TEST BANK for Medical Parasitology 7th Edition Leventhal Ruth Leventhal, Cheadle

Medical Parasitology 7th Edition Leventhal Test Bank Chapter 1. Introduction 1. In a general nematode parasite’s life cycle, the host may ingest a fertile egg. This stage of the life cycle is referred to as the: a. Definitive host phase b. Diagnostic stage c. Infective stage d. Method of infection

2. A parasite that lives inside a host is referred to as a(n): a. Accidental parasite b. Ectoparasite c. Endoparasite d. Facultative parasite

3. Zoonosis is a term used to describe humans’ relationship with a(n): a. Accidental parasite b. Ectoparasite c. Endoparasite d. Facultative parasite

4. An animal that harbors a parasite that can also infect humans is referred to as a(n): a. Definitive host b. Intermediate host c. Reservoir host d. Transport host

5. The host in which the parasite reaches sexual or reproductive maturity is referred to as a(n): a. Definitive host b. Intermediate host

c. Reservoir host d. Transport host

Answer Key for Chapter 1. Introduction 1. In a general nematode parasite’s life cycle, the host may ingest a fertile egg. This stage of the life cycle is referred to as the: a. Definitive host phase b. Diagnostic stage c. Infective stage d. Method of infection ANS: C RATIONALE: This is the stage of the life cycle at which the parasite is capable of entering and developing within the host. It is a required part of the life cycle of that parasite.

KEY: Introduction: parasite definitions/life cycles | Cognitive level: recall

2. A parasite that lives inside a host is referred to as a(n): a. Accidental parasite b. Ectoparasite c. Endoparasite d. Facultative parasite

ANS: C RATIONALE: Endoparasites live inside the host. Ectoparasites live on the outside of the host.

Facultative parasites can live as well outside the host as inside the host; host infection usually occurs accidentally. Other accidental parasites may include parasites that usually infect other animals.

KEY: Introduction: parasite definitions/life cycles | Cognitive level: recall

3. Zoonosis is a term used to describe humans’ relationship with a(n): a. Accidental parasite b. Ectoparasite c. Endoparasite d. Facultative parasite ANS: A RATIONALE: Zoonosis is an accidental infection with a parasite that usually parasitizes animals. Endoparasites live inside the host. Ectoparasites live outside the host. Facultative parasites can live as well outside the host as inside the host; host infection usually occurs accidentally.

KEY: Introduction: parasite definitions/life cycles | Cognitive level: recall

4. An animal that harbors a parasite that can also infect humans is referred to as a(n): a. Definitive host b. Intermediate host c. Reservoir host d. Transport host ANS: C RATIONALE: Reservoir hosts harbor parasites that are also infective for humans. Infections occur when humans encounter infected animals or infective forms related to that parasite’s life cycle.

KEY: Introduction: parasite-host relationships | Cognitive level: recall

5. The host in which the parasiteTreEaS chTeB sA seNxK uaSl E orLrL epEroRd.uC ctO ivM e maturity is referred to as a(n): a. Definitive host b. Intermediate host

c. Reservoir host d. Transport host ANS: A RATIONALE: The definitive host harbors the parasite in its complete form, which promotes continuance of the parasite’s life cycle. A reservoir host also serves as a definitive host.

KEY: Introduction: parasite-host relationships | Cognitive level: recall

Chapter 2. Nematoda

1. A clinical sign that may suggest the presence of a filarial nematode infection is: a. Diarrhea b. Eosinophilia c. Jaundice d. Microcytic anemia

2. The nematode infection that may become more severe through ingestion of infective eggs, especially in infected infants, is: a. Ancylostoma duodenale b. Enterobius vermicularis c. Strongyloides stercoralis d. Trichinella spiralis

3. In the Ascaris lumbricoides life cycle, after eggs are ingested, the next stage in the life cycle that must occur before a mature adult can live in the host’s intestine is called the: a. Diagnostic stage b. Infective stage c. Liver-lung migration d. Method of infection

4. Patients who have heavy infections with Necator americanus may exhibit all of the following symptoms EXCEPT: a. Diarrhea b. Larval dermatitis c. Macrocytic anemia d. Microcytic anemia

Multiple Choice Questions - Chapter 2

5. The nematode egg that appears as a barrel-shaped structure with clear polar plugs at each end of the egg belongs to: a. Ascaris lumbricoides b. Enterobius vermicularis c. Strongyloides stercoralis d. Trichuris trichiura

6. A slender round worm measuring 25 cm was recovered from a toilet following a child’s trip to the bathroom. The specimen most likely is: a. Ascaris lumbricoides b. Enterobius vermicularis c. Strongyloides stercoralis d. Trichuris trichiura

7. A 7-year-old boy’s CBC revealed a microcytic anemia with eosinophilia during an office visit for symptoms of diarrhea. The most likely parasite involved in the infection is: a. Enterobius vermicularis b. Necator americanus c. Trichuris trichiura d. Wuchereria bancrofti

8. Which of the following infections is not diagnosed by finding eggs or lava in fecal specimens? a. Ascaris lumbricoides b. Necator spp. c. Trichinella spiralis d. Trichuris trichiura

9. Which of the following parasitic diseases is a zoonosis? a. Ascaris lumbricoides b. Dracunculus medinensis c. Strongyloides stercoralis Multiple Choice Questions - Chapter 2

d. Trichinella spiralis

10. Cutaneous larvamigrans is caused by: a. Ascaris lumbricoides b. Necator americanus c. Strongyloides stercoralis d. Toxocara canis

11. The nematode parasite that may complete its life cycle without leaving the host is: a. Ascaris lumbricoides b. Necator americanus c. Strongyloides stercoralis d. Toxocara canis

12. All of the following have life cycles that require larval lung migrations EXCEPT: a. Ascaris lumbricoides b. Necator americanus c. Strongyloides stercoralis d. Trichuris trichiura

13. The diagnostic form recovered in feces in Strongyloides stercoralis infections is the: a. Adult worm b. Egg c. Filariform larva d. Rhabditiform larva

14. A soldier returning from Iraq noticed a blister above his ankle that subsequently opened while he was swimming in his family pool. On further examination, he noticed a worm in the open blister. The possible parasite in this lesion is: a. Ancylostoma duodenale Multiple Choice Questions - Chapter 2

b. Dracunculus medinensis c. Toxocara canis d. Visceral larva migrans

15. All of the following infections are diagnosed by finding microfilaria in blood EXCEPT: a. Wuchereria bancrofti b. Onchocerca volvulus c. Loa loa d. Brugia malayi

16. A microfilaria recovered in a blood sample from a patient from Vietnam had two nuclei at the tip of the tail. The worm was enclosed in a sheath. This parasite is: a. Brugia malayi b. Loa loa c. Onchocerca volvulus d. Wuchereria bancrofti

17. An immigrant from central Africa is exhibiting transient subcutaneous swelling in the arm.

A blood smear revealed a sheathed microfilaria with a single row of nuclei present in the posterior of the parasite. The most likely identification is: a. Brugia malayi b. Loa loa c. Onchocerca volvulus d. Wuchereria bancrofti

18. The diagnosis of Enterobius vermicularis infection is accomplished by observing: a. Eggs in feces b. Eggs recovered from the perianal region c. Larva in feces d. Trophozoites in feces

Multiple Choice Questions - Chapter 2

19. The rhabditiform larva of Strongyloides stercoralis has a: a. Long buccal cavity b. Sheath c. Large genital primordium d. Notched tail

20. Closed fecal sanitation systems had directly led to the reduction of all the following nematode infections EXCEPT: a. Ascariasis b. Hookworm disease c. Strongyloidiasis d. Trichinosis

21. The diagnostic form of this parasite appears as an oval thin-shelled egg with a clear area around the eight-celled immature embryo. This parasite is: a. Ascaris lumbricoides b. Enterobius vermicularis c. Hookworm d. Trichuris trichiura

22. The nematode infection that is acquired by ingesting a Cyclops (water flea) is: a. Dracunculus medinensis b. Enterobius vermicularis c. Necator americanus d. Trichinella spiralis

23. Which of the following organisms or infections could be transmitted in the laboratory? a. Ascaris lumbricoides—Ascariasis b. Enterobius vermicularis—pinworm infection c. Strongyloides stercoralis—Strongyloidiasis d. Trichuris trichiura—whipworm infection Multiple Choice Questions - Chapter 2

24. Which of the following parasitic diseases can cause blindness? a. Brugia malayi b. Loa loa c. Onchocerca volvulus d. Wuchereria bancrofti

25. Elephantiasis is a clinical symptom associated with: a. Brugia malayi b. Loa loa c. Onchocerca volvulus d. Strongyloides stercoralis

26. Name the parasite shown in the following image:

a. Ascaris lumbricoides egg b. Enterobius vermicularis egg c. Hookworm egg d. Trichuris trichiura egg

27. Name the parasite shown in the following image:

Multiple Choice Questions - Chapter 2

a. Ascaris lumbricoides egg b. Enterobius vermicularis egg c. Hookworm egg d. Trichuris trichiura egg

28. Name the parasite shown in the following image:

a. Ascaris lumbricoides egg b. Enterobius vermicularis egg c. Hookworm egg d. Trichuris trichiura egg

29. Name the parasite shown in the following image:

a. Ascaris lumbricoides egg b. Enterobius vermicularis egg c. Hookworm egg d. Trichuris trichiura egg

Multiple Choice Questions - Chapter 2

30. Name the parasite shown in the following image:

a. Wuchereria bancrofti—microfilaria b. Filariform larva c. Pinworm—female d. Rhabditiform larva

Multiple Choice Questions - Chapter 2

Answer Key for Chapter 2. Nematoda 1. A clinical sign that may suggest the presence of a filarial nematode infection is: a. Diarrhea b. Eosinophilia c. Jaundice d. Microcytic anemia ANS: B RATIONALE: Migrating nematodes, especially filarial parasites, are usually associated with blood or tissue eosinophilia.

KEY: Nematoda: life cycle/clinical symptoms | Cognitive level: correlation

2. The nematode infection that may become more severe through ingestion of infective eggs, especially in infected infants, is: a. Ancylostoma duodenale b. Enterobius vermicularis c. Strongyloides stercoralis d. Trichinella spiralis ANS: B RATIONALE: Enterobius vermicularis infections become more severe due to the pruritus caused by new eggs released by dying females, which leads to autoreinfection through ingestion of these new eggs.

KEY: Nematoda: life cycle | Cognitive level: correlation

3. In the Ascaris lumbricoides life cycle, after eggs are ingested, the next stage in the life cycle that must occur before a mature adult can live in the host’s intestine is called the: a. Diagnostic stage b. Infective stage c. Liver-lung migration d. Method of infection ANS: C RATIONALE: The liver-lung migration phase of the Ascaris lumbricoides life cycle occurs as the larva form migrates from the intestine to the lungs before returning to the intestine to become a mature adult worm. See life cycle, p. 17.

Multiple Choice Questions - Chapter 2

KEY: Nematoda: life cycle | Cognitive level: recall

4. Patients who have heavy infections with Necator americanus may exhibit all of the following symptoms EXCEPT: a. Diarrhea b. Larval dermatitis c. Macrocytic anemia d. Microcytic anemia ANS: C RATIONALE: Macrocytic anemia does not occur because this disease is caused by a vitamin B12 deficiency. Hookworm infection is a cause of microcytic anemia, which may result from reduced plasma iron levels due to red blood cell loss; heavy worm burdens may result in 100 ml of blood loss per day.

KEY: Nematoda: disease condition | Cognitive level: correlation

5. The nematode egg that appears as a barrel-shaped structure with clear polar plugs at each end of the egg belongs to: a. Ascaris lumbricoides b. Enterobius vermicularis c. Strongyloides stercoralis d. Trichuris trichiura ANS: D RATIONALE: Trichuris trichiura eggs appear as a barrel-shaped structure with clear polar plugs at each end. See drawing and photograph.

KEY: Nematoda: diagnostic form | Cognitive level: recall

6. A slender round worm measuring 25 cm was recovered from a toilet following a child’s trip to the bathroom. The specimen most likely is: a. Ascaris lumbricoides b. Enterobius vermicularis c. Strongyloides stercoralis d. Trichuris trichiura Multiple Choice Questions - Chapter 2

ANS: A RATIONALE: Ascaris lumbricoides measure 22 to 35 cm in length and are often recovered in feces. The adult worm is active and may migrate up the esophagus as well. See life cycle, p. 17.

KEY: Nematoda: diagnostic form | Cognitive level: correlation

7. A 7-year-old boy’s CBC revealed a microcytic anemia with eosinophilia during an office visit for symptoms of diarrhea. The most likely parasite involved in the infection is: a. Enterobius vermicularis b. Necator americanus c. Trichuris trichiura d. Wuchereria bancrofti ANS: B RATIONALE: Necator spp. often causes iron-deficient anemia. Diarrhea and eosinophilia are common symptoms.

KEY: Nematoda: disease symptoms | Cognitive level: correlation

8. Which of the following infections is not diagnosed by finding eggs or lava in fecal specimens? a. Ascaris lumbricoides b. Necator spp. c. Trichinella spiralis d. Trichuris trichiura ANS: C RATIONALE: Trichinella spiralis larvae are ingested in undercooked meat. Freed larvae invade muscle tissue and encyst. Diagnosis is based on finding encysted larvae in biopsied muscle.

KEY: Nematoda: diagnosis | Cognitive level: recall

9. Which of the following parasitic diseases is a zoonosis? a. Ascaris lumbricoides b. Dracunculus medinensis c. Strongyloides stercoralis Multiple Choice Questions - Chapter 2

d. Trichinella spiralis ANS: D RATIONALE: Trichinella spiralis infection is a zoonosis. See life cycle, p. 23; the normal hosts include carnivorous mammals.

KEY: Nematoda: life cycle | Cognitive level: recall

10. Cutaneous larva migrans is caused by: a. Ascaris lumbricoides b. Necator americanus c. Strongyloides stercoralis d. Toxocara canis ANS: B RATIONALE: Free-living filariform larvae of Necator spp. may invade broken skin. See life cycle, p. 19.

KEY: Nematoda: life cycle | Cognitive level: correlation

11. The nematode parasite that may complete its life cycle without leaving the host is: a. Ascaris lumbricoides b. Necator americanus c. Strongyloides stercoralis d. Toxocara canis ANS: C RATIONALE: Strongyloides stercoralis is parthenogenic; therefore, fertile eggs hatch inside the host and may become infective without leaving the host.

KEY: Nematoda: life cycle, p. 21 | Cognitive level: recall

12. All of the following have life cycles that require larval lung migrations EXCEPT: a. Ascaris lumbricoides b. Necator americanus c. Strongyloides stercoralis d. Trichuris trichiura

Multiple Choice Questions - Chapter 2

ANS: D RATIONALE: Trichuris trichiura eggs are swallowed and hatch to become mature adults in the intestine. All of the parasites mentioned in choices A through C have migrations through the lungs in order to complete the life cycle. See individual life cycle diagrams; A=p. 17, B=p. 19, C=p. 21, D=p. 15.

KEY: Nematoda: life cycle | Cognitive level: recall

13. The diagnostic form recovered in feces in Strongyloides stercoralis infections is the: a. Adult worm b. Egg c. Filariform larva d. Rhabditiform larva ANS: D RATIONALE: Eggs released by the adult worm hatch in the intestinal mucosa, releasing immature rhabditiform larvae.

KEY: Nematoda: life cycle, p. 21 | Cognitive level: recall 14. A soldier returning from Iraq noticed a blister above his ankle that subsequently opened while he was swimming in his family pool. On further examination, he noticed a worm in the open blister. The possible parasite in this lesion is: a. Ancylostoma duodenale b. Dracunculus medinensis c. Toxocara canis d. Visceral larva migrans ANS: B RATIONALE: The soldier was returning from an endemic area for D. medinensis. This parasite produces a blister that ruptures in water, so larvae may be released.

KEY: Nematoda: life cycle, p. 25 | Cognitive level: correlation

15. All of the following infections are diagnosed by finding microfilaria in blood EXCEPT: a. Wuchereria bancrofti b. Onchocerca volvulus c. Loa loa d. Brugia malayi Multiple Choice Questions - Chapter 2

ANS: B RATIONALE: Microfilaria of Onchocerca volvulus are found in the dermis, with adults residing in subcutaneous nodules.

KEY: Nematoda: life cycle, p. 27; Filariae | Cognitive level: recall

16. A microfilaria recovered in a blood sample from a patient from Vietnam had two nuclei at the tip of the tail. The worm was enclosed in a sheath. This parasite is: a. Brugia malayi b. Loa loa c. Onchocerca volvulus d. Wuchereria bancrofti ANS: A RATIONALE: Microfilariae are identified by examining their morphologic features. The presence or absence of structures such as sheaths and nuclei in the posterior end of the parasite are characteristics used to identify microfilaria. Brugia malayi may be identified when two nuclei are found at the tip of the parasite’s tail that is enclosed in a sheath.

KEY: Nematoda: diagnostic form | Cognitive level: application

17. An immigrant from central Africa is exhibiting transient subcutaneous swelling in the arm.

A blood smear revealed a sheathed microfilaria with a single row of nuclei present in the posterior of the parasite. The most likely identification is: a. Brugia malayi b. Loa loa c. Onchocerca volvulus d. Wuchereria bancrofti ANS: B RATIONALE: Microfilariae are identified by examining their morphologic features. The presence or absence of structures such as sheaths and nuclei in the posterior end of the parasite are characteristics used to identify microfilaria. Loa loa is identified when a sheathed organism with a single row of nuclei extending to the tip of the tail of the parasite is observed.

KEY: Nematoda: diagnostic form | Cognitive level: application

Multiple Choice Questions - Chapter 2

18. The diagnosis of Enterobius vermicularis infection is accomplished by observing: a. Eggs in feces b. Eggs recovered from the perianal region c. Larva in feces d. Trophozoites in feces ANS: B RATIONALE: The female worm leaves the anus and dies, releasing eggs into the perianal region.

KEY: Nematoda: identification | Cognitive level: recall

19. The rhabditiform larva of Strongyloides stercoralis has a: a. Long buccal cavity b. Sheath c. Large genital primordium d. Notched tail ANS: C RATIONALE: Strongyloides stercoralis larvae can be identified when a large genital primordium is noted. A short buccal cavity is also noted. The parasite’s eggs hatch in the intestinal mucosa of the host. Larvae are noted in fecal specimens.

KEY: Nematoda: identification | Cognitive level: correlation

20. Closed fecal sanitation systems had directly led to the reduction of all of the following nematode infections EXCEPT: a. Ascariasis b. Hookworm disease c. Strongyloidiasis d. Trichinosis ANS: D RATIONALE: Trichinosis is acquired by eating infected pork. The other parasitic infections have fecal-oral components in the life cycle. Sanitary systems reduce human exposure to contaminated feces.

KEY: Nematoda: identification | Cognitive level: correlation

Multiple Choice Questions - Chapter 2

21. The diagnostic form of this parasite appears as an oval thin-shelled egg with a clear area around the eight-celled immature embryo. This parasite is: a. Ascaris lumbricoides b. Enterobius vermicularis c. Hookworm d. Trichuris trichiura ANS: C RATIONALE: The described egg is seen in feces in hookworm infections.

KEY: Nematoda: identification | Cognitive level: recall

22. The nematode infection that is acquired by ingesting a Cyclops (water flea) is: a. Dracunculus medinensis b. Enterobius vermicularis c. Necator americanus d. Trichinella spiralis ANS: A RATIONALE: Dracunculus medinensis infection is acquired by drinking water containing an infected water flea.

KEY: Nematoda: life cycle, p. 25 | Cognitive level: recall

23. Which of the following organisms or infections could be transmitted in the laboratory? a. Ascaris lumbricoides—Ascariasis b. Enterobius vermicularis—pinworm infection c. Strongyloides stercoralis—Strongyloidiasis d. Trichuris trichiura—whipworm infection ANS: B RATIONALE: Only pinworm eggs become infective after being released into the local environment (in 4 to 6 hours). All others require exposure to soil before embryonating.

KEY: Nematoda: life cycle, p. 13 | Cognitive level: correlation

Multiple Choice Questions - Chapter 2

24. Which of the following parasitic diseases can cause blindness? a. Brugia malayi b. Loa loa c. Onchocerca volvulus d. Wuchereria bancrofti ANS: C RATIONALE: Although Loa loa is referred to as the eyeworm, it does not produce blindness because it does not invade other eye structures (only blood vessels) as do the microfilariae of Onchocerca volvulus.

KEY: Nematoda: disease manifestations | Cognitive level: correlation

25. Elephantiasis is a clinical symptom associated with: a. Brugia malayi b. Loa loa c. Onchocerca volvulus d. Strongyloides stercoralis ANS: A RATIONALE: Brugia malayi and Wuchereria bancrofti microfilaria both cause elephantiasis in long-standing infections by obstructing lymphatic ducts. Loa loa and Onchocerca volvulus live in subcutaneous locations; microfilaria moves through blood vessels, causing pathology in the face and eyes. Strongyloides stercoralis lives in the intestine, and larval forms migrate through the liver and lungs, eventually returning to the GI tract.

KEY: Nematoda: pathology and life cycle | Cognitive level: correlation

26. Name the parasite shown in the following image: a. Ascaris lumbricoides egg b. Enterobius vermicularis egg c. Hookworm egg d. Trichuris trichiura egg ANS: A RATIONALE: This view is of an Ascaris lumbricoides egg. The heavy, albuminous outer-shell coating indicates that this is a fertile egg.

KEY: Nematoda: parasite identification | Cognitive level: recall

Multiple Choice Questions - Chapter 2

27. Name the parasite shown in the following image: a. Ascaris lumbricoides egg b. Enterobius vermicularis egg c. Hookworm egg d. Trichuris trichiura egg ANS: C RATIONALE: This view is of a hookworm egg. Hookworm eggs cannot be identified to the species level. The final identification relies on recovering the adult worm.

KEY: Nematoda: parasite identification | Cognitive level: recall

28. Name the parasite shown in the following image: a. Ascaris lumbricoides egg b. Enterobius vermicularis egg c. Hookworm egg d. Trichuris trichiura egg ANS: B RATIONALE: This view is of an Enterobius vermicularis (pinworm) egg. These eggs have the characteristic flattened side.

KEY: Nematoda: parasite identification | Cognitive level: recall

29. Name the parasite shown in the following image: a. Ascaris lumbricoides egg b. Enterobius vermicularis egg c. Hookworm egg d. Trichuris trichiura egg ANS: D RATIONALE: This view is of a Trichuris trichiura (whipworm) egg. This egg has the characteristic tray shape.

KEY: Nematoda: parasite identification | Cognitive level: recall

Multiple Choice Questions - Chapter 2

30. Name the parasite shown in the following image: a. Wuchereria bancrofti—microfilaria b. Filariform larva c. Pinworm—female d. Rhabditiform larva ANS: D RATIONALE: This view is the larval form seen in feces in Strongyloides stercoralis infections.

Eggs resembling those of hookworms may occasionally be found as well, but the usual diagnostic form is the rhabditiform larva.

KEY: Nematoda: parasite identification | Cognitive level: recall

Multiple Choice Questions - Chapter 2

Chapter 3. Cestoda

1. Which of the following cestode infections can increase through autoreinfection? a. Diphyllobothrium latum b. Echinococcus granulosa c. Hymenolepis nana d. Taenia solium

2. Consumption of raw or undercooked beef is associated with: a. Taenia saginata b. Taenia solium c. Trichinella spiralis d. Dipylidium carninum

3. The cestode that produces an operculated egg is: a. Diphyllobothrium latum b. Echinococcus granulosa c. Hymenolepis nana d. Taenia solium

4. The definitive host for Echinococcus granulosus is a: a. Cow b. Dog c. Human d. Sheep

5. For which of the following can humans serve as both the definitive and intermediate host? a. Diphyllobothrium latum b. Echinococcus granulosa c. Taenia saginata Multiple Choice Questions - Chapter 3

d. Taenia solium

6. Which of the following tapeworm infections is associated with vitamin B12 deficiency macrocytic anemia? a. Diphyllobothrium latum b. Hymenolepis nana c. Taenia saginata d. Taenia solium

7. Several tapeworm segments recovered in a routine fecal concentration procedure were found to have 7 to 12 lateral uterine branches. This parasite is: a. Taenia solium b. Taenia saginata c. Diphyllobothrium latum d. Dipylidium caninum

8. Humans can become an accidental zoophytic host for which of the following if an infected flea is ingested? a. Dipylidium caninum b. Echinococcus granulosus c. Spirometra spp. d. Taenia solium

9. The first intermediate host in the Diphyllobothrium latum life cycle is a: a. Copepod b. Fish c. Flea d. Pig

Multiple Choice Questions - Chapter 3

10. Identify the parasite shown in the following view:

a. Diphyllobothrium latum b. Echinococcus granulosa c. Hymenolepis nana d. Taenia saginata

11. The structural component in tapeworms that contains the reproductive organs is called the: a. Onchosphere b. Proglottid c. Scolex d. Strobila

12. Identify the parasite shown in the following view:

a. Ascaris lumbricoides b. Taenia saginata c. Taenia solium d. Either b or c e. None of these

Multiple Choice Questions - Chapter 3

Answer Key for Chapter 3. Cestoda

1. Which of the following cestode infections can increase through autoreinfection? a. Diphyllobothrium latum b. Echinococcus granulosa c. Hymenolepis nana d. Taenia solium ANS: C RATIONALE: Hymenolepis nana eggs are infective when released, so they may hatch in the GI tract.

KEY: Cestoda: life cycle | Cognitive level: correlation

2. Consumption of raw or undercooked beef is associated with: a. Taenia saginata b. Taenia solium c. Trichinella spiralis d. Dipylidium carninum ANS: A RATIONALE: T. saginata, the beef tapeworm, is acquired by ingesting undercooked beef. T. solium is acquired by eating undercooked pork.

KEY: Cestoda: life cycle | Cognitive level: correlation

3. The cestode that produces an operculated egg is: a. Diphyllobothrium latum b. Echinococcus granulosa c. Hymenolepis nana d. Taenia solium ANS: A RATIONALE: D. latum produces an operculated egg.

KEY: Cestoda: morphology | Cognitive level: recall

Multiple Choice Questions - Chapter 3

4. The definitive host for Echinococcus granulosus is a: a. Cow b. Dog c. Human d. Sheep ANS: B RATIONALE: The dog and other wild canines harbor the adult tapeworm of E. granulosus.

Humans and sheep serve as accidental intermediate hosts.

KEY: Cestoda: life cycle | Cognitive level: recall

5. For which of the following can humans serve as both the definitive and intermediate host? a. Diphyllobothrium latum b. Echinococcus granulosa c. Taenia saginata d. Taenia solium ANS: D RATIONALE: T. solium eggs will hatch in humans with larva migrating from the intestine to other body sites, causing the condition known as cysticercosis. Encysted larvae in undercooked pork lead to tapeworm disease if ingested by humans.

KEY: Cestoda: life cycle | Cognitive level: correlation

6. Which of the following tapeworm infections is associated with vitamin B12 deficiency macrocytic anemia? a. Diphyllobothrium latum b. Hymenolepis nana c. Taenia saginata d. Taenia solium ANS: A RATIONALE: D. latum worms compete with the host for vitamin B12, which can lead to macrocytic anemia in some individuals, especially Scandinavians.

KEY: Cestoda: disease symptoms | Cognitive level: correlation Multiple Choice Questions - Chapter 3

7. Several tapeworm segments recovered in a routine fecal concentration procedure were found to have 7 to 12 lateral uterine branches. This parasite is: a. Taenia solium b. Taenia saginata c. Diphyllobothrium latum d. Dipylidium caninum ANS: A RATIONALE: Taenia spp. eggs are identical, so typical segments or scolex (following treatment) is needed to properly identify this species.

KEY: Cestoda: identification | Cognitive level: correlation

8. Humans can become an accidental zoophytic host for which of the following if an infected flea is ingested? a. Dipylidium caninum b. Echinococcus granulosus c. Spirometra spp. d. Taenia solium ANS: A RATIONALE: Only D. caninum has a flea as an intermediate host in its life cycle.

KEY: Cestoda: life cycle | Cognitive level: recall

9. The first intermediate host in the Diphyllobothrium latum life cycle is a: a. Copepod b. Fish c. Flea d. Pig ANS: A RATIONALE: A copepod ingests a free-living coracidium larva, which is, in turn, ingested by a fish that becomes the second intermediate host. Humans ingest encysted larval forms in uncooked fish.

Multiple Choice Questions - Chapter 3

KEY: Cestoda: life cycle | Cognitive level: recall

10. Identify the parasite shown in the following view: a. Diphyllobothrium latum b. Echinococcus granulosa c. Hymenolepis nana d. Taenia saginata ANS: A RATIONALE: This view is a Diphyllobothrium latum egg. It is the only operculated cestode egg.

KEY: Cestoda: identification | Cognitive level: recall

11. The structural component in tapeworms that contains the reproductive organs is called the: a. Onchosphere b. Proglottid c. Scolex d. Strobila ANS: B RATIONALE: The proglottid, also called the segment, is the structure that contains both the male and female reproductive organs. The strobila is the entire body of the tapeworm, which may contain many proglottids.

KEY: Cestoda: tapeworm structure | Cognitive level: correlation

12. Identify the parasite shown in the following view: a. Ascaris lumbricoides b. Taenia saginata c. Taenia solium d. Either b or c e. None of these ANS: D

Multiple Choice Questions - Chapter 3

RATIONALE: The eggs of both Taenia saginata and Taenia solium look alike. Species differentiation requires recovery of either the scolex or proglottid to correctly identify the species of this worm.

KEY: Cestoda: tapeworm identification | Cognitive level: recall and correlation

Multiple Choice Questions - Chapter 3

Chapter 4. Digenea

1. If a U.S. citizen never leaves the United States, which of the following is the only disease that he or she could acquire? a. Clonorchis sinensis b. Fasciolopsis buski c. Fasciola hepatica d. Paragonimus westermani

2. The egg of one trematode species can be recovered in urine. This parasite is: a. Clonorchis sinensis b. Heterophyes heterophyes c. Schistosoma haematobium d. Schistosoma japonicum

3. For which of the following is sputum useful in the diagnosis of parasitic infection? a. Clonorchis sinensis b. Fasciola hepatica c. Paragonimus westermani d. Schistosoma mansoni

4. Two helminth eggs resembling each other are: a. Ascaris lumbricoides and Trichostrongylus spp. b. Diphyllobothrium latum and Paragonimus westermani c. Fasciola buski and Opisthorchis sinensis d. Hymenolepis nana and Taenia solium

5. The infective form in the Fasciola hepatica life cycle is the: a. Redia b. Metacercaria Multiple Choice Questions - Chapter 4

c. Cercaria d. Sporocyst

6. Two trematode eggs that resemble each other are: a. Fasciola hepatica and Fasciolepsis buski b. Schistosoma japonicum and Heterophyes heterophyes c. Paragonimus westermani and Clonorchis sinensis d. Schistosoma haematobium and Schistosoma mansoni

7. All of the following Digenea infections are acquired by ingesting dormant larval forms EXCEPT: a. Clonorchis sinensis b. Heterophyes heterophyes c. Paragonimus westermani d. Schistosoma haematobium

8. A large egg (180 µm x 80 µm) with a pointed lateral spine was recovered in feces from an immigrant of the West Indies. A likely parasitic infection would be: a. Clonorchis sinensis b. Fasciola hepatica c. Schistosoma japonicum d. Schistosoma mansoni

9. The immature schistosome found in human tissue is called the: a. Cercaria b. Miracidium c. Redia d. Schistosomule

Multiple Choice Questions - Chapter 4

10. An Asian patient with intestinal obstruction, mucoid diarrhea, and eosinophilia was tested for fecal parasites. The fecal sediment revealed a large (180 µm x 90 µm) oval egg with a small operculum. This parasite probably is: a. Clonorchis sinensis b. Fasciolopsis buski c. Fasciola hepatica d. Paragonimus westermani

11. Name the parasite shown in the following image:

a. Clonorchis sinensis b. Diphyllobothrium latum c. Fasciola hepatica d. Paragonimus westermani 12. Name the parasite shown in the following image:

a. Clonorchis sinensis b. Schistosoma haematobium c. Schistosoma japonicum d. Schistosoma mansoni

Multiple Choice Questions - Chapter 4

Answer Key for Chapter 4. Digenea

1. If a U.S. citizen never leaves the United States, which of the following is the only disease that he or she could acquire? a. Clonorchis sinensis b. Fasciolopsis buski c. Fasciola hepatica d. Paragonimus westermani ANS: C RATIONALE: Fasciola hepatica is found worldwide in sheep-raising areas. All the other parasites are found in the Far East. P. westermani is also found in India and parts of Africa.

KEY: Digenea: geographic distribution | Cognitive level: recall

2. The egg of one trematode species can be recovered in urine. This parasite is: a. Clonorchis sinensis b. Heterophyes heterophyes c. Schistosoma haematobium d. Schistosoma japonicum ANS: C RATIONALE: S. haematobium adults live in blood vessels near the bladder and rectum. Eggs shed in tissue may eventually appear in the bladder and then appear in the urine.

KEY: Digenea: life cycle | Cognitive level: correlation

3. For which of the following is sputum useful in the diagnosis of parasitic infection? a. Clonorchis sinensis b. Fasciola hepatica c. Paragonimus westermani d. Schistosoma mansoni ANS: C RATIONALE: The P. westermani larva exits the cyst and migrates to the lungs, where it matures to become an adult.

Multiple Choice Questions - Chapter 4

KEY: Digenea: life cycle | Cognitive level: correlation

4. Two helminth eggs resembling each other are: a. Ascaris lumbricoides and Trichostrongylus spp. b. Diphyllobothrium latum and Paragonimus westermani c. Fasciola buski and Opisthorchis sinensis d. Hymenolepis nana and Taenia solium ANS: B RATIONALE: D. latum and P. westermani are both operculated and both have terminal knobs or thickenings.

KEY: Digenea: identification | Cognitive level: correlation

5. The infective form in the Fasciola hepatica life cycle is the: a. Redia b. Metacercaria c. Cercaria d. Sporocyst ANS: B RATIONALE: Metacercariae encyst on plants, crayfish, or fish, which are ingested by susceptible hosts.

KEY: Digenea: life cycle | Cognitive level: recall

6. Two trematode eggs that resemble each other are: a. Fasciola hepatica and Fasciolepsis buski b. Schistosoma japonicum and Heterophyes heterophyes c. Paragonimus westermani and Clonorchis sinensis d. Schistosoma haematobium and Schistosoma mansoni ANS: A RATIONALE: Fasciola hepatica and Fasciolopsis buski eggs cannot be differentiated visually, so species differentiation relies on symptoms, travel history, and recovery of an adult organism.

KEY: Digenea: identification | Cognitive level: correlation Multiple Choice Questions - Chapter 4

7. All of the following Digenea infections are acquired by ingesting dormant larval forms EXCEPT: a. Clonorchis sinensis b. Heterophyes heterophyes c. Paragonimus westermani d. Schistosoma haematobium ANS: D RATIONALE: Schistosoma haematobium infection occurs when cercariae penetrate broken skin, lose their tails, and migrate to blood vessels around the bladder.

KEY: Digenea: life cycle | Cognitive level: correlation

8. A large egg (180 µm x 80 µm) with a pointed lateral spine was recovered in feces from an immigrant of the West Indies. A likely parasitic infection would be: a. Clonorchis sinensis b. Fasciola hepatica c. Schistosoma japonicum d. Schistosoma mansoni ANS: D RATIONALE: Eggs of Schistosoma spp. are not operculated as are the other Digenea parasites.

Also, the distinctive lateral spine further confirms the identification.

KEY: Digenea: identification | Cognitive level: recall

9. The immature schistosome found in human tissue is called the: a. Cercaria b. Miracidium c. Redia d. Schistosomule ANS: D RATIONALE: Cercariae penetrate skin and then lose their tails to become a schistosomule before moving through the blood vessel to the final maturation site.

Multiple Choice Questions - Chapter 4

KEY: Digenea: life cycle | Cognitive level: correlation

10. An Asian patient with intestinal obstruction, mucoid diarrhea, and eosinophilia was tested for fecal parasites. The fecal sediment revealed a large (180 µm x 90 µm) oval egg with a small operculum. This parasite probably is: a. Clonorchis sinensis b. Fasciolopsis buski c. Fasciola hepatica d. Paragonimus westermani ANS: B RATIONALE: Travel history or country of origin and clinical symptoms are important when differentiating trematode species, especially F. buski and F. hepatica. F. buski is found in Asia and invades the patient’s GI tract, causing intestinal tract disease; F. hepatica (found worldwide) invades the liver, causing hepatic symptoms.

KEY: Digenea: geographic distribution/identification | Cognitive level: correlation 11. Name the parasite shown in the following image: a. Clonorchis sinensis b. Diphyllobothrium latum c. Fasciola hepatica d. Paragonimus westermani ANS: C RATIONALE: This view is of the egg of Fasciola hepatica. This large egg is not easily differentiated from that of Fasciolopsis buski. The final determination relies on geographic distribution, travel history, or recovery of the adult.

KEY: Protozoa: parasite identification | Cognitive level: recall/correlation

12. Name the parasite shown in the following image: a. Clonorchis sinensis b. Schistosoma haematobium c. Schistosoma japonicum d. Schistosoma mansoni ANS: B Multiple Choice Questions - Chapter 4

RATIONALE: This view is of the egg of Schistosoma haematobium. The differentiating characteristic is the presence of the terminal spine visible in the lower right position in this image.

KEY: Protozoa: parasite identification | Cognitive level: recall/correlation

Multiple Choice Questions - Chapter 4

Chapter 5. Protozoa: Amoeba

1. An Entamoeba histolytica trophozoite may be identified by which of the following morphologic features? a. Ingested RBCs and a single nucleus with a central karyosome b. Ingested RBCs and a single nucleus with an eccentric karyosome c. Ingested RBCs, a single nucleus, and a large cytoplasmic glycogen vacuole d. Ingested WBCs and two nucleoli with central karyosomes

2. Entamoeba histolytica can be differentiated from E. dispar based on differences in the: a. Size of the cyst b. Number of nuclei in the cyst c. Location of the karyosome d. None of these. The organisms cannot be differentiated morphologically.

3. Entamoeba histolytica can be differentiated from E. hartmani based on differences in the: a. Size of the cyst b. Number of nuclei in the cyst c. Location of the karyosome d. None of these. The organisms cannot be differentiated morphologically.

4. The most prominent morphologic feature used to identify Iodamoeba bütschlii is: a. A large glycogen mass b. Four nuclei with large karyosomes c. Ingested bacteria d. Pointed chromatoidal bars

5. Drainage from an oral gum lesion revealed the presence of a possible amoeba. An amoeba with a single nucleus and ingested WBCs was noted in a trichrome-stained preparation of the drainage material. Which of the following is the probable parasite found in this sample? a. Entamoeba histolytica/dispar Multiple Choice Questions - Chapter 5

b. Entamoeba gingivalis c. Entamoeba polecki d. Trichomonas tenax

6. A permanently stained fecal smear revealed several cysts containing eight nucleoli that had clumped chromatin and eccentrically located karyosomes. The likely identity of this parasite is: a. Dientamoeba fragilis b. Endolimax nana c. Entamoeba coli d. Entamoeba histolytica

7. A 10-year-old boy with symptoms of meningitis and a history of swimming in his farm pond was brought to the hospital emergency department. Examination of his CSF revealed motile amoeba measuring 12 µm in diameter. The most likely parasite is: a. Acanthamoeba spp. trophozoites b. Dientamoeba fragilis trophozoites c. Endolimax nana trophozoites d. Naeglaria fowleri trophozoites

8. The parasite most often associated with contaminated contact lens cleaning solution is: a. Acanthamoeba spp. b. Dientamoeba fragilis trophozoites c. Endolimax nana trophozoites d. Naeglaria fowleri trophozoites

9. A cyst measuring 25 µm in diameter was observed in a fecal smear. It contained a large, clear central vacuole with four homogeneous nuclei lying outside the vacuole near the cyst wall. This parasitic form suggests the presence of: a. Blastocystis hominis b. Endolimax nana c. Iodamoeba bütschlii d. Trichomonas tenax Multiple Choice Questions - Chapter 5

10. The free-living amoeba associated with meningitis is: a. Dientamoeba fragilis b. Entamoeba coli c. Entamoeba histolytica d. Naegleria fowleri

11. Name the parasite shown in the following image:

a. Entamoeba coli b. Entamoeba dispar c. Entamoeba hartmanni d. Entamoeba histolytica 12. Name the parasite shown in the following image:

a. Dientamoeba fragilis b. Entamoeba coli c. Entamoeba hartmanni d. Iodamoeba bütschlii

Multiple Choice Questions - Chapter 5

Answer Key for Chapter 5. Protozoa: Amoeba

1. An Entamoeba histolytica trophozoite may be identified by which of the following morphologic features? a. Ingested RBCs and a single nucleus with a central karyosome b. Ingested RBCs and a single nucleus with an eccentric karyosome c. Ingested RBCs, a single nucleus, and a large cytoplasmic glycogen vacuole d. Ingested WBCs and two nucleoli with central karyosomes ANS: A RATIONALE: Entamoeba histolytica trophozoites have a centrally located karyosome with evenly spaced chromatin in the single nucleus and ingested RBCs. KEY: Protozoa: morphology | Cognitive level: correlation

2. Entamoeba histolytica can be differentiated from E. dispar based on differences in the: a. Size of the cyst b. Number of nuclei in the cyst c. Location of the karyosome d. None of these. The organisms cannot be differentiated morphologically.

ANS: D RATIONALE: E. histolytica and E. dispar cannot be differentiated morphologically unless ingested RBCs are visible in E. histolytica.

KEY: Protozoa: morphology | Cognitive level: correlation

3. Entamoeba histolytica can be differentiated from E. hartmanni based on differences in the: a. Size of the cyst b. Number of nuclei in the cyst c. Location of the karyosome d. None of these. The organisms cannot be differentiated morphologically.

ANS: A RATIONALE: E. histolytica and E. hartmanni are differentiated by size: E. histolytica (10 to 20 µm) and E. hartmanni (< 10 µm); E. histolytica also ingests RBCs. Multiple Choice Questions - Chapter 5

KEY: Protozoa: morphology | Cognitive level: correlation

4. The most prominent morphologic feature used to identify Iodamoeba bütschlii is: a. A large glycogen mass b. Four nuclei with large karyosomes c. Ingested bacteria d. Pointed chromatoidal bars ANS: A RATIONALE: A single large glycogen vacuole is a characteristic finding when attempting to identify I. bütschlii.

KEY: Protozoa: morphology | Cognitive level: recall

5. Drainage from an oral gum lesion revealed the presence of a possible amoeba. An amoeba with a single nucleus and ingested WBCs was noted in a trichrome-stained preparation of the drainage material. Which of the following is the probable parasite found in this sample? a. Entamoeba histolytica/dispar b. Entamoeba gingivalis c. Entamoeba polecki d. Trichomonas tenax ANS: B RATIONALE: KEY: Protozoa: morphology | Cognitive level: correlation

6. A permanently stained fecal smear revealed several cysts containing eight nucleoli that had clumped chromatin and eccentrically located karyosomes. The likely identity of this parasite is: a. Dientamoeba fragilis b. Endolimax nana c. Entamoeba coli d. Entamoeba histolytica ANS: B

Multiple Choice Questions - Chapter 5

RATIONALE: The E. coli cyst usually contains five to eight nuclei, whereas E. histolytica’s cyst will have up to four nuclei. Other parasitic cysts often have only one or two nuclei, and never more than four.

KEY: Protozoa: morphology | Cognitive level: recall

7. A 10-year-old boy with symptoms of meningitis and a history of swimming in his farm pond was brought to the hospital emergency department. Examination of his CSF revealed motile amoeba measuring 12 µm in diameter. The most likely parasite is: a. Acanthamoeba spp. trophozoites b. Dientamoeba fragilis trophozoites c. Endolimax nana trophozoites d. Naeglaria fowleri trophozoites ANS: D RATIONALE: N. fowleri lives in warm water ponds and usually enters the host through the mucous membranes of the nose and migrates to the CNS. Acanthamoeba spp. rarely enters the CNS. The other two parasites do not invade the CNS. KEY: Protozoa: life cycle/epidemiology | Cognitive level: correlation

8. The parasite most often associated with contaminated contact lens cleaning solution is: a. Acanthamoeba spp. b. Dientamoeba fragilis trophozoites c. Endolimax nana trophozoites d. Naeglaria fowleri trophozoites ANS: A RATIONALE: Acanthamoeba spp. causes corneal keratitis and comes in contact with eyes through contaminated eye-care solutions. N. fowleri is usually associated with CNS infections.

KEY: Protozoa: life cycle/epidemiology | Cognitive level: correlation

9. A cyst measuring 25 µm in diameter was observed in a fecal smear. It contained a large, clear central vacuole with four homogeneous nuclei lying outside the vacuole near the cyst wall. This parasitic form suggests the presence of: a. Blastocystis hominis Multiple Choice Questions - Chapter 5

b. Endolimax nana c. Iodamoeba bütschlii d. Trichomonas tenax ANS: A RATIONALE: B. hominis protozoa are identified using the trichrome stain. The organism is round and varies greatly in size from 6 to 40 μm in diameter. The central area of the cell resembles a large vacuole surrounded by several small, dark-staining nuclei.

KEY: Protozoa: parasite identification | Cognitive level: recall/correlation

10. The free-living amoeba associated with meningitis is: a. Dientamoeba fragilis b. Entamoeba coli c. Entamoeba histolytica d. Naegleria fowleri ANS: D RATIONALE: N. fowleri is found in warm pond water. Humans come in contact with this parasite while swimming in the water.

KEY: Protozoa: life cycle/epidemiology | Cognitive level: correlation

11. Name the parasite shown in the following image: a. Entamoeba coli b. Entamoeba dispar c. Entamoeba hartmanni d. Entamoeba histolytica ANS: D RATIONALE: This view is of the amoeba Entamoeba histolytica. The differentiating characteristic is the presence of engulfed RBCs. E. dispar is a nonpathogenic race of E. histolytica and never ingests RBCs. E. hartmanni is a smaller nonpathogenic race of the species.

E. coli is differentiated by its distinctly different nuclear structure.

KEY: Protozoa: parasite identification | Cognitive level: recall/correlation

12. Name the parasite shown in the following image: Multiple Choice Questions - Chapter 5

a. Dientamoeba fragilis b. Entamoeba coli c. Entamoeba hartmanni d. Iodamoeba bütschlii ANS: A RATIONALE: This view is of the amoeba Dientamoeba fragilis. The differentiating characteristic is the presence of two nuclei in this trophozoite form. All of the other choices have only one nucleus in the trophozoite form.

KEY: Protozoa: parasite identification | Cognitive level: recall/correlation

Multiple Choice Questions - Chapter 5

Chapter 6. Protozoa: Flagellates and Ciliates

1. Which of the following parasitic organisms is considered to be a sexually transmitted disease? a. Blastocystis hominis b. Dientamoeba fragilis c. Entamoeba gingivalis d. Trichomonas vaginalis

2. Name the parasite shown in the following image:

a. Chilomastix mesnili b. Enteromonas hominis c. Giardia lamblia d. Trichomonas vaginalis

3. Which of the following parasites was formerly thought to have no known cyst phase in its life cycle? a. Chilomastix mesnili b. Dientamoeba fragilis c. Enteromonas spp. d. Giardia lamblia

4. The most appropriate sample type and collection schedule for diagnosing Giardia lamblia is: a. One stool specimen b. Two stool specimens c. Three or more specimens collected on separate days d. Only one diarrheic stool specimen is needed.

Multiple Choice Questions - Chapter 6

5. Giardia intestinalis infection is acquired by: a. Ingesting contaminated food or water b. Swimming in fecally contaminated water c. Walking barefoot in contaminated soil d. Either a or b

6. The structure that is always visible in stained preparations of Balantidium coli trophozoites and cysts is: a. Cilia b. Ingested bacteria c. Macronucleus d. Micronucleus

7. Name the parasite shown in the following image:

a. Chilomastix mesnili b. Enteromonas hominis c. Giardia lamblia d. Trichomonas vaginalis

Multiple Choice Questions - Chapter 6

Answer Key for Chapter 6. Protozoa: Flagellates and Ciliates

1. Which of the following parasitic organisms is considered to be a sexually transmitted disease? a. Blastocystis hominis b. Dientamoeba fragilis c. Entamoeba gingivalis d. Trichomonas vaginalis ANS: D RATIONALE: T. vaginalis is a well-documented STD. KEY: Flagellates: life cycle/epidemiology | Cognitive level: recall

2. Name the parasite shown in the following image: a. Chilomastix mesnili b. Enteromonas hominis c. Giardia lamblia d. Trichomonas vaginalis ANS: C RATIONALE: This view is of the flagellate Giardia lamblia. The other parasites are identified by size, shape, nuclear characteristics, and the location in the host.

KEY: Flagellates: parasite identification | Cognitive level: recall

3. Which of the following parasites was formerly thought to have no known cyst phase in its life cycle? a. Chilomastix mesnili b. Dientamoeba fragilis c. Enteromonas spp. d. Giardia lamblia ANS: B RATIONALE: D. fragilis has been characterized as being the only protozoan parasite to have no known cyst, but now it has a documented, but rarely seen, cyst. Because all other trophozoites

Multiple Choice Questions - Chapter 6

have only one nucleus, care must be taken to not confuse the D. fragilis trophozoite with another parasitic cyst.

KEY: Protozoa: morphology | Cognitive level: recall

4. The most appropriate sample type and collection schedule for diagnosing Giardia lamblia is: a. One stool specimen b. Two stool specimens c. Three or more specimens collected on separate days d. Only one diarrheic stool specimen is needed.

ANS: C RATIONALE: G. lamblia (G. intestinalis) attaches to the intestinal lining of the host via its sucking disk. Due to this attachment, parasites are shed intermittently, so it is necessary to collect multiple specimens if this parasite is suspected and not recovered in early collections.

KEY: Protozoa: diagnosis | Cognitive level: correlation

5. Giardia intestinalis infection is acquired by: a. Ingesting contaminated food or water b. Swimming in fecally contaminated water c. . Walking barefoot in contaminated soil d Either a or b

ANS: D RATIONALE: G. lamblia (G. intestinalis) infections are acquired by ingesting cysts from any contaminated food or water, or by transferring cysts from contaminated surfaces. Since Giardia spp. are resistant to chlorine, infections can be acquired by swimming in swimming pools as well as contaminated pond or river waters.

KEY: Protozoa: how infection occurs | Cognitive level: correlation

6. The structure that is always visible in stained preparations of Balantidium coli trophozoites and cysts is: a. Cilia b. Ingested bacteria Multiple Choice Questions - Chapter 6

c. Macronucleus d. Micronucleus ANS: D RATIONALE: The macronucleus is always visible in stained preparations of B. coli, but any or all of the other choices may be visible in any preparation.

KEY: Protozoa: parasite identification | Cognitive level: correlation

7. Name the parasite shown in the following image: a. Chilomastix mesnili b. Enteromonas hominis c. Giardia lamblia d. Trichomonas vaginalis ANS: D RATIONALE: This view is of the flagellate Trichomonas vaginalis. T. vaginalis appears slightly larger than leukocytes, and the whipping motion of the flagella is clearly visible in fresh, unstained urine. The other parasites are identified by size, shape, nuclear characteristics, and the location in the host.

KEY: Flagellates: parasite identification | Cognitive level: recall

Multiple Choice Questions - Chapter 6

Chapter 7. Protozoa: The Hemoflagellates Trypanosoma spp. and Leishmania spp.

1. Visceral leishmaniasis is caused by: a. Trypanosoma brucei gambience b. Trypanosoma cruzi c. Leishmania braziliensis d. Leishmania donovani

2. Which of the following parasites can be transmitted via blood transfusions? a. Trypanosoma brucei gambience b. Trypanosoma cruzi c. Leishmania braziliensis d. Leishmania donovani

3. Name the parasite shown in the following image:

a. Plasmodium falciparum b. Trypanosoma brucei rhodiense c. Trypanosoma brucei gambiense d. Trypanosoma cruzi

4. A forty-year-old immigrant from Bangladesh presented with splenomegaly and hepatomegaly. When questioned, the patient stated that he had diarrhea, dysentery, and weight loss a year or so ago, before coming to the United States. Since that time, he had become easily fatigued and felt weak. These symptoms suggest prior infection with which of the following parasites? a. Trypanosoma brucei gambience b. Trypanosoma cruzi Multiple Choice Questions - Chapter

c. Leishmania braziliensis d. Leishmania donovani

5. A traveler returning from a trip to the Andes Mountains in Central America noticed the formation of a boil on his lower leg. His physician opened the lesion and sent the purulent material to the lab for analysis. A stained preparation of the submitted material is shown here.

Name the parasitic form seen in this view:

a. Amastigote form b. Leptomastigote form c. Promastigote form d. Trypomastigote form

Multiple Choice Questions - Chapter

Answer Key for Chapter 5. Protozoa: The Hemoflagellates Trypanosoma spp. and Leishmania spp.

1. Visceral leishmaniasis is caused by: a. Trypanosoma brucei gambience b. Trypanosoma cruzi c. Leishmania braziliensis d. Leishmania donovani ANS: D RATIONALE: L. donovani invades internal organs, causing visceral leishmaniasis. The other Leishmania species cause diffuse cutaneous leishmaniasis.

KEY: Kinetoplastida: pathology | Cognitive level: correlation

2. Which of the following parasites can be transmitted via blood transfusions? a. Trypanosoma brucei gambience b. Trypanosoma cruzi c. Leishmania braziliensis d. Leishmania donovani ANS: B RATIONALE: When trypomastigotes of Trypanosoma cruzi are present in blood, they are infective and can cause disease in transfusion recipients.

KEY: Kinetoplastida: life cycle | Cognitive level: correlation

3. Name the parasite shown in the following image: a. Plasmodium falciparum b. Trypanosoma brucei rhodiense c. Trypanosoma brucei gambiense d. Trypanosoma cruzi ANS: D RATIONALE: This view shows a Trypanosoma cruzi trypanosome form in the blood. This parasite is differentiated by its sharply curved appearance. Additional information concerning the geographic origin of the patient is helpful when identifying this organism.

Multiple Choice Questions - Chapter

KEY: Kinetoplastida: parasite identification | Cognitive level: recall

4. A forty-year-old immigrant from Bangladesh presented with splenomegaly and hepatomegaly. When questioned, the patient stated that he had diarrhea, dysentery, and weight loss a year or so ago, before coming to the United States. Since that time, he had become easily fatigued and felt weak. These symptoms suggest prior infection with which of the following parasites? a. Trypanosoma brucei gambience b. Trypanosoma cruzi c. Leishmania braziliensis d. Leishmania donovani ANS: D RATIONALE: L. donovani invades internal organs, causing visceral leishmaniasis. The other Leishmania species cause diffuse cutaneous leishmaniasis. LD bodies are found in infected organ tissues. Biopsies of this patient’s enlarged organs would confirm the diagnosis.

KEY: Kinetoplastida: pathology | Cognitive level: correlation

5. A traveler returning from a trip to the Andes Mountains in Central America noticed the formation of a boil on his lower leg. His physician opened the lesion and sent the purulent material to the lab for analysis. A stained preparation of the submitted material is shown here.

Name the parasitic form seen in this view: a. Amastigote form b. Leptomastigote form c. Promastigote form d. Trypomastigote form ANS: A RATIONALE: The amastigote form is found in the primary local lesions of the skin for all Leishmannia spp. For L. Donovani, amastigote forms invade internal organs, causing visceral leishmaniasis. The other Leishmania species cause diffuse cutaneous leishmaniasis. LD bodies are found in infected organ tissues. Biopsies of this patient’s enlarged organs would confirm the diagnosis. The promastigote form is found in the sandfly vector. The trypanosome form is found in the blood stream for T. cruzi, with amastigote forms found in tissue macrophages.

KEY: Kinetoplastida: pathology | Cognitive level: correlation

Multiple Choice Questions - Chapter

Chapter 8. Protozoa: Sporozoa

1. Which of the following parasites is able to cause nosocomial infections if “enteric precautions” are not maintained for patients with severe diarrhea? a. Cryptosporidium parvum b. Enterobius vermicularis c. Giardia lamblia d. Cystoisospora belli

2. An AIDS patient suffering with chronic diarrhea was tested for intestinal parasites. Among the testing procedures was an acid-fast stain on a direct fecal smear. The smear revealed redstained, round structures measuring 4 µm in diameter. The most likely parasite is: a. Blastocystis hominis b. Cryptosporidium parvum c. Cyclospora spp. d. Microsporidia

3. Local city water supplies have been sources of parasitic infections. The most common organisms implicated in these events include: a. Cryptosporidium parvum and Giardia lamblia b. Diphyllobothrium fragilis and Entamoeba histolytica c. Giardia lamblia and Cystoisospora belli d. Cystoisospora belli and Entamoeba histolytica

4. Outbreaks of diarrhea have been caused by a parasite that has been associated with raspberries, strawberries, herbs, and baby lettuces. The most likely parasite is: a. Cryptosporidium parvum b. Cyclospora cayetanensis c. Giardia lamblia d. Cystoisospora belli

Multiple Choice Questions - Chapter 8

5. A fecal smear was stained using acid-fast reagents. Examination of the smear revealed round, red forms measuring 8 to 10 µm in diameter. The most likely parasite is: a. Microsporidium spp. b. Cystoisospora belli c. Cyclospora spp. d. Cryptosporidium parvum

6. The malaria parasite species characterized by a single ameboid trophozoite and surrounded by red-stained Schüffner’s dots is: a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax

7. The malaria parasite species characterized by a crescent-shaped gametocyte is: a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax

8. The malaria parasite species characterized by a schizont containing 8 to 12 merozoites is: a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax

9. Massive hemolysis leading to blackwater fever is a characteristic clinical finding for which of the following parasites? a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale Multiple Choice Questions - Chapter 8

d. Plasmodium vivax

10. Plasmodium vivax and Plasmodium ovale are similar for all of the following EXCEPT both: a. Can cause true relapses b. Have Schüffner’s dots c. Preferentially invade reticulocytes d. Have only single-ring forms

11. Babesia spp. infections may be confused with which other parasite? a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax

12. Which of the sporozoa is considered to be indigenous to the United States? a. Babesia microti b. Plasmodium falciparum c. Plasmodium malariae d. Plasmodium vivax

13. The infective stage for Toxoplasma gondii in humans is the: a. Merozoite b. Öocyst c. Sarcocyst d. Sporozoite

14. Name the parasite shown in the following image:

Multiple Choice Questions - Chapter 8

a. b. c. d.

Babesia microti Plasmodium falciparum Plasmodium malariae Plasmodium vivax

15. Name the parasite shown in the following image:

a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax

16. Name the parasite shown in the following image:

a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale Multiple Choice Questions - Chapter 8

d. Plasmodium vivax

Multiple Choice Questions - Chapter 8

Answer Key for Chapter 8. Protozoa: Sporozoa

1. Which of the following parasites is able to cause nosocomial infections if “enteric precautions” are not maintained for patients with severe diarrhea? a. Cryptosporidium parvum b. Enterobius vermicularis c. Giardia lamblia d. Cystoisospora belli ANS: A RATIONALE: C. parvum öocysts are immediately infective when passed, whereas those of I. belli are not.

KEY: Protozoa: life cycle/pathology | Cognitive level: correlation

2. An AIDS patient suffering with chronic diarrhea was tested for intestinal parasites. Among the testing procedures was an acid-fast stain on a direct fecal smear. The smear revealed redstained, round structures measuring 4 µm in diameter. The most likely parasite is: a. Blastocystis hominis b. Cryptosporidium parvum c. Cyclospora spp. d. Microsporidia ANS: B RATIONALE: An acid-fast stain is used to stain C. parvum. This parasite is often characterized by its size. Note: Cyclospora spp. are 8 to 10 µm in size and microsporidia are 1 µm in size.

KEY: Protozoa: morphology/ID techniques | Cognitive level: correlation

3. Local city water supplies have been sources of parasitic infections. The most common organisms implicated in these events include: a. Cryptosporidium parvum and Giardia lamblia b. Diphyllobothrium fragilis and Entamoeba histolytica c. Giardia lamblia and Cystoisospora (Isospora) belli d. Cystoisospora belli and Entamoeba histolytica

Multiple Choice Questions - Chapter 8

ANS: A RATIONALE: C. parvum and G. lamblia have caused several waterborne infections.

KEY: Protozoa: life cycle/epidemiology | Cognitive level: correlation

4. Outbreaks of diarrhea have been caused by a parasite that has been associated with raspberries, strawberries, herbs, and baby lettuces. The most likely parasite is: a. Cryptosporidium parvum b. Cyclospora cayetanensis c. Giardia lamblia d. Cystoisospora belli ANS: B RATIONALE: Diarrheal outbreaks of Cyclospora cayetanensis have been associated with improperly washed berries and mesclun lettuces.

KEY: Protozoa: life cycle/epidemiology | Cognitive level: correlation

5. A fecal smear was stained using acid-fast reagents. Examination of the smear revealed round, red forms measuring 8 to 10 µm in diameter. The most likely parasite is: a. Microsporidium spp. b. Cystoisospora belli c. Cyclospora spp. d. Cryptosporidium parvum ANS: C RATIONALE: Acid-fast stain is used to stain Cyclospora spp., which are 8 to 10 µm in size.

Note: C. parvum is 4 µm, I. belli is 30 µm x 12 µm, and microsporidia are 1 µm in size.

KEY: Sporozoa: identification | Cognitive level: recall

6. The malaria parasite species characterized by a single ameboid trophozoite and surrounded by red-stained Schüffner’s dots is: a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax Multiple Choice Questions - Chapter 8

ANS: D RATIONALE: Plasmodium vivax infections are characterized by a single ameboid trophozoite that is surrounded by red-stained Schüffner’s dots. Other characteristic findings include a schizont containing 12 to 24 merozoites and a round gametocyte.

KEY: Sporozoa: malaria identification | Cognitive level: recall

7. The malaria parasite species characterized by a crescent-shaped gametocyte is: a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax ANS: A RATIONALE: Plasmodium falciparum infections are characterized by the appearance of a crescent-shaped gametocyte in the RBC. Other characteristic findings include the presence of multiple small-ring trophozoites in a single red cell.

KEY: Sporozoa: malaria identification | Cognitive level: recall

8. The malaria parasite species characterized by a schizont containing 8 to 12 merozoites is: a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax ANS: B RATIONALE: Plasmodium malariae infections are characterized by the appearance of a schizont containing 8 to 12 merozoites in the RBC. Other characteristic findings include a singlering trophozoite without Schüffner’s dots and an ovoid gametocyte.

KEY: Sporozoa: malaria identification | Cognitive level: recall

9. Massive hemolysis leading to blackwater fever is a characteristic clinical finding for which of the following parasites? a. Plasmodium falciparum Multiple Choice Questions - Chapter 8

b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax ANS: A RATIONALE: Plasmodium falciparum causes blackwater fever by causing the massive destruction of red blood cells. The elimination of massive amounts of hemoglobin leads to darkcolored (blackwater) urine and renal failure. CNS symptoms occur when RBCs clump and block capillaries in the brain.

KEY: Sporozoa: malaria pathology | Cognitive level: correlation

10. Plasmodium vivax and Plasmodium ovale are similar for all of the following EXCEPT both: a. Can cause true relapses b. Have Schüffner’s dots c. Preferentially invade reticulocytes d. Have only single-ring forms ANS: C RATIONALE: Only P. vivax invades reticulocytes; therefore, using a reticulocyte counterstain may aid identification of this parasite.

KEY: Sporozoa: malaria identification | Cognitive level: correlation

11. Babesia spp. infections may be confused with which other parasite? a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax ANS: A RATIONALE: Explain Plasmodium falciparum first. The technologist may erroneously suspect P. falciparum as the infective agent when observing Babesia spp. in RBCs because both parasites often have two-ring trophozoite forms in a single red blood cell.

KEY: Sporozoa: parasitic identification | Cognitive level: recall

Multiple Choice Questions - Chapter 8

12. Which of the sporozoa is considered to be indigenous to the United States? a. Babesia microti b. Plasmodium falciparum c. Plasmodium malariae d. Plasmodium vivax ANS: A RATIONALE: Babesia spp. are found in the northeastern United States and California. P. vivax has been endemic in the United States, but it was eliminated through vector control.

KEY: Sporozoa: epidemiology | Cognitive level: recall

13. The infective stage for Toxoplasma gondii in humans is the: a. Merozoite b. Öocyst c. Sarcocyst d. Sporozoite ANS: B RATIONALE: The öocyst contains sporozoites that upon ingestion are released from the öocyst and invade intestinal epithelium. Merozoites are associated with Plasmodium spp. Infections, and sarcocysts are the infective agent for Sarcocystis spp. infections.

KEY: Protozoa: life cycle | Cognitive level: recall

14. Name the parasite shown in the following image: a. Babesia microti b. Plasmodium falciparum c. Plasmodium malariae d. Plasmodium vivax ANS: A RATIONALE: This view is of trophozoites of Babesia microti. This parasite may be confused with Plasmodium falciparum because this parasite often has multiple-ring trophozoites in a single RBC. KEY: Sporozoa: parasite identification | Cognitive level: recall

Multiple Choice Questions - Chapter 8

15. Name the parasite shown in the following image: a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax

ANS: D RATIONALE: This view is of the trophozoite form of Plasmodium vivax. Note the characteristic red Schüffner’s dots.

KEY: Protozoa: parasite identification | Cognitive level: recall/correlation

16. Name the parasite shown in the following image: a. Plasmodium falciparum b. Plasmodium malariae c. Plasmodium ovale d. Plasmodium vivax ANS: A RATIONALE: This view is the gametocyte form of Plasmodium falciparum. Note the characteristic crescent/banana shape of this form.

KEY: Protozoa: parasite identification | Cognitive level: recall/correlation

Multiple Choice Questions - Chapter 8

Chapter 9. Arthropoda

1. All the following developmental stages are found in the incomplete metamorphosis life cycle of insects EXCEPT: a. Egg b. Imago c. Pupa d. Nymph

2. All the following insects develop through complete metamorphosis EXCEPT: a. Arachnids b. Fleas c. Flies d. Mosquitoes

3. The Ixodes spp. tick serves as a vector for all the following diseases EXCEPT: a. Babesia spp. b. Borrelia burgdorferi c. Franciella tularensis d. Rickettsia rickettsii

4. Evidence of pediculosis infestation includes the finding of: a. Louse antibodies in patient serum b. Eggs attached to hair shafts c. Larvae recovered from patient clothing d. A tunnel of insects in the skin

5. Which of the following Arthropoda is involved in the transmission of African sleeping sickness? a. Bug Multiple Choice Questions - Chapter 9

b. Flea c. Fly d. Mosquito

6. Which of the following Arthropoda is involved in the transmission of the Black plague? a. Flea b. Fly c. Mosquito d. Tick

7. Which of the following Arthropoda is involved in the transmission of Rocky Mountain spotted fever? a. Bug b. Fly c. Mosquito d. Tick

8. If a parasite can be transferred from an adult insect to its offspring, it is said to be transferred: a. Incidentally b. Mechanically c. Sexually d. Vertically

9. The life cycle of Sarcoptes scabiei differs from other Arthropoda because it: a. Feeds only on blood b. Has only four legs c. Is a permanent ectoparasite d. Can transfer viral particles to the host

10. Transmission of Leishmania spp. to humans is associated with: Multiple Choice Questions - Chapter 9

a. Culex spp. b. Phlebotomus spp. c. Simulium spp. d. Tabanus spp.

11. Rickettsia typhi is transmitted by: a. Dermacentor spp. b. Pediculus spp. c. Sarcoptes scabiei d. Xenopsylla cheopis

12. Francisella tularensis (tularemia) is transmitted by: a. Amblyomma americanum b. Dermacentor spp. c. Ixodes spp. d. Ornithodoros spp.

13. Name the arthropod shown in the following image:

a. Amblyomma americanum b. Dermacentor andersoni c. Ixodes spp. d. Ornithodoros spp.

14. Name the arthropod shown in the following image: Multiple Choice Questions - Chapter 9

a. Cimex lectularius b. Pediculus humanus capitis c. Pediculus humanus humanus d. Phthirus pubis

Multiple Choice Questions - Chapter 9

Answer Key for Chapter 6. Arthropoda

1. All the following developmental stages are found in the incomplete metamorphosis life cycle of insects EXCEPT: a. Egg b. Imago c. Pupa d. Nymph ANS: C RATIONALE: The pupa stage is found in the complete metamorphosis insect life cycle.

KEY: Arthropoda: life cycle | Cognitive level: recall

2. All the following insects develop through complete metamorphosis EXCEPT: a. Arachnids b. Fleas c. Flies d. Mosquitoes ANS: A RATIONALE: Arachnids, lice, true bugs, and crustaceans all develop through incomplete metamorphosis.

KEY: Arthropoda: life cycle | Cognitive level: recall

3. The Ixodes spp. tick serves as a vector for all the following diseases EXCEPT: a. Babesia spp. b. Borrelia burgdorferi c. Franciella tularensis d. Rickettsia rickettsii ANS: C RATIONALE: F. tularensis, the causative agent of tularemia, is transferred to humans via Dermacentor spp. ticks.

KEY: Arthropoda: vector disease transmission | Cognitive level: recall Multiple Choice Questions - Chapter 9

4. Evidence of pediculosis infestation includes the finding of: a. Louse antibodies in patient serum b. Eggs attached to hair shafts c. Larvae recovered from patient clothing d. A tunnel of insects in the skin ANS: B RATIONALE: Louse eggs (nits) are found attached to any body hair (location depends on species). Adult lice may also be recovered at the same time. Tunneling insects include mites such as Sarcoptes scabiei, which burrow into outer skin layers.

KEY: Arthropoda: ectoparasitic infestation | Cognitive level: correlation

5. Which of the following Arthropoda is involved in the transmission of African sleeping sickness? a. Bug b. Flea c. Fly d. Mosquito ANS: C RATIONALE: The Glossina spp. (tsetse) fly is the vector for African trypanosomiasis. All flies can act as mechanical transfer vectors for many protozoan species.

KEY: Arthropoda: vectors/life cycles | Cognitive level: recall

6. Which of the following Arthropoda is involved in the transmission of the Black plague? a. Flea b. Fly c. Mosquito d. Tick ANS: B

Multiple Choice Questions - Chapter 9

RATIONALE: The rat flea, Xenopsylla spp., is known to carry and transmit Yersinia pestis, the causative agent of bubonic plague, as well as Rickettsia mooseri and tapeworm eggs (H. nana and H. diminuta).

KEY: Arthropoda: vectors/life cycles | Cognitive level: recall

7. Which of the following Arthropoda is involved in the transmission of Rocky Mountain spotted fever? a. Bug b. Fly c. Mosquito d. Tick ANS: D RATIONALE: Dermacentor spp. hard ticks are known to carry and transmit Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever.

KEY: Arthropoda: vectors/life cycles | Cognitive level: recall

8. If a parasite can be transferred from an adult insect to its offspring, it is said to be transferred: a. Incidentally b. Mechanically c. Sexually d. Vertically ANS: D RATIONALE: When pathogens are passed from adult to egg (transovarial transmission), and then survive in the next insect lifecycle forms (egg, nymph, adult), it has been transmitted transstadially. This pathogen is said to be transmitted vertically from generation to generation.

Babesia microti can pass vertically in the Ixodes spp. tick.

KEY: Arthropoda: vector/biological transmission | Cognitive level: correlation

9. The life cycle of Sarcoptes scabiei differs from other Arthropoda because it: a. Feeds only on blood b. Has only four legs c. Is a permanent ectoparasite Multiple Choice Questions - Chapter 9

d. Can transfer viral particles to the host ANS: C RATIONALE: Sarcoptes scabiei, the mange mite, is a permanent ectoparasite that burrows into the skin, where it lives and reproduces.

KEY: Arthropoda: life cycle | Cognitive level: recall

10. Transmission of Leishmania spp. to humans is associated with: a. Culex spp. b. Phlebotomus spp. c. Simulium spp. d. Tabanus spp.

ANS: B RATIONALE: The sandfly, Phlebotomus spp., is the vector for Leishmania spp. Humans become infected when an infected fly bites the host, transferring the parasite to the subcutaneous layers of the skin. Culex spp. is the vector for W. bancrofti, and Simulium spp. is the vector for O. volvulus and M. ozzardi. Tabanus spp. is a vector for bacterial diseases—for example, anthrax Re.s.CO TES and Francisella tularensis as well as aTnB imAaN lK trySpEanLoLsoEm ThMis fly can mechanically transfer some protozoan parasite cysts.

KEY: Arthropoda: vectors/life cycle | Cognitive level: recall

11. Rickettsia typhi is transmitted by: a. Dermacentor spp. b. Pediculus spp. c. Sarcoptes scabiei d. Xenopsylla cheopis ANS: D RATIONALE: The rat flea, Xenopsylla cheopis, is the vector for Rickettsia typhi. Humans become infected when an infected flea bites the host and defecates near the bite site; bacteria may be rubbed into the wound when the host scratches the bite. Animals may ingest whole fleas while grooming themselves, thus ingesting the bacteria as well.

KEY: Arthropoda: vectors/life cycle | Cognitive level: recall

Multiple Choice Questions - Chapter 9

12. Francisella tularensis (tularemia) is transmitted by: a. Amblyomma americanum b. Dermacentor spp. c. Ixodes spp. d. Ornithodoros spp.

ANS: B RATIONALE: The tick Dermacentor andersoni is the vector for Francisella tularensis.

Humans become infected when an infected tick bites the host. Infected saliva is transferred to the host while the tick is feeding. Rarely, infected feces may be rubbed into the wound when the host scratches the bite site.

KEY: Arthropoda: vectors/life cycle | Cognitive level: recall

13. Name the arthropod shown in the following image: a. Amblyomma americanum b. Dermacentor andersoni c. Ixodes spp. d. Ornithodoros spp.

ANS: C RATIONALE: The tick Ixodes spp. is the vector for three pathogenic organisms: Borrelia burgdorferi (the causative agent of Lyme disease); Babesia microti (see page 119 in 7th Ed.); and the rickettsial pathogen Anaplasma phagocytophilum, the agent of “human granulocytic anaplasmosis” (HGA), formerly called Ehrlichia phagocytophilum and known as “human granulocytic ehrlichiosis” (HGE). All are transmitted to humans through the bite of Ixodes spp. ticks. Infected saliva is transferred to the host while the tick is feeding.

KEY: Arthropoda: parasite identification | Cognitive level: recall

14. Name the arthropod shown in the following image: a. Cimex lectularius b. Pediculus humanus capitis c. Pediculus humanus humanus d. Phthirus pubis ANS: D

Multiple Choice Questions - Chapter 9

RATIONALE: The tick Phthirus pubis (crab louse) is a causative agent of pediculosis. Pubic lice are usually transferred via sexual intercourse, but infections may be acquired in locker rooms from towels and from mats on gymnasium floors.

KEY: Arthropoda: parasite identification | Cognitive level: recall

Multiple Choice Questions - Chapter 9

Chapter 10. Clinical Laboratory Procedures

1. For which of the following parasites might the examination of as many as six specimens be needed in order to recover the parasite? a. Dientamoeba fragilis b. Entamoeba histolytica c. Giardia lamblia d. Strongyloides stercoralis

2. If patients must be purged to enhance recovery of parasites, any of the following enemics may be used EXCEPT: a. Castor oil b. Epsom salts c. Fleet phospho-soda d. Sodium sulfate

3. The chemical found in fecal preservatives that enhances adhesion of parasites to slides prepared for trichrome stain is: a. MIF (merthiolate-iodine-formaldehyde) b. PVA (polyvinyl-alcohol) c. SAF (sodium acetate-acetic acid-formalin) d. Schaudinn solution

4. When performing an ocular micrometer calibration procedure for the 40x objective, the technologist noted that the 40 mark on the ocular micrometer scale lined up exactly with the 0.09-mm line on the stage micrometer scale. The width in millimeters for each ocular scale division is: a. 0.09 mm b. 0.00225 mm c. 2.25 µm d. 40 µm

Multiple Choice Questions - Chapter 10

5. Charcot-Leyden crystals are occasionally observed in stool. These crystals are probably from breakdown products of: a. Eosinophils b. Lymphocytes c. Monocytes d. Neutrophils

6. The most sensitive method used to recover Acanthamoeba spp. from eye-care solutions or corneal samples is the: a. Giemsa stain b. Monoclonal antibody method c. Non-nutrient agar plate seeded with E. coli bacteria d. Novy-MacNeal-Nicolle (NNN) medium

7. Modified acid-fast stain is used to visualize several parasites including Cryptosporidium parvum. The modification that differentiates this method from that used to stain mycobacteria (AFB) is that in the parasite method: a. A counterstain is needed b. The stain is more concentrated c. The staining time is much longer d. The decolorizer is weaker

8. Artifacts found in feces that can be confused with eggs or cysts are: a. Degenerating GI tract-lining cells b. Dried stain crystals c. Partially digested meat fibers d. Pollen grains

9. Artifacts found in feces that can be confused with Entamoeba coli are: Multiple Choice Questions - Chapter 10

a. b. c. d.

Epithelial cells Macrophages White blood cells B or C

10. Artifacts found in feces that can be confused with Strongyloides stercoralis larva are: a. Dried stain crystals b. Partially digested meat fibers c. Plant hairs d. Vegetable spirals

11. The best method to recover pinworm eggs is the: a. Acid-fast stain b. Cellophane tape test c. Trichrome stain d. Zinc sulfate flotation method

12. Which of the following eggs is not easily recovered using the zinc sulfate technique? a. Balantidium coli b. Flagellates c. Operculated eggs d. Taenia spp. eggs

13. When using a trichrome stain to reveal parasites, an amoeba’s karyosomes will stain: a. Dark blue b. Light blue to green c. Pink d. Ruby red

14. Thick blood smears for malaria examinations are “laked” before staining by: Multiple Choice Questions - Chapter 10

a. Dipping the slide in distilled water b. Dipping the slide in methanol c. Leaving the slide in distilled water until all hemoglobin clears d. Leaving the slide in Giemsa-buffered water for 2 hours

15. If both thick and thin blood smears for malaria examination are negative, the best method to confirm the negative results is a(n): a. acid-fast stain b. buffy coat smear c. fluorescent stain d. Knott’s concentration technique

16. When filariasis is suspected, which of the following will improve the chances to recover parasites? a. Stain the smear using the modified acid-fast stain b. Stain the smear using the iron hematoxylin stain TsEaSstTaiBnANKSELLER.COM c. Stain the smear using the Giem d. Concentrate the sample using the Knott’s technique

17. Six Giardia lamblia were seen in a 10-field scanning of a trichrome-stained smear. The correct report of this finding is: a. None seen b. Few Giardia lamblia noted c. Moderate Giardia lamblia noted d. Many Giardia lamblia noted

18. The technique used to reveal microspora in fecal smears is the: a. Giemsa stain b. Knott’s technique c. Modified trichrome (Weber and Green) d. Wheatley trichrome stain

Multiple Choice Questions - Chapter 10

19. Which of the following parasites is autofluorescent? a. Microsporidia b. Cyclospora spp. c. Cryptosporidium parvum d. Isospora belli

20. All of the following parasites may have diagnostic forms present in sputum EXCEPT: a. Ascaris spp. b. Entamoeba gingivalis c. Paragonimus spp. d. Trichinella spiralis

21. The modified trichrome stain can be used to reveal microsporidia in a fecal smear. Using this technique, microsporidia will appear as: a. Black ovals, 6 to 8 µm in diamTeE teS r TBANKSELLER.COM b. Blue ovals, 4 to 6 µm in diameter c. Pink ovals, 1 to 3 µm in diameter d. Purple ovals, 8 to 10 µm in diameter

22. When using the agar plate culture method for detecting Strongyloides stercoralis, the positive culture will show: a. Color change in the medium b. Larvae growing at the edge of the inoculum c. Larval tracks made visible by bacterial growth along the track d. Increased larvae in the inoculum, as shown by washing it with 10% formalin and observing the sediment

23. The appropriate light adjustment when performing a microscopic examination of a wet mount is: a. Low light Multiple Choice Questions - Chapter 10

b. Medium light c. High light d. Phased light

24. The appropriate specific gravity for a zinc sulfate solution used in the flotation method is: a. 1.12 to 1.14 b. 1.15 to 1.17 c. 1.18 to 1.20 d. 1.21 to 1.23

25. For which of the following will serology be useful in differentiating acute from long-term infections? a. Amoebiasis b. Schistosomiasis c. Toxoplasmosis d. Trichinellosis

26. All of the following parasites or their antigens can be detected using immunology procedures EXCEPT: a. Cryptosporidium parvum b. Entamoeba histolytica c. Naegleria fowleri d. Trichomonas vaginalis

27. Which of the following stains is used to visualize fecal-concentrated smears? a. D’Antoni stain b. Giemsa stain c. Modified acid-fast stain d. Trichrome stain

Multiple Choice Questions - Chapter 10

28. All of the following fecal preservatives are suitable for acid-fast staining methods EXCEPT: a. 10% formalin b. PVA c. SAF d. Any of these are suitable

29. The culture medium used to enhance the recovery of Trypanosoma cruzi is: a. Balamuth medium b. Cleveland-Collier medium c. McQuay diphasic charcoal medium d. Novy-MacNeal-Nicolle (NNN) medium

30. Which of the following parasitic forms is most negatively affected when fecal specimens are stored at room temperature for more than 2 hours? a. Amoeba trophozoites b. Giardia lamblia cysts c. Hookworm eggs d. Whipworm eggs

Multiple Choice Questions - Chapter 10

Answer Key for Chapter 10. Clinical Laboratory Procedures

1. For which of the following parasites might the examination of as many as six specimens be needed in order to recover the parasite? a. Dientamoeba fragilis b. Entamoeba histolytica c. Giardia lamblia d. Strongyloides stercoralis ANS: C RATIONALE: G. lamblia adheres to the intestinal mucosa and appears intermittently in feces; therefore, three to six samples may be needed to successfully find the organisms.

KEY: Procedures: specimen requirements | Cognitive level: correlation

2. If patients must be purged to enhance recovery of parasites, any of the following enemics may be used EXCEPT: a. Castor oil b. Epsom salts c. Fleet phospho-soda d. Sodium sulfate ANS: A RATIONALE: Oils such as castor or mineral oil or suppositories may not be used because oil droplets will obscure the viewing of amoeba.

KEY: Procedures: specimen requirements | Cognitive level: correlation

3. The chemical found in fecal preservatives that enhances adhesion of parasites to slides prepared for trichrome stain is: a. MIF (merthiolate-iodine-formaldehyde) b. PVA (polyvinyl-alcohol) c. SAF (sodium acetate-acetic acid-formalin) d. Schaudinn solution ANS: B Multiple Choice Questions - Chapter 10

RATIONALE: PVA provides the best adhesion properties of the various preservatives listed.

KEY: Procedures: specimen preservation | Cognitive level: recall

4. When performing an ocular micrometer calibration procedure for the 40x objective, the technologist noted that the 40 mark on the ocular micrometer scale lined up exactly with the 0.09-mm line on the stage micrometer scale. The width in millimeters for each ocular scale division is: a. 0.09 mm b. 0.00225 mm c. 2.25 µm d. 40 µm ANS: C RATIONALE: Each ocular division is equal to 0.09mm/40 or 0.00225mm. Because there are 1000 µm in one millimeter, there are 2.25 µm in each ocular micrometer division (0.00225 x 1000 = 2.25).

KEY: Procedures: ocular micrometer calibration | Cognitive level: calculation

5. Charcot-Leyden crystals are occasionally observed in stool. These crystals are probably from breakdown products of: a. Eosinophils b. Lymphocytes c. Monocytes d. Neutrophils ANS: A RATIONALE: Charcot-Leyden crystals are thought to be disintegrating eosinophilic granules.

KEY: Procedures: specimen artifacts | Cognitive level: recall

6. The most sensitive method used to recover Acanthamoeba spp. from eye-care solutions or corneal samples is the: a. Giemsa stain b. Monoclonal antibody method c. Non-nutrient agar plate seeded with E. coli bacteria Multiple Choice Questions - Chapter 10

d. Novy-MacNeal-Nicolle (NNN) medium ANS: C RATIONALE: A non-nutrient agar plate seeded (inoculated) with E. coli bacteria is inoculated with a patient sample or a possibly infected eye-care solution to detect the presence of ameba. If Acanthamoeba are present, they will feed on the bacteria and propagate, leading to increased numbers of ameba, which can be observed directly on the plate when it is examined using a microscope.

KEY: Procedures: identification technique | Cognitive level: recall

7. Modified acid-fast stain is used to visualize several parasites including Cryptosporidium parvum. The modification that differentiates this method from that used to stain mycobacteria (AFB) is that in the parasite method: a. A counterstain is needed b. The stain is more concentrated c. The staining time is much longer d. The decolorizer is weaker ANS: D RATIONALE: A weaker decolorizer is needed because parasitic cells do not bind the dye as tightly as AFB cells.

KEY: Procedures: identification techniques | Cognitive level: correlation

8. Artifacts found in feces that can be confused with eggs or cysts are: a. Degenerating GI tract-lining cells b. Dried stain crystals c. Partially digested meat fibers d. Pollen grains ANS: D RATIONALE: Pollen grains commonly appear similar to eggs or cysts.

KEY: Procedures: identification findings | Cognitive level: correlation

9. Artifacts found in feces that can be confused with Entamoeba coli are: Multiple Choice Questions - Chapter 10

a. b. c. d.

Epithelial cells Macrophages White blood cells B or C

ANS: E RATIONALE: Macrophages and especially white blood cells may be confused with Entamoeba coli or Entamoeba histolytica.

KEY: Procedures: identification findings | Cognitive level: correlation

10. Artifacts found in feces that can be confused with Strongyloides stercoralis larva are: a. Dried stain crystals b. Partially digested meat fibers c. Plant hairs d. Vegetable spirals ANS: C RATIONALE: Plant hairs commonly appear similar to Strongyloides or hookworm larva.

KEY: Procedures: identification fTinEdS inTgB s |ACNoK gS niE tivLeLlE evRel.: C coOrrMelation

11. The best method to recover pinworm eggs is the: a. Acid-fast stain b. Cellophane tape test c. Trichrome stain d. Zinc sulfate flotation method ANS: B RATIONALE: Female pinworms do not release their eggs inside the host’s intestine, so eggs are not found in feces. The cellophane tape test is used to recover eggs found around the anus after migrating females leave the lower intestine and die outside the host. See text page 164.

KEY: Procedures: life cycle/identification | Cognitive level: correlation

12. Which of the following eggs is not easily recovered using the zinc sulfate technique? a. Balantidium coli Multiple Choice Questions - Chapter 10

b. Flagellates c. Operculated eggs d. Taenia spp. eggs ANS: C RATIONALE: Operculated eggs are relatively heavy and do not float well. Other nonfloaters include schistosome and infertile Ascaris spp. eggs.

KEY: Procedures: flotation technique | Cognitive level: recall

13. When using a trichrome stain to reveal parasites, an amoeba’s karyosomes will stain: a. Dark blue b. Light blue to green c. Pink d. Ruby red ANS: D RATIONALE: Various structures retain different pigments. The karyosomes appear ruby red.

Cytoplasm appears as blue-green to pink in color.

KEY: Procedures: staining techniTqE ueS|TCBoA gnNitK ivSeEleLvL elE : rRe. caC llOM

14. Thick blood smears for malaria examinations are “laked” before staining by: a. Dipping the slide in distilled water b. Dipping the slide in methanol c. Leaving the slide in distilled water until all hemoglobin clears d. Leaving the slide in Giemsa-buffered water for 2 hours ANS: D RATIONALE: Adequate exposure to Giemsa-buffered water (10 minutes) is needed to completely lyse RBCs. See text pages 168 and 209.

KEY: Procedures: staining technique | Cognitive level: recall

15. If both thick and thin blood smears for malaria examination are negative, the best method to confirm the negative results is a(n): a. acid-fast stain Multiple Choice Questions - Chapter 10

b. buffy coat smear c. fluorescent stain d. Knott’s concentration technique ANS: B RATIONALE: When neither thick nor thin blood smears for malaria examination reveal parasites, preparing a buffy coat smear may concentrate parasites, leading to a positive recovery of a low-level malaria infection.

KEY: Procedures: concentration/staining technique | Cognitive level: recall

16. When filariasis is suspected, which of the following will improve the chances to recover parasites? a. Stain the smear using the modified acid-fast stain b. Stain the smear using the iron hematoxylin stain c. Stain the smear using the Giemsa stain d. Concentrate the sample using the Knott’s technique ANS: D RATIONALE: The Knott’s technTiqEuS eT coBnAceNnK trS atE esLbLloEoR d.pC arO asMites by centrifuging the blood sample before staining the concentrate with Giemsa stain. See text page 169.

KEY: Procedures: staining technique | Cognitive level: recall

17. Six Giardia lamblia were seen in a 10-field scanning of a trichrome-stained smear. The correct report of this finding is: a. None seen b. Few Giardia lamblia noted c. Moderate Giardia lamblia noted d. Many Giardia lamblia noted ANS: C RATIONALE: The usual key for reporting significant findings is ≤ 2, few; 3–9, moderate; > 10, many.

KEY: Procedures: specimen reporting | Cognitive level: correlation

Multiple Choice Questions - Chapter 10

18. The technique used to reveal microsporidia in fecal smears is the: a. Giemsa stain b. Knott’s technique c. Modified trichrome (Weber and Green) d. Wheatley trichrome stain ANS: C RATIONALE: Microsporidia do not stain using the Wheatley trichrome stain. Weber and Green modified the Wheatley trichrome stain by increasing the chromotrope 2R dye concentration and increasing the staining time to correct this problem.

KEY: Procedures: staining technique | Cognitive level: recall

19. Which of the following parasites is autofluorescent? a. Microsporidia b. Cyclospora spp. c. Cryptosporidium parvum d. Isospora belli ANS: B RATIONALE: Only Cyclospora spp. autofluoresces, which is a useful characteristic because it is acid-fast variable. The other parasites are revealed by acid-fast stain.

KEY: Procedures: parasite identification | Cognitive level: recall

20. All of the following parasites may have diagnostic forms present in sputum EXCEPT: a. Ascaris spp. b. Entamoeba gingivalis c. Paragonimus spp. d. Trichinella spiralis ANS: D RATIONALE: T. spiralis larvae penetrate blood vessels and then travel directly to tissues. The larvae of Ascaris spp. and hookworms migrate through the liver to the lungs before returning to the intestinal tract. Paragonimus spp. adults migrate to the lungs and release eggs into the bronchi, which are recovered in sputum.

KEY: Procedures: sample types/life cycles | Cognitive level: correlation

Multiple Choice Questions - Chapter 10

21. The modified trichrome stain can be used to reveal microsporidia in a fecal smear. Using this technique, microsporidia will appear as: a. Black ovals, 6 to 8 µm in diameter b. Blue ovals, 4 to 6 µm in diameter c. Pink ovals, 1 to 3 µm in diameter d. Purple ovals, 8 to 10 µm in diameter ANS: C RATIONALE: Microsporidia do not stain well using regular trichrome staining, but the KoKoskin, Ryan, or Weber modifications allow microsporidia to be visualized as pink oval organisms measuring 1 to 3 µm in diameter.

KEY: Techniques: trichrome stain | Cognitive level: correlation

22. When using the agar plate culture method for detecting Strongyloides stercoralis, the positive culture will show: a. Color change in the medium KSELLER.COM b. Larvae growing at the edge ofTthEeSinToBcA ulN um c. Larval tracks made visible by bacterial growth along the track d. Increased larvae in the inoculum, as shown by washing it with 10% formalin and observing the sediment ANS: C RATIONALE: Larvae move away from the inoculum and drag fecal bacteria that will grow on the plate, forming visible tracks. The tracks are washed with 10% formalin and the sediment is examined for the presence of larvae.

KEY: Procedures: identification techniques | Cognitive level: recall

23. The appropriate light adjustment when performing a microscopic examination of a wet mount is: a. Low light b. Medium light c. High light d. Phased light

Multiple Choice Questions - Chapter 10

ANS: A RATIONALE: Unstained organisms such as amoeba are translucent; therefore, low light is needed in order to provide good contrast for successful viewing.

KEY: Procedures: microscopy | Cognitive level: correlation

24. The appropriate specific gravity for a zinc sulfate solution used in the flotation method is: a. 1.12 to 1.14 b. 1.15 to 1.17 c. 1.18 to 1.20 d. 1.21 to 1.23 ANS: C RATIONALE: The correct specific gravity range for the zinc sulfate solution is 1.18 to 1.20.

Eggs and parasites will not be recovered if the specific gravity of the flotation solution is incorrect.

KEY: Procedures: reagent preparation | Cognitive level: recall

25. For which of the following will serology be useful in differentiating acute from long-term infections? a. Amoebiasis b. Schistosomiasis c. Toxoplasmosis d. Trichinellosis ANS: C RATIONALE: Comparison of IgG and IgM titers for Toxoplasma gondii can be used to distinguish among acute, recent, and long-term infections. Positive serology can be used to confirm the diagnosis for the other mentioned infections.

KEY: Procedures: serology results | Cognitive level: correlation

26. All of the following parasites or their antigens can be detected using immunology procedures EXCEPT: a. Cryptosporidium parvum b. Entamoeba histolytica Multiple Choice Questions - Chapter 10

c. Naegleria fowleri d. Trichomonas vaginalis ANS: C RATIONALE: Naegleria fowleri currently can be detected using a DNA probe. The other parasites can be detected using immunoassay methods.

KEY: Procedures: serology methods | Cognitive level: recall

27. Which of the following stains is used to visualize fecal-concentrated smears? a. D’Antoni stain b. Giemsa stain c. Modified acid-fast stain d. Trichrome stain ANS: A RATIONALE: A simple iodine stain, D’Antoni stain, is used for staining fecal direct mounts and concentrated samples. The other stains are used for other purposes.

KEY: Procedures: stain usage | Cognitive level: recall

28. All of the following fecal preservatives are suitable for acid-fast staining methods EXCEPT: a. 10% formalin b. PVA c. SAF d. Any of these are suitable ANS: B RATIONALE: Formalin, SAF, and direct-mount preparations are satisfactory for acid-fast staining methods. PVA is not suitable.

KEY: Procedures: stain usage | Cognitive level: recall

29. The culture medium used to enhance the recovery of Trypanosoma cruzi is: a. Balamuth medium b. Cleveland-Collier medium Multiple Choice Questions - Chapter 10

c. McQuay diphasic charcoal medium d. Novy-MacNeal-Nicolle (NNN) medium ANS: D RATIONALE: NNN will support the growth of T. cruzi and Leishmania spp. All the other media are used to grow intestinal protozoa such as E. histolytica.

KEY: Procedures: culture techniques | Cognitive level: recall

30. Which of the following parasitic forms is most negatively affected when fecal specimens are stored at room temperature for more than 2 hours? a. Amoeba trophozoites b. Giardia lamblia cysts c. Hookworm eggs d. Whipworm eggs ANS: A RATIONALE: Amoeba trophozoites are fragile and die rapidly if they are not preserved in 10% formalin or other preservatives. Hookworm eggs may hatch if feces are allowed to remain at KySsE Rh.ipCwOoMrm eggs will remain viable in room temperature for more than 1TtEoS2TdB ayAsN .C tsLanLdEw formed stool for extended periods.

KEY: Procedures: specimen storage | Cognitive level: correlation

Multiple Choice Questions - Chapter 10

Chapter 11. Control and Treatment of Parasitic Disease

1. A disease that occurs continuously or in predictable cycles, with a predictable number of cases, is known as: a. Endemic b. Epidemic c. Pathogenic d. Virulent

2. A pathogenic disease that attacks many people in the same geographic region over a short period of time is referred to as: a. Endemic b. Epidemic c. Pathogenic d. Virulent

3. Because people strain their water through a T-shirt before drinking it, cooking with it, or using it for other personal purposes, Dracunculus medinensis has almost been eliminated from parts of the Mediterranean region. This control measure is an example of: a. Barrier control b. Chemical treatment or cleaning of the environment c. Life-cycle interruption d. Prophylactic treatment of hosts

4. Travelers to Africa are advised to take chloroquine phosphate before beginning the trip and continuing the medication while in Africa. This action is an example of: a. Barrier control b. Chemical treatment or cleaning of the environment c. Life-cycle interruption d. Prophylactic treatment of hosts

Multiple Choice Questions - Chapter 11

5. Wearing shoes when walking in soil that may be contaminated with hookworm or Strongyloides larvae and using mosquito nets when camping are examples of: a. Barrier control b. Chemical treatment or cleaning of the environment c. Life-cycle interruption d. Prophylactic treatment of hosts

6. An immunocompromised patient with AIDS was admitted to the hospital with pneumonia and bacteremia. In addition to blood and sputum cultures, the physician also ordered a fecal examination for eggs and parasites to rule out infection with: a. Enterocytozoon bieneusi b. Cryptosporidium parvum c. Strongyloides stercoralis d. Toxoplasma gondii

Multiple Choice Questions - Chapter 11

Answer Key for Chapter 11. Control and Treatment of Parasitic Disease

1. A disease that occurs continuously or in predictable cycles, with a predictable number of cases, is known as: a. Endemic b. Epidemic c. Pathogenic d. Virulent ANS: A RATIONALE: Endemic disease is present in an area all the time, and it is expected that infected individuals will be found at some level all the time. Epidemics are sudden events.

KEY: Control and Treatment: definition | Cognitive level: recall

2. A pathogenic disease that attacks many people in the same geographic region over a short period of time is referred to as: a. Endemic b. Epidemic c. Pathogenic d. Virulent ANS: B RATIONALE: Epidemics occur as sudden events and affect a significant number of people.

Parasitic agents may be endemic or newly introduced into the area.

KEY: Control and Treatment: definition | Cognitive level: recall

3. Because people strain their water through a T-shirt before drinking it, cooking with it, or using it for other personal purposes, Dracunculus medinensis has almost been eliminated from parts of the Mediterranean region. This control measure is an example of: a. Barrier control b. Chemical treatment or cleaning of the environment c. Life-cycle interruption d. Prophylactic treatment of hosts Multiple Choice Questions - Chapter 11

ANS: C RATIONALE: Straining water obtained directly from natural sources such as river water breaks the parasite’s life cycle by removing the infected copepod (intermediate host) from the water, thus preventing ingestion of the infective form. The other mentioned strategies are less effective or more expensive ways to control this parasite.

KEY: Control and Treatment: life-cycle interruption | Cognitive level: correlation

4. Travelers to Africa are advised to take chloroquine phosphate before beginning the trip and continuing the medication while in Africa. This action is an example of: a. Barrier control b. Chemical treatment or cleaning of the environment c. Life-cycle interruption d. Prophylactic treatment of hosts ANS: D RATIONALE: By prescribing a prophylactic drug for travelers, if a parasite is encountered, the drug will kill the parasite before it can establish an infection. By continuing the treatment after the traveler leaves the endemic arTeaE,SthTeB reAwNilKl S beEcLoL ntE inRu. edCpOreMvention so that any last-minute invasion by a parasite will also be counteracted.

KEY: Control and Treatment: prophylactic treatment | Cognitive level: correlation

5. Wearing shoes when walking in soil that may be contaminated with hookworm or Strongyloides larvae and using mosquito nets when camping are examples of: a. Barrier control b. Chemical treatment or cleaning of the environment c. Life-cycle interruption d. Prophylactic treatment of hosts ANS: A RATIONALE: Barrier protection separates the prospective host from the infective form of the parasite, thus preventing infection.

KEY: Control and Treatment: barrier protection | Cognitive level: correlation

Multiple Choice Questions - Chapter 11

6. An immunocompromised patient with AIDS was admitted to the hospital with pneumonia and bacteremia. In addition to blood and sputum cultures, the physician also ordered a fecal examination for eggs and parasites to rule out infection with: a. Enterocytozoon bieneusi b. Cryptosporidium parvum c. Strongyloides stercoralis d. Toxoplasma gondii ANS: C RATIONALE: A compromised immune system allows for a new or subclinical Strongyloides infection to become increasingly severe. As larvae leave the intestine to invade the bloodstream, they drag along bacteria, which lead to bacteremia and other related infections such as pneumonia.

KEY: Control and Treatment: immunocompromised patient | Cognitive level: correlation

Multiple Choice Questions - Chapter 11