A Zoonotic Sampler Worldwide, roughly 75 percent of human pathogens are zoonotic and can pass from animals to humans, with new diseases emerging at an increasingly rapid pace. Below is a sampling of some of these diseases and their causative agents, hosts, and routes of transmission, followed by tips on preventing contraction or spread of zoonotic disease. Disease
Causative agent
Transmission route
Hantavirus pulmonary syndrome
Hantaviruses
Inhalation of virus shed in the waste of Peromyscus species and other rodents
West Nile virus
Flavivirus - West Nile virus
Bites from mosquitoes that have fed on infected birds
Rabies
Lyssavirus - Rabies virus
A bite from an infected mammal
Bartonellosis
Bacteria of the genus Bartonella
Bites and scratches from various mammals; transmission by ectoparasites (skin parasites) suspected
Typhus plague
Rickettsia typhi and R. felis bacteria Yersinia pestis bacteria
Fleas feeding on infected rodents (both) and opossums (typhus)
Undulant fever
Bacteria of the genus Brucella
Contact with tissues, blood, urine, vaginal discharges, or fetuses of infected animals such as deer and swine
Tularemia
Francisella tularensis bacteria
Inhalation or ingestion of bacteria from infected rodents and lagomorphs; also, bites from infected flies or ticks
Leptospirosis
Bacteria of the genus Leptospira
Invasion of skin by bacteria passed in the urine of various mammals; contact with contaminated water, food, or soil
Salmonellosis
Bacteria of the genus Salmonella
Ingestion of food or water contaminated with mammal and bird feces
Visceral and ocular larval migrans
Roundworms of the genus Baylisascaris
Ingestion of larvated eggs present in raccoon, skunk, and bear feces
Giardiasis
Parasites of the genus Giardia
Ingestion of food or water contaminated with bird and mammal feces containing oocysts of certain protists; ingestion of undercooked infected meat
Cryptosporidiosis Toxoplasmosis
Parasites of the genus Cryptosporidium Toxoplasma gondii parasite
Ingestion of food or water contaminated with bird and mammal feces containing oocysts of certain protists; ingestion of undercooked infected meat
Trichinosis/Trichinellosis
Parasites of the genus Trichinella
Ingestion of the undercooked infected meat of mammals
Echinococcosis or Hydatid disease
Echinococcus multilocularis and E. granulosus tapeworms
Ingestion of food or water contaminated with eggs from canid and felid feces; canids and felids can contract the parasite by eating infected rodents or cervids
Histoplasmosis
Histoplasma capsulatum fungus
Inhalation of infective spores found in bird and bat feces
Tick-borne illnesses Powassan virus Lyme disease Relapsing fever borreliosis Ehrlichiosis Rickettsiosis (American boutonneuse fever) Rickettsiosis (Rocky Mountain spotted fever)
Flavivirus - Powassan virus Borrelia burgdorferi bacterium Borrelia hermsii and rarely other Borrelia bacteria Ehrlichia chaffeensis, E. ewingii bacteria R. parkeri bacteria Rickettsia rickettsi
All from bites from ticks that have fed on infected reservoirs (such as white-tailed deer, rodents, or other small mammals); tick species include Ixodes scapularis, I. pacificus, Ornithodoros species, Amblyomma americanum, A. maculatum, and Dermacentor variabilis
Credit: Michael J. Yabsley
Baylisascaris procyonis, causes larval migrans
Credit: Michael J. Yabsley
Trypomastigotes of Trypanosoma cruzi, causes Chagas disease
Credit: Michael J. Yabsley
Trichinella spiralis in muscle, causes trichinosis
Credit: J.P. Bond
Amblyomma americanum tick, can transmit Ehrlichia and other pathogens
An Ounce of Prevention Wildlife professionals and others can take basic precautions to minimize their risk of contracting a zoonotic disease. These include wearing basic protective gear such as gloves when handling potentially infected wildlife, blood, or feces. Masks can help prevent inhalation of particulates from dried feces, blood, or urine, which may contain parasites, viral agents, or bacteria. Using appropriate equipment to restrain wildlife can help prevent scratches and bites. Likewise, repellents and protective clothing can prevent bites from mosquitoes, fleas, lice, and ticks. To prevent ingestion of disease-causing agents, wildlife professionals should avoid potentially contaminated food and water, cook harvested meat properly, and never feed potentially infected wildlife carcasses to other animals.
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The Wildlife Professional, Spring 2012
Š The Wildlife Society