay the development of resistance • To decrease the adverse reactions of an individual drug so that the dose of a drug can be reduced • When the infection is severe and the body defence is poor Beta-lactam Antibiotics • The discovery of Penicillin by Alexander Fleming in his London Hospital Laboratory in 1928 was a milestone in the battle between human and microbes A Self-regulated Learning Module

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•

Penicillins, Cephalosporins – A boon to mankind

MECHANISM OF ACTION OF PENICILLINS ✔ Drug enters the bacterial cell ✔ Binds to Penicillin Binding Proteins ✔ No transpeptidase production ✔ No crosslinking of peptidoglycan chain ✔ Weak bacterial cell wall ✔ Lysis of the bacteria •

Penicillin G, Penicillin V

•

Penicillinase-resistant Penicillins – Methicillin, Cloxacillin

•

Aminopenicillins –Ampicillin, Amoxycillin

•

Antipseudomonal Penicillins – Ticarcillin

• Cephalosporins appear to inhibit bacterial cell wall synthesis in a manner similar to that of penicillins. Structurally they are closely related to penicillins and belong to the same class of b-lactam antibiotics First – Generation Cephalosporins - Cefzolin, Cephalexin, Cefadroxil These cephalosporins have good activity against gram-positive bacteria but poor activity against gram-negative bacteria.

Second – Generation-Cephalosporin • •

Cefuroxime, Cefoxitin, Cefaclor, The second generation cephalosporins have increased activity against gram-negative micro-organisms.

Third Generation Cephalosporins • Cefotaxime, Ceftazidime, Cefoperazone, Ceftizoxime, Ceftriaxone, Cefpodoxime • Cefixime-oral • These antibiotics generally have increased potency and a wider spectrum of activity against clinically important gram-negative bacteria. But they are less potent than the first generation agents against gram-positive bacteria.

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☞ Cefepime is considered a fourth generation cephalosporin due to it's intrinsic antimicrobial properties. Fourth generation cephalosporins are projected to have many attributes including: ☞ extended spectrum of activity for gram negative and gram positive organisms (different from third generation cephalosporins) ☞ minimal Beta-lactamase activity due to rapid periplasmic penetration and high penicillin-binding protein (PBP) access ☞ spectrum of activity to include gram negative organisms with multiple drug resistance patterns (Enterobacter and Klebsiella)

The basic mechanisms by micro-organisms may become resistant to beta-lactams includes: 1. Beta-lactamses 2. Permeability Resistance 3. Changes in Penicillin Binding Proteins (PBP) 4. Mixed Mechanism of Resistance Beta-lactamase Mediated Resistance • Beta-lactamases are enzymes that recognize and attack beta-lactam ring of the antibiotics • Penicillins are hydrolysed into bacteriologically inactive penicilloic acid • Intact antibiotic never reaches its target proteins in the bacterial cell wall • Ability to produce these enzymes is now widespread in bacteria Approaches to Overcome Beta-lactamase Resistance • Development of entirely new class of antibiotics. Eg: Quinolones • Development of new beta-lactam antibiotics resisting hydrolysis by betalactamase. Eg: New Cephalosporins • Development of Beta-lactamase inhibitors. Eg: Sulbactam and Clavulanic Acid Beta-lactamase Inhibitor • Sulbactam – Binds irreversibly to the beta-lactamase enzymes – Effective against Class A & C of beta-lactamases • Clavulanic Acid – Binds irreversibly to the beta-lactamase enzymes – Induces production of beta-lactamase in some organisms – Effective against Class A of beta-lactamases MACROLIDES: includes – Azithromycin – Clarithromycin – Dirithromycin A Self-regulated Learning Module

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– Erythromycin – Roxithromycin QUINOLONES: includes – Nalidixic Acid – Norfloxacin – Ciprofloxacin – Sparfloxacin – Lomefloxacin – Ofloxacin – Gatifloxacin – Moxifloxacin 3 Ds of Appropriate Antibiotic Use ⮚ The Right Drug. Use only the antibiotic that your healthcare professional prescribed for your condition, and not one used by another person or for another illness. ⮚ The Right Dose. Take the prescribed amount of your drug at the correct times. ⮚ The Right Duration. Even if you start to feel better, continue taking your drug for the full course (the prescribed number of days) to ensure that no bacteria can survive.

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Quiz Time 1. What were the first compounds used to combat infection?

A. Silicon and magnesium B. Mercury and Arsenic C. Ferrous and aluminum Oxide D. Magnesium and Arsenic 2. Are Quinolones natural or Synthetic?

A. Synthetic B. Natural C. Both A & B D. Nonr of the above 3. Why are sulfonamides given in conjunction with trimethoprim?

A. This drug blocks the protein sythesis by dihydrofolate.

B. This drugs needs another drug to activate the effect of the chemical compound in them.

C. This drug inhibits folic acid synthesis by acting on dihydrofolate reductase. This 2 hit attack on the same pathway is often much more successful than either drug alone.

D. This drugs are a class of medication used for treating viral infections’ targeting specific viruses.

4. A low percentage of humans develop a severe, fatal, aplastic anemia if treated with this drug which is also strictly prohibited in food animal use.

A. trimethoprin B. Rifmpicin C. Nitrofurans D. Chloramphenicol 5. Ceftoxin is a second generation of cephalosporin.

A. True B. False C. None 6. Fluconazole can be used systematically.

A. True B. False C. None 7. Amphoteracin B is used to treat systemic fungal infections but has a number of serious side effects such as nephrotoxicity.

A. True B. False C. None 8. How can a bacteria acquire antimicrobial resistance?

A. is spread when blood, semen, or other body fluid infected with the A Self-regulated Learning Module

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hepatitis B virus enters the body of someone who is not infected.

B. when someone near you coughs or sneezes. Or, if you touch something the virus is on, like Ellen and Jack's phone or doorknob, and then touch your nose or mouth, you could catch the flu.

C. transfer of plasmids, transposons, and integrons, infection with a bacteriophage, mutation.

D. In some cases, multiple mutations are required for the development of high level resistance, and insufficient suppression of viral replication by antiviral drugs will predispose to their sequential acquisition.

9. How do Sulfonamides work?

A. It helps to maintain normal nerve and muscle function, supports a healthy immune system, keeps the heartbeat steady, and helps bones remain strong.

B. is an essential element for blood production.

C. is a charged particle (ion) that contains the mineral phosphorus.

D. They complete with PABA this inhibits the growth of the bacteria.

10. What is unique about the shape of Penicillin?

A. Their lactam ring looks like the substrate that the transpeptidase of the bacteria will bind to. When it mistakenly binds the penicillin it is inactivated.

B. can efficiently transfer heat and electricity and this ability is surpassed only by silver and copper.

C. up 2 percent of the Earth's crust, but you won't see this silvery, light metal in nature.

D. Only the white allotrope or form of phosphorus glows in the dark.

11. How does penicillin Kill bacteria?

A. They interfere with an important enzyme of the influenza virus, called Neuraminidase.

B. Anthracyclines kill cancer cells by damaging their genes and interfering with their reproduction.

C. They kill actively growing cells by weakening the peptodoglycan until the bacteria bursts.

D. triphosphate inhibits viral DNA polymerase by competing with deoxyguanosine triphosphate for incorporation into the growing DNA strand.

12. Cell-wall biosynthesis is inhibited by antibiotics by inhibiting the biosynthesis of which of the following?

A. cellulose B. proteins C. peptidoglycan D. lipopolysaccharide 13. Which of the following does not affect the activity of penicillin?

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D. Hydochloric acid 14. Which of the following interferes with the regeneration of the monophosphate form of bactoprenol from the pyrophosphate form?

A. Bacitacin B. Vancomycin C Cephalosporin D. Ampicillin 15. Benzylpenicillin is the chemical name for which of the following penicillin?

A) Penicillin G B) Penicillin V C) Penicillin F D) Phenethicilin

ANTIVIRAL AGENTS ●

Antiviral drugs are virustatic - Only effective against actively replicating viruses, they cannot kill the latent viruses present in the body.

We draw a host cell and remind ourselves of the following steps of the virus life cycle: ☞ Adhesion ☞ Entry ☞ Uncoating ☞ Synthesis and Assembly ☞ Virion release Anti-viral agents interrupt these stages as follows: ▪ Disrupt the viral envelope or surface proteins, preventing viral transmission.

▪ Block penetration and uncoating, which prevents the viral nucleic acids from reaching their replication sites.

▪ Inhibit RNA or DNA synthesis ▪ Block the assembly and release or virions, which prevents their spread.

Details and Examples: Lipids, detergents, acids and other anti-viral molecules can disrupt the surfaces of some viruses.

For Example: - Citric acids disrupt the surface proteins of rhinoviruses.

- Thus some believe that adding citric acids facial tissues might help prevent rhinovirus transmission.

Examples of agents that prevent viral attachment to the host cell: ● Antibodies can neutralize viral attachment proteins on most viruses. ● Peptide Analogue can block host attachment proteins.

- Drugs that block the HIV co-receptor necessary for entry.

• Peptides can bind heparan sulfate (and other similar sites) on ost cells, blocking the attachment of HIV and Herpes Simplex Viruses.

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Examples of Agents that prevent penetration and uncoating of virions: • Inhibition of viral fusion proteins - Enfuvirtide blocks HIV fusion.

•

Inhibition of envelope fusion - Docosanol blocks envelope fusion of HSV and other viruses

•

Neutralize vesicle pH - which inhibits viral uncoating - Amantadine and rimantadine use this mechanism against Influenza A.

●

Prevent Penetration - Tromantadine is a drug that prevents HSV penetration ● Block receptors to prevent uncoating - Arilidone, dioxaril, and pleconaril prevent picornaviruses.

Examples of agents inhibit RNA or DNA synthesis and block viral replication Nucleotide and nucleoside analogues, as well as non-nucleoside polymerase inhibitors ●

Nucleoside Analogues - Acyclovir is active aginst Herpes viruses and Varicella-Zoster Virus (VZV); Valayclovir is a prodrug of acyclovir - Penciclovir is used to treat Herpes simplex viruses (specifically, cold sores), Varicella -Zoster virus, Epstein-Barr infections, and Cytomeglovirus (CMV) infections; Famciclovir is a prodrug of penciclovir - Azidothymidine (aka, AZT), Dideoxyinosine, Stavudine, and Lamivudine are used to treat HIV infections - Cidofovir is used to treat Cytomegalovirus infections, especially in patients with AIDS, as well as Polyomavirus, Papillomavirus, and Herpes Simplex Virus infections.

- Adefovir is used to treat Hepatitis B (HBV) infections

●

Non-nucleoside polymerase inhibitors - Foscarnet is used to treat infections caused by Herpes Virus, HIV and Cytomegalovirus retinitis in AIDS patients.

- Nevirapine, Delvaridine and Efavirenze are used to treat Herpes virus and HIV

Examples of protease and neuraminidase inhibitors that block virion assembly and release: ●

.Protease Inhibitors: Saquinavir, ritonavir and indinavir, which are acive aginst HIV

●

Neuraminidase Inhibitors: Zanamivir and oseltamivir which are A Self-regulated Learning Module

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active agianst Influenza A and B

ANTIVIRAL AGENTS 1.

2.

3.

4.

Anti-herpes agents Ani HIV agents Drugs used for hepatitis B& C Anti influenza agents

1.) ANTI-HERPES AGENTS Drugs: Acyclovir, Famciclovir Mechanism of Action: > Inhibits herpes virus DNA Polymerase. > Gets incorporates in viral DNA and stops lenthening of DNA strands.

Adverse Effects: > nausea, diarrhea may occur > renal toxicity > neurologic effects 2.) ANTI HIV AGENTS (anti-retroviral agents) Classes of Anti-retroviral drugs nowasdays A. NRTI (nucleoside/nucleotide Reverse transcriptase inhibitors) B. NNRTI (non-nucleoside Reverse transcriptase inhibitors) C. PI (Protease Inhibitors) D. FI (Fusion Inhibitors) E. HIV integrase inhibitors A.) NRTI (nucleoside/nucleotide reverse transcriptase inhibitors) DRUGS: Tenofovir, Didanosine (ddl) Mechanism of Action: > NRTIs act by competitive inhibition of HIV-1 reverse transcriptaseIncorporation into growing viral DNA chain causes premature chain termination due to inhibition of binding with the incoming nucleotide. > Adverse Effects: Neurotoxic, neuropathy pancreatitis B,) NNRTI (non-nucleoside reverse trancriptase inhibitors) DRUGS: Delavirdine, Etravirine Mechanism of Action: > Bind directly to HIV-1 reverse transcriptase, resulting in inhibition of RNA and DNA dependent polymerase activity. > It do not require phosphorylation to be active.

Adverse Effects: Skin rash, GI intolerance

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C.) PI Protease Inhibitors DRUGS: Indinavir, Ritonavir Mechanism of Action: > Pls prevent the processing of viral proteins into functional conformations, resulting immature, noninfectious viral particles.

Adverse Effects: Redistribution of accumulation of body fat D.) FI (Fusion Inhibitors) DRUGS: Enfuvirtide Mechanism of Action: > Fusion inhibitor that blocks HIV entry into the cell, binds to subunit of the viral envelope glycoprotein.

Averse Effect: > local injection site reactions.

E.) HIV Integrase Inhibitors DRUGS: Dolutegravir Mechanism of Action: > Integrase strand transfer inhibitors prevent integration of the viral DNA into the host DNA by inhibiting the viral enzyme integrase > Bind inhibiting the viral enzyme essentail to the replication of HIV. 3.) DRUGS used for HEPATITIS B&C ⮚ The goals chronic HBV therapy ● To sustain suppression of HBV replication, resulting in slowing of progression of hepatic disease. ● To prevent complications (ie; cirrhosis, hepatic failure) and ● To reduce the need for liver transplantation.

INTEFERONS > are host cytokines that exert complex antiviral, immunomodulatory actions. > Interferons appear to functions by Induce intracellular signals for resulting inhibition of viral penetration, translation, transcription, protein processing, maturation and release.

Inteferon Inducers: > Agents that promote the production and release of interferons.

Adverse Effects: > Neurotoxicities 4.) ANTI-INFLUENZA AGENTS DRUGS: Zanamivir & Rimantidine Mechanism of Action: > Interfere with release of progeny influenza virus from infected host cells. > Inhibit the uncoating of viral RNA within infected host cells plus preventing its replication.

Adverse Effects: > Pneumonia, Asthma

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QUICK QUIZ 1. Why do we make a prodrug form?

A. to increase oral bioavailability B. to avoid rapid onset of the drug C. to prolong the effect D. to avoid the destruction of its components.

2. Acyclovir is used for herpes labialis.

A. True B. False C. No 3. Why are viruses hard to treat?

A. they have a sticky crown B. they are based on fats and can penetrate to our vascular organ.

C. they rely on humans to replicate D. they are very corrosive.

4. What is foscarnet used for?

A. PTB B. CMV in AIDS and HSV infections C. Chikungunya virus infection B. chickenpox/shingles 5.zidovudine(Retrovir) Major dose-limiting adverse effect is A. immune system B. raltegravir (Isentress) C. Influenza types A and B reduces duration of illness D. Bone marrow suppression 6. Antiviral Drugs (non-HIV): Ribavirin Inhalation form _________ used for hospitalized infants with Respiratory syncytial virus (RSV) infections A. Reverse transcriptase B. HIV C. Virazole D. Respiratory syncytial virus (RSV) 7. Opportunistic Infection: Kaposi's sarcoma, others A. Viral B. bacterial C. raltegravir D. Opportunistic neoplasias 8. Opportunistic Infection: A Self-regulated Learning Module

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Major weight loss, chronic diarrhea, chronic fever A. Bacterial B. Viral C. HIV wasting syndrome D. Opportunistic neoplasias 9. Herpes-simplex viruses → Used to treat infections caused by HIV, the virus that causes AIDS A. True B. False 10. acyclovir (Zovirax) used to suppress replication of: → HSV-1 (oral herpes) HSV-2 (genital herpes); Varicella zoster virus (VZV) A. True B. False

Fill-up the needed information Drug Classification

list 3 Generic Name each

List down 3 diseases treated by antiviral agents

Influenza A and Respiratory Viruses Drugs Show how the drug classification above work to treat the disease:

Herpes and Cytomegaloviruses (CMV) Show how the drug classification above work to treat the disease:

Non-nucleoside Reverse Transcriptase Inhibitors Show how the drug classification above work to treat the disease:

Nucleoside Reverse Transcriptase Inhibitors (NRTI) Show how the drug classification above work to treat the disease:

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Protease Inhibitors Show how the drug classification above work to treat the disease:

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ACTIVITY 7 MICROSCOPIC EXAMINATION OF BACTERIA I.

OBJECTIVE The students are expected to discuss the characteristics of bacteria.

II.

DISCUSSION Danish Physician Hans Christian Gram (1853-1938) developed the Gram stain. When freshly grown bacterial cells are treated with the reagents used in the Gram stain, they can be categorized into one of two classes: Gram (+) or Gram (-). Gram (+) class will appear blue or violets while the Gram (-) class will appear red or pink.

The physiology and structure of a microorganism is intimately associated with its ability to produce disease.

The cell wall is a tough and rigid structure surrounding the cell. The rigid part is the peptidoglycan. Peptidoglycans are the structural elements of almost all bacterial cell walls. They constitute almost 95% of the cell wall in some Gram positive bacteria and as little as 5-10% of the cell wall in Gram negative bacteriaThe cell walls of gram positive bacteria have simpler chemical nature than those of gram negative bacteria.

The bacterial cytoplasmic membrane is composed of a PHOSPHOLIPID LAYER and thus has all of the general functions of a cell membrane such as acting as a permeability barrier for most molecules and serving as the location for the transport of molecules into the cell.

The cytoplasm is the TOTAL OF EVERYTHING INSIDE of the cytoplasmic membrane.

It contains the Cytosol or the Amorphous Matrix to which nearly all other functions not conducted by the cell membrane occur and it is where interior structures are suspended. It contains ribosomes, storage granules, nucleoid, plasmids, and transposons. Other parts may include a capsule, flagella, fimbriae, glycocalyx, and spores.

III.

MATERIALS Pencil, PPEs (lab gown), Reference materials IV.

Questions for research

1. What is acid fast staining?

- Is a differential stain used to identify acid-fast organisms such as members of the genus Mycobacterium. Acid-fast organisms are characterized by wax-like, nearly impermeable cell walls; they contain mycolic acid and large amounts of fatty acids, waxes, and complex lipids(www.austincc.edu)

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ZIEHL NEELSEN

KINYOUN

Common name Heating Primary stain Decolorizer Counterstain

3. Complete the tables A. Eukaryotic cell functions.

Parts of the cell

Function/s

Nuclear envelope Chromatin Nucleolus Peroxisome Endoplasmic reticulum Smooth E.R. Microtubules Centrosome Intermediate filaments Microfilaments Plasma membrane Lysosomes Golgi apparatus Cytoplasm Mitochondria A. Prokaryotic Cell

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Function/s

Parts of the cell Plasmid Cell membrane Cell wall Capsule Pili Flagella 4. Complete the following: A. Types of flagellum Flagellum

Description

Example (name of bacteria)

Monotrichous Lophotrichous Amphitrichous Peritrichous

5. Draw the following Coccus

Staphylococci

Diplococcus

Streptococci

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Tetrad

Coccobacillus

Bacillus

Diplobacillus

Palisades

Streptobacilli

Vibrios

Spirillum

Spirochetes

Pleomorphic

Monotrichous

Lophotrichous

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Peritrichous

Amphitrichous

6. Give example of diseases and name of causative agent according to the following : A. Diplococus –

B. Streptococcus – C. Staphyloccous

D. Bacillus – E. Vibrio –

F. Spirillum-

G. Spirochetes-

H. Gram positive bacteria-

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I. Gram negative bacteria-

J. Spore-forming bacteria -

7. What are the 10 most dangerous antibiotic-resistant bacteria? Illness caused? Antibiotic resistance? Virulence?

Name

Year First document ed

Illness caused

Antibiotic resistance (low, medium, high)

Virulence (deadly, worrying, dangerous)

Streptoco ccus pyogenes Neisser ia gonorr heae Mycobact erium tuberculos is Acinetob acter baumann ii Escherichia coli Klebsiell a pneumo niae Clostridium difficile Pseudom onas aeruginos A Self-regulated Learning Module

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a

Burkholderia cepacia Staphylococc us aureus (MRSAmethicillinresistant Staphylococc usaureus) By: Longitude team. August 26, 2014. Longitude prize. http://longitudeprize.org/blog-post/10-mostdangerous-antibiotic-resistant-bacteria

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ACTIVITY 8 MYCOLOGY I.

OBJECTIVE The students are expected to correctly define the different common terminologies related to fungi, describe the modes of transmission, and the common mycoses, the methods of controlling and preventing them.

II.

DISCUSSION Mycology is the study of the eukaryotic fungi. A typical fungus consists of the hyphae, spore and the septum. They are classified according to temperature requirement: the yeasts that grow at 37°C, the molds that grow at 22°C, and the dimorphism that has the ability to grow at either temperature.

Most fungi are beneficial to mankind. Humans are relatively resistant. Of the 100,000 fungal species, only 300 have been linked to disease in animals. They are the common plant pathogens.

Human mycoses are caused by true fungal pathogens and opportunistic pathogens. Pathogenic fungi cause different mycoses, ranging from superficial layers of the skin infections (e.g. Tinea infections) up to deep body tissues infections (Sporothrix schenkii infection).

Control of Mycotic Infections includes intravenous amphotericin B, flucytosine, azoles and nystatin; in some cases surgical removal of damaged tissues. Immunization is NOT usually effective.

Prevention is limited to makss and protective clothing to reduce contact with spores

III.

MATERIALS Pencil, PPEs (lab gown), Reference materials

IV.

Questions for research

1.

Fill up the table regarding the common fungal infections

Mycoses

Causative agent

Classification (Cutaneous/Subcutaneous/ systemic/opportunistic)

Tinea versicolor Tinea nigra Black piedra White piedra Tinea capitis A Self-regulated Learning Module

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Mycoses

Causative agent

Classification (Cutaneous/Subcutaneous/ systemic/opportunistic)

Tinea pedis Tinea manus Tinea corporis Histoplasmosis (Ohio Valley fever) Reticuloendothelial cytomycosis Blastomyces (North AmericanBlastomycosis) Chicago disease Gilchrist’s disease Paracoccidioidomycosis Posada’s disease San Joaquin valley fever Sporotrichosis (rosegardener’s disease) Cryptococcosis Candidiasis Chromoblastomycosis Mycetoma Pneumonia (PCP)

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2.

What are imperfect fungi?

- .

3.

Complete the portal of entry of the following mycoses

Mycoses

Portals of entry

Primary Subcutaneous Cutaneous Superficial 4.

What are the 5 virulence factors of the pathogenesis of the fungi?

5.

How can Mycotic infections be diagnosed?

Give three ways. a.

b.

c.

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UNIT VII Best and the worst: Important Issues in Microbiology

BIOTECHNOLOGY

Objectives: 1. Students will demonstrate, both verbally and in writing, knowledge of scientific theory related to biotechnology techniques.

2. Students will use technology to isolate, amplify, and detect DNA and proteins.

3. Students will consider, discuss and debate current ethical and legal issues in biotechnology.

4. Students will be able to demonstrate their understanding of and to utilize proper laboratory procedures within a regulated environment.

5. Students will be able to understand the relationship of biotechnology and medical environment.

Precede 1. What do we know about Biotechnology?

2. How biotechnology affects the advancement of the medical field?

Biotechnology = Any technological application that uses biological systems living organisms, or derivatives thereof to make or modify products or processes for specific use. = It is the manipulation of living organisms or parts of living organisms to make products useful to humans. = It deals with the manipulation of the genes of organisms to alter their behavior, characteristics, or value Microbial Technology: ▪ Production of therapeutic proteins. > Human genes are introduced (usually by transformation) into bacteria and yeasts. Such genetically engineered microorganisms have been used to produce therapeutic proteins such as human insulin, human growth hormone, human tissue plasminogen activator, interferon, and hepatitis B vaccine.

▪

Production of DNA vaccines > DNA vaccines (also called gene vaccines) are presently only experimental.

To prepare a DNA vaccine, a particular pathogen gene (let us use as an example the gene that codes for a specific protein on a pathogen’s surface) is inserted into a plasmid (E. coli plasmids have been used). Copies of the plasmid are then injected (usually intramuscularly) into a person’s tissue.

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After cells within that tissue internalize the plasmids, the cells produce copies of the gene product (the pathogen’s surface protein in this example). The person’s immune system then produces antibodies against that gene product, and the antibodies protect the person from infection with that pathogen.

▪

Production of vitamins > Bacteria can be used as sources of vitamins B2 (riboflavin), B7 (biotin), B9 (folicacid), B12, and K2.

▪

Use of microbial metabolites as antimicrobial agents and other types of therapeutic agents. > Penicillin and cephalosporins are examples of antibiotics produced by fungi.

Bacitracin, chloramphenicol, erythromycin, polymyxin B, streptomycin, tetracycline, and vancomycin are examples of antibiotics produced by bacteria.

▪

Agricultural applications > Certain microbial metabolites have microbicidal, herbicidal, insecticidal, or nematicidal activities.

For example, a soil bacterium named Bacillus subtilis secretes compounds with antifungal, antibacterial, and insecticidal activities.

▪ Food technology > Microorganisms are used in the production of foods such as acidophilus milk, bread, butter, cocoa, coffee, cottage cheese, cultured buttermilk, fish sauces, green olives, kimchi (from cabbage), meat products (e.g., country-cured hams, sausage, salami), olives, pickles, poi (fermented taro root), sauerkraut, sour cream, soy sauce, tofu, various ripened cheeses (e.g., Brie, Camembert, Cheddar, Colby, Edam, Gouda, Gruyere, Limburger, Muenster, Parmesan, Romano, Roquefort, Swiss), vinegar, and yogurt. > Yeasts are used in the production of alcoholic beverages, such as ale, beer, bourbon, brandy, cognac, rum, rye whiskey, sake (rice wine), Scotch whiskey, vodka, and wine. > Microbes are used in the commercial production of amino acids (e.g., alanine, aspartate, cysteine, glutamate, glycine, histidine, lysine, methionine, phenylalanine, tryptophan) for use in the food industry. > Algae and fungi are used as a source of single-cell protein for animal and human consumption.

▪

Production of chemicals > Microbes can be used in the large-scale production of acetic acid, acetone, butanol, citric acid, ethanol, formic acid, glycerol, isopropanol, and lactic acid, as well as biofuels such as hydrogen and methane.

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▪

Biomining > Microbes have been used in the mining of arsenic, cadmium, cobalt, copper, nickel, uranium, zinc, and other metals by a process known as leaching or bioleaching.

▪

Bioremediation > The term bioremediation refers to the use of microorganisms to clean up various types of wastes, including industrial wastes and other pollutants (e.g., herbicides and pesticides). Some of the microbes used in this manner have been genetically engineered to digest specific wastes.

For example: genetically engineered, petroleum-digesting bacteria were used to clean up the 11 million–gallon oil spill in Prince William Sound, Alaska, in 1989. At a government defense plant in Savannah River, Georgia, scientists have used naturally occurring bacteria known as methanotrophs to remove highly toxic solvents such as trichloroethylene and tetrachloroethylene (collectively referred to as TCEs) from the soil. The methanotrophs, which normally consume methane in the environment, were more or less “tricked” into decomposing the TCEs. IN addition, microbes are used extensively in composing, sewage treatment, and water purification.

▪

Other > Microbial enzymes used in industry include amylases, cellulase, collagenase, lactase, lipase, pectinase, and proteases. > Two amino acids produced by microbes are used in the artificial sweetener called aspartame (NutraSweet).

PROS and CONS Prose: 1. It can improve health and reduce hunger simultaneously.

2. It creates flexibility within the food chain 3. It offers medical advancement opportunities 4. It allows us to preserve resources 5. It helps us minimize waste products 6. It can reduce infectious disease rates.

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1. It creates an all or nothing approach 2. It is field of research with many unknowns 3. It can be used for destruction 4. It could ruin croplands

BIOTERRORISM AND BIOLOGICAL WARFARE

Objectives: Upon completion of this course, you should be able to: 1. Discuss the role of the medical professional in the event of a bioterrorism attack.

2. Compare available bacterial agents, their diagnosis, and treatment procedures, and how they could be used during a bioterrorist attack.

3. Analyze viral agents with the potential for bioterrorist use, including smallpox and viral hemorrhagic fevers.

4. Apply a disaster plan for acts of terrorism that involve biologic weapons, including considerations for non-English-proficient populations.

5. Evaluate biological toxins and how they might be used in biowarfare.

BIOTERRORISM > the unlawful use, or threatened use, of microorganisms or toxins derived from living organisms to produce death or disease in humans, animals, or plants. The act is intended to create fear and intimidate governments or societies in the pursuit of political, religious, or ideological goals.

BIOLOGICAL WARFARE AGENTS > (also known as germ warfare) is the use of biological toxins or infectious agents such as bacteria, viruses, and fungi with intent to kill or incapacitate humans, animals or plants as an act of war by a state or nation.

BIOLOGICAL AGENTS > (“bio-weapons”) are living organisms or replicating entities (viruses) that reproduce or replicate within their host to cause harm. > They are microorganisms such as viruses, bacteria or fungi that infect humans, livestock or crops and cause an incapacitating or fatal disease. Symptoms of illness do not appear immediately but only after a delay, or ‘incubation period’, that ay last for days or weeks.

▪

BIOLOGICAL WARFARE ATTACK: ☞ Intent is to conquer through incapacitation or lethality ☞ Little concern about deniability ☞ Likely to involve a delivery device ☞ Dose-response optimized ☞ Self-protection is considered

▪

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☞ ☞ ☞ ☞

Attention to a cause Fear and disruption Economic impact Social and political pressures to change our will and society

AGENTS of BIOLOGICAL WARFARE Key Features of Biologic Agents Used as Bioweapons 1. High morbidity and mortality 2. Potential for person-to-person spread 3. Low infective dose and highly infectious by aerosol 4. Lack of rapid diagnostic capability 5. Lack of universally available effective vaccine 6. Potential to cause anxiety 7. Availability of pathogen and feasibility of production 8. Environmental stability 9. Database of prior research and development 10. Potential to be “weaponized” CDC Category A, B and C Agents ▪ Category A: High priority agents - easily disseminated or transmitted from person to person - high mortality rates - potential for major public health impact - might cause public panic and social disruption - require special action for public health preparedness ▪

Category B: 2nd highest priority - moderately easy to disseminate - moderate morbidity rates and low mortality rates - require specifically enhanced diagnostic capacity

▪

Category C: emerging pathogens - general population lacks immunity - could be engineered for mass dissemination in the future because of Availability - ease of production, ease of dissemination - potential for high morbidity and mortality and - major public health impact

CATEGORY A CATEGORY B Anthrax (Bacillus anthracis) Psittacosis (Ch. Psittaci) Botulism (CI. Botulinum Epsilon toxin of Cl. Perfringens toxin) Plague (Yersinia pestis) Smallpox (Variola major) Turalemia (Francisella tularensis)

CATEGORY C (Emerging infections) Hantavirus

Melioidosis (B. pseudomallei) SARS coronavirus Glanders (Bukholderia mallei) Pandemic influenza Food safety threats (e.g. Nipah Salmonella spp., E.coli, Shigella A Self-regulated Learning Module

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Viral hemorrhagic fevers: Viral encephalitis [alphaviruses Lassa, New world (Machupo, (e.g., Venezuelan, eastern, and Junin, Guanarito, Sabia) western equine encephalitis)] Crimean Congo, Rift Valley, Edola, marburg Brucellosis (Brucella spp.)

Q fever (Coxiella burnetii) Ricin toxin from Ricinus communis (castor beans) Staphylococcal enterotoxin B Water safety threats (e.g., V. cholerae, Cr. parvum) Typhus fever (R. prowazekii Anthrax (Bacillus anthracis) ⮚ Anthrax infections involve marked hemorrhaging and serous effusions (fluid that has escaped from blood or lymphatic vessels) in various organs and body cavities and are frequently fatal. Of the three forms of anthrax, inhalation anthrax is the most severe, followed by gastrointestinal anthrax and then cutaneous anthrax. ⮚ Bioterrorist could disseminate B. anthracis spores via aerosols or contamination of food supplies. In the fall of 2001, letters containing B. anthracis spores were mailed to several politicians and members of the news media. According to the CDC, a total of 22 cases of anthrax resulted: 11 cases of inhalation anthrax (with 5 fatalities) and 11 cases of cutaneous anthrax (with no fatalities). Undoubtedly, many additional cases were prevented as a result of prompt prophylactic (preventative) antibiotic therapy.

▪ Infection – By cutaneous and inhalational route ▪ Signs/Symptoms Cutaneous Pulmonary 95% cases 5% cases 1-5 days 1-6 days (60 days) Fever, tiredness, headache Fever, Headache, Cough Pustules, eschar Dyspnea, Chest pain ▪

Diagnosis: - Skin biopsy for cutaneous - Blood culture - ELISA, PCR

MODE

of ANTHRAX SUBMISSION

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▪

Treatment: - Ciprofloxacin, penicillin, Doxycycline.

- Treated for 60 days.

▪

Prevention: - Vaccination – 6 doses over 18 months, booster annually.

- Chemoprophylaxis – Cipro/Doxy 4 weeks before exposure.

▪

Infectious form: Spores - Hardy, resistant to environmental conditions.

- Relatively easy to weaponize.

BOTULISM ☞ is a potentially fatal microbial intoxication, caused by botulinal toxin, a neurotoxin produced by C. botulinum. C. botulinum is a spore-forming, anaerobic, Gram-positive bacillus.

Botulinal toxin may cause nerve damage, visual difficulty, respiratory failure, flaccid paralysis of voluntary muscles, brain damage, coma, and death within a week if untreated. Respiratory failure is the usual cause of death. Bioterrorists could add botulinal toxin to water supplies or food. Botulinal toxin is odorless and tasteless, and only a tiny quantity of the toxin need be ingested to cause a potentially fatal case of botulism. Botulism can also result from entry of C. botulinum spores into open wounds.

SMALLPOX

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☞ is a serious, contagious, and sometimes fatal viral disease. Patients experience fever, malaise, headache, prostration, severe backache, a characteristic skin rash and occasional abdominal pain and vomiting. Smallpox can become severe, with bleeding into the skin and mucous membranes, followed by death. The last case of smallpox in the United States was in 1949, and the last naturally occurring case in the world was in Somalia in 1977. Since 1980, when the WHO announced that smallpox had been eradicated, most people no longer received smallpox vaccinations. Thus, throughout the world, huge numbers of people are highly susceptible to the virus.

PLAGUE ☞ is caused by Y. pestis, a Gram-negative coccobacillus. Plague is predominantly a zoonosis and is usually transmitted to humans by flea bite. Plague can manifest itself in several ways: bubonic plague, septicemic plague, pneumonic plague, and plague meningitis. ☞ Bubonic plague is named for the swollen, inflamed, and tender lymph nodes (buboes) that develop. ☞ Pneumonic plague, which is highly communicable, involves the lungs. It can result in localized outbreaks or devastating epidemics. ☞ Septicemic plague may cause septic shock, meningitis, or death. Patients with plague are depicted ☞ Bioterrorists could disseminate Y. pestis via aerosols, resulting in numerous severe and potentially fatal pulmonary infections. Pneumonic plague can be transmitted from person to person.

Water Supplies and Sewage Disposal Water is the most essential resource necessary for the survival of humanity. The main sources of community water supplies are surface water from rivers, natural lakes, and reservoirs, as well as groundwater from wells.

Chemical pollution of water occurs when industrial installations dump waste products into local waters without proper pretreatment, when pesticides are used indiscriminately, and when chemicals are expelled in the air and carried to earth by rain (“acid rain”).

Waterborne epidemics today are the result of failure to make use of available existing knowledge and technology. In those countries that have established safe sanitary procedures for water purification and sewage disposal, outbreaks of typhoid fever, cholera, and dysentery occur only rarely.

Sources of Water Contamination: • Rainwater falling over large areas collects in lakes and rivers and, thus, is subject to contamination by soil microbes and raw fecal material.

•

The city downstream must then find some way to rid its water supply of the pathogens.

In many communities, untreated raw sewage and industrial wastes are dumped directly into local waters. Also, a storm or a flood may result in contamination of the local drinking water with sewage.

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•

Groundwater from wells also can become contaminated. To prevent such contamination, the well must be dug deep enough to ensure that the surface water is filtered through soil before it reaches the level of the well.

Water Treatment • Water must be properly treated to make it safe for human consumption. It is interesting to trace many steps involved in such treatment. The water first is filtered to remove large pieces of debris such as twigs and leaves.

•

Next, the water remains in a holding tank, where additional debris settles to the bottom of the tank; this phase of the process is known as sedimentation or settling.

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Alum (aluminum potassium sulfate) is then added to coagulate smaller pieces of debris, which then settle to the bottom; this phase is known as coagulation or flocculation.

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The water is then filtered through sand or diatomaceous earth filters to remove the remaining bacteria, protozoan cysts and oocysts, and other small particles.

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Finally, chlorine gas or sodium hypochlorite is added to a final concentration of 0.2 to 1.0 ppm; this kills most remaining bacteria. In some water treatment facilities, ozone (O3) treatment or ultraviolet light may be used in place of chlorination.

Steps in Water Treatment

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Sewage Treatment • Raw sewage consists mainly of water, fecal material (including intestinal pathogens), and garbage and bacteria from the drains of houses and other buildings. When sewage is adequately treated in a disposal plant, the water it contains can be returned to lakes and rivers to be recycled.

A. Primary Sewage Treatment In the sewage disposal plant, large debris is first filtered out (called screening), skimmers remove floating grease and oil, and floating debris is shredded or ground. Then, solid material settles out in a primary sedimentation tank. Flocculating substances can be added to cause other solids to settle out. The material that accumulates at the bottom of the tank is called primary sludge.

B. Secondary Sewage Treatment The liquid (called primary effluent) then undergoes secondary treatment, which includes aeration or trickling filtration. The purpose of aeration is to encourage the growth of aerobic microbes, which oxidize the dissolved organic matter to CO2 and H2O. Trickling filters accomplish the same thing (i.e., conversion of dissolved organic matter to CO2 and H2O by microbes), but in a different manner. After either aeration or trickling filtration, the activated sludge is transferred to a settling tank, where any remaining solid material settles out. The remaining liquid (called secondary effluent) is filtered and disinfected (usually by chlorination), so that the effluent water can be returned to rivers or oceans.

C. Tertiary Sewage Treatment In some desert cities, where water is in short supply, the effluent water from the sewage disposal plant is further treated (referred to as tertiary sewage treatment), so that it can be returned directly to the drinking water system; this is a very expensive process. Tertiary sewage treatment involves the addition of chemicals, filtration (using fine sand or charcoal), chlorination, and sometimes distillation.

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Unit 7 Check for Facts and Understanding Multiple choices: Choose the correct answer.

1. Which of the following are considered reservoirs of infection?

A. carriers B. contaminated food and drinking water C. rabid animals D. all of the above 2. All of the following are major steps in the treatment of a community’s drinking Water except: A. boiling B. filtration C. flocculation D. sedimentation 3. The black death outbreak of plague in 14th century is regarded as the greatest public health disaster in recorded history?

A. True B. False C. No D. Maybe 4. Terrorism by intentional release or dissemination of biological agents A. What are the two types of bioterrorism events?

B. What is the Geneva protocol?

C. Define bioterrorism D. What are the routes of delivery of bioterrorism?

5. The protocol for the prohibition of the use in war of asphyxiating, poisonous or toher gases, and of bacteriological methods of warfare A. What are the two types of bioterrorism events?

B. What is the Geneva protocol?

C. Define bioterrorism D. What are the routes of delivery of bioterrorism?

6. Category A A. cause botulism B. 3 categories of bioterrorism agents C. step to take if a bioterrorism is suspected D. this category includes organism or toxins that pose the highest risk to public health and national security 7. Category C A. What category does Q fever belong to?

B. third highest priority, includes emerging pathogens C. a primitive biological weapon delivery device D. main bacteria species that classified in Cat C 8. Pneumonia A. clinical effects of Q-fever B. clinical effects of anthrax C. clinical effects Tularemia A Self-regulated Learning Module

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D. clinical effect of water poisoning 9. Incubation: 10-14 days, Fever to rash to pustules to scabs A. smallpox signs and symptoms B. Gastrointestinal anthrax C. treatment goals nerve agents D. Treatment of tularemia 10. Bioterrorism A. Mechanism of toxicity vesicant agents and chemical agents.

B. Deliberate release of virus, bacteria or another agent that induce death or illness C. Mechanism of toxicity, pulmonary agents.

D. A liquidation of chemicals that are being spared during farming then mix to the environment .

11. In the sewage disposal plant, large debris is first filtered out (called screening), skimmers remove floating grease and oil, and floating debris is shredded or ground.

A. Tertiary Treatment B. Secondary Treatment C. Quarter Treatment D. Primary Treatment 12. Treatment involves the addition of chemicals, filtration (using fine sand or charcoal), chlorination, and sometimes distillation.

A. Tertiary Treatment B. Secondary Treatment C. Quarter Treatment D. Primary Treatment 13. The main source of biological pollution is A. environmental waste.

B. animal dungs C. humans waste product D. Aquatic remnants 14. Infections involve marked hemorrhaging and serous effusions (fluid that has escaped from blood or lymphatic vessels) in various organs and body cavities and are frequently fatal.

A. Anthrax B. Botulism C. Smallpox D. Poisoning 15. Water safety threats A. Category C B. Category A C. Category B D. Category D

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16. A symbiont could be a(n): A. commensal B. opportunist C. parasite D. all of the above 17. The greatest number and variety of indigenous microbiota of the human body live in or on the: A. colon B, genitourinary tract C. mouth D. skin 1. Escherichia coli living in the human colon ca be considered to be a: A. endosymbiont B. opportunist C. symbiont in a mutualistic relationship D. all of the above 2. Which of the following sites of the human body does not have indigenous microbiota?

A. bloodstream B. colon C. distal urethra D. vagina 3. Which of the following would be present in highest numbers in the indigenous microbiota of the human mouth?

A. ꭤ-hemolytic streptococci B. ꞵ- hemolytic streptococci C. Candida albicans D. Staphylococcus aureus 4. Which of the following would be present in highest numbers in the indigenous microbiota of the skin?

A. C. Albicans B. coagulase-negative staphylococci C. Enterococcus spp.

D. E. coli 5. The indigenous microbiota of the external ear canal is most like the indigenous microbiota of the: A. colon B. mouth C. skin D. distal urethra 6. Which of the following are least likely to play a role in the nitrogen cycle?

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C. nitrogen-fixing bacteria D. bacteria living in the root nodules of legumes 7. Microorganisms are used in which of the following industries?

A. antibiotic B. chemical C. food, beer, and wine D. all of the above 8.

The term that describes a symbiotic relationship in which two different microorganisms occupy the same ecological niche, but have absolutely no effect on each other is: A. commensalism B. mutualism C. neutralism D. parasitism

9.

Method of breeding that allows only those individual organisms with desired characteristics to produce the next generation (“Super Cow”) A. Out breeding B. Selective breeding C. Close breeding D. hybrid breeding

10. Breeding technique that involves crossing dissimilar individuals to bring together the best traits of both organisms.

A. Selective breeding B. hybridization C. inbreeding D. genetic engineering 11. The transfer of a gene from the DNA of one organism into another organism, in order to produce an organism with desired traits.

A. Selective breeding B. hybridization C. inbreeding D. genetic engineering

12. A technology applied to living organisms A. Industrial technology B. microtechnology C. biotechnology D. Power technology 13. It can produce many copies of a specific target segment of DNA A. gene therapy B. PCR (polymerase chain reaction) C. GM foods (genetically modified foods) D. DNA fingerprint A Self-regulated Learning Module

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ACTIVITY 9 IMMUNOLOGY I.

OBJECTIVE

The students are expected to correctly discuss what body’s defenses against infections are; differentiate innate from acquired immunity; artificial from natural immunity; and to describe the different mechanisms under each categories of immunity.

II.

DISCUSSION

Immunology is a science that deals with the immune system and the cell-mediated and humoral aspects of immunity and immune response. Our body responds to various microbial invaders in either non-specific or specific ways. Non-specific immunity is our 1st fine of defense and second line of defenses. The first line of defense includes nonspecific physical and chemical defenses like the skin. Mucous membranes, stomach acid, lysozyme in tears; they are non-specific natural barriers which restrict entry of pathogens. The second line of defense is innate non-specific immune defenses that provide rapid local response to pathogens after it has entered the host.

Examples are the actions of the phagocytes (macrophages and neutrophils), protective proteins like cytokines, fever, NK cells, interferon, and inflammation.

The specific (acquired) immunity is considered as the third line of defense, also known as adaptive immunity.

It deals with the production of specific proteins against particular microbes. It is antigenspecific (acquired) immunity that specifically targets and attacks invaders that get past the first two lines of defense. The protective proteins are called antibodies or the immunoglobulins, produced by the B- cells or B Lymphocytes as a response to foreign materials to the body called antigens or the immunogens.

III.

MATERIALS Pencil, PPEs (lab gown), Reference materials

IV.

Procedures A. Draw and label the following: 1. Typical antibody structure

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2. A dimer (Immunoglobulin A)

3.

A pentamer (immunoglobulin M)

4.

A neutrophil

5.

Eosinophil

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6.

Basophil

7. Phases of phagocytosis

V.

Questions for research

1. Fill up the table regarding the different types of leukocytes Type

Normal value (%) in peripheral blood

Functions

A. Granulocytes (polymorphonuclear leukocytes)- 5,000-10,000/mm3 1.

Neutrophils

2. Basophils

3. Eosinophils

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B. Agranulocytes (produced in lymphatic system; non-granular under microscope) Monocytes

Lymphocytes

2. Different antibodies (immunoglobulins-GAMED)

Criteria

Ig G

Ig A

Ig M

Ig E

Ig D

Form Molecular weight Description % in total Ig Concentration in serum Number of antigenic binding sites Function/s

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3. What are the four major subdivisions of the immune system? a. b. c. d.

2. What are the 6 tissues and organs of the immune system a. b. c . d

e

f 5. Differentiate non-specific from specific immunity Non-specific

Specific

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6. Differentiate innate from acquired immunity -

Inherited-

-

Acquired-

7. Difference between natural and artificial acquired immunity A. natural-

B. Artificial-

8. Difference between active and passive immunity ActivePassive

9. Differentiate cell-mediated (T-cells) immunity from Antibody-mediated immunity a. Cell mediated-

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b. Antibody-mediated-

Define the following: 10. Active immunity –

11. Passive immunity –

12. Natural active immunity –

13. Natural passive immunity –

14. Artificial active immunity –

15. Artificial passive immunity –

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Evaluation Tool________________________________________________________ 1. What is the new learning that added into my knowledge from this course? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 2. What are the topics that have given me a great impact that relates in my course? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 3. What lesson or activity did I enjoy most? Why? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 4. What do you think is the topic that can help you the most and Why? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 5. What is the least topic that you think is not most needed? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________

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References Book Gupte S.,” The Shirt Textbook of Medical Microbiology including Parasitology” 10th edition., 2019., ISBN : 978-81-8448-840-1 Bhatia R., Ichhpujani R., “ Essentials of Medical Microbiology” 4th edition., 2008., Jitendar P Vij Jaypee Brothers Medical Publishers (P) Ltd B-3 EMCA House, 23/23B Ansari Road

Betsy T., Keogh J., “ Microbiology Demystified”., 2005., The McGraw-Hill Companies, Inc.

Internet NIH.

(2010,

October

6).

What

are

microbes?.

Retrieved

from:

https://www.ncbi.nlm.nih.gov/books/NBK279387/ Structure

of

Prokaryotes.

Retrieved

from:

https://courses.lumenlearning.com/boundless

biology/chapter/structure-of prokaryotes/#:~:text=Prokaryotes%20are%20unicellular%20organisms%20that,the%20cell%20ca lled%20the%20nucleoid Protozoology.Retrievedfrom:https://en.wikipedia.org/wiki/Protozoology#:~:text=Protozoology%20is%20th e%20study%20of,of%20the%20eukaryotes%20has%20improved Mycology.Retrievedfrom:https://en.wikipedia.org/wiki/Mycology#:~:text=Mycology%20is%20the%20branc h%20of,such%20as%20toxicity%20or%20infection Virology. Retrieved from: https://en.wikipedia.org/wiki/Virology Bacteriology.Retrievedfrom:https://en.wikipedia.org/wiki/Bacteriology#:~:text=Bacteriology%20is%20the% 20branch%20and,and%20characterization%20of%20bacterial%20species Protozoa.Retrievedfrom:https://en.wikipedia.org/wiki/Protozoa#:~:text=Protozoa%20(also%20protozoan% 2C%20plural%20protozoans,or%20organic%20tissues%20and%20debris

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Fungus. Retrieved from: https://en.wikipedia.org/wiki/Fungus Eukaryote.Retrievedfrom:https://en.wikipedia.org/wiki/Eukaryote#:~:text=Eukaryotes%20(%2Fju%CB%90 %CB%88k,%22%20or%20%22kernel%22) Algae.Retrievedfrom:https://www.yourdictionary.com/algae#:~:text=The%20definition%20of%20algae%2 0is,and%20chlorophyll%20to%20make%20food Virus. Retrieved from: https://en.wikipedia.org/wiki/Virus Bacteria. Retrieved from: https://en.wikipedia.org/wiki/Bacteria Betsy,

T.,

Keogh,

J.

(n.d.).

Microbiology

Demystified.

Retrieved

from:

file:///F:/Microbiology%20Demystified%20-%20Tom%20Betsy,%20James%20Keogh.pdf Engelkirk, P., Duben-Engelkirk, J. (2015). Burton’s Microbiology for the Health Sciences (Tenth Edition).

Wolters Kluwer Health.

1.WHO Surgical Care at the District Hospital Manual 2003 2. WHO Management of Solid Health-Care Waste at Primary Health-Care Centres : a decision making guide 2005; 3. Burton’s th

Microbiologyfor the Health Sciences 10 Edition; 4. World wide web(www) microbiology for allied health sciences.

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