Human Zoonotic Pathogens

Question 1

Ancylostoma spp.

Answer 1

type of hookworm that causes cutaneous larval migrans

infects and causes dermatitis in children walking barefoot through fields

Question 2

Ascaris suum

Answer 2

roundworm of pigs; infection in humans is very rare and signs are neurologic or hematologic

Question 3

Bartonellosis henselae

Answer 3

“cat scratch fever,” the owner is infected with the bacteria from flea feces when the cat bites or scratches the owner. Commonly, the bacteria cause fever, malaise, weight loss, and lymphadenopathy. Often, cats show no clinical signs. Dogs can be exposed via tick or flea vector and show signs similar to humans, including possible endocarditis.

Question 4

Baylisascaris procyonis

Answer 4

Ascarid (roundworm) found in the small intestine of raccoons. The results in humans is larval migrans to the brain causing CNS disease. It may migrate to the eye and usually affects children.

Question 5

Campylobacter

Answer 5

food borne pathogen, not in milk

Question 6

Chlamydophila psattaci

Answer 6

respiratory psittacosis in humans

Question 7

Clostridium botulinum

Answer 7

Causes primary nervous system signs

Question 8

Coxiella burnetii

Answer 8

Small gram negative spore-forming intracellular bacterium acquired from sheep, “Q fever” in humans causes fever, headache, fatigue, premature delivery, or abortions.

Question 9

Cutaneous larval migrans

Answer 9

Hookworm

Question 10

E. coli 0157:H7

Answer 10

Produces “shiga-like toxins” - food borne pathogen causes hemorrhagic diarrhea and is associated with hemolytic uremic syndrome (HSU) in susceptible individuals

Question 11

Francisella tularensis

Answer 11

“Rabbit fever” rabbit is natural host

Question 12

Guillian-Barre Syndrome

Answer 12

Inflammatory demyelination polyneuropathy in humans due to food-borne pathogen - Campylobacter jejuni

Question 13

Hepatitis A virus

Answer 13

Typically causes mild signs but can cause liver damage, fatigue, and jaundice

Question 14

Herpes simiae

Answer 14

relatively non-pathogenic in macaques, can cause fatal encephalitis if transmitted to humans. Herpes B virus. Old world monkeys can transmit this disease by bite or scratch. Macaques are the most frequent carriers. In monkeys, the disease can cause mild sore like lesions in times of stress. The strain of herpes is potentially fatal to humans. Similarly, humans carry a strain of herpes (herpes simplex virus) which can cause fatal encephalitis in monkeys.

Question 15

Influenza virus gene from bird to human strain

Answer 15

Some of the genes can transfer from a bird strain into a human strain, thus producing a much more virulent strain that can affect humans. Influenza virus strains can readily exchange genes, especially between turkey strains and swine flu, but also between duck strains and swine flu or even duck flu and human influenza virus. These re-assorted new strains can prove highly virulent.

Question 16

Listeria nenocytogenes

Answer 16

food borne pathogen; can cause fever and muscle aches, but it only sometimes causes gastrointestinal signs such as nausea and diarrhea.

Question 17

Shigella

Answer 17

food borne pathogen, a genus of Gram-negative, facultative anaerobic, nonspore-forming, nonmotile, rod-shaped bacteria genetically closely related to E. coli, main sign is diarrhea

Question 18

Taenia solium

Answer 18

swine cysticercosis in humans; occurs with ingestions of infected pork that is inadequately cooked containing cysticerci (larval stage). They evaginate and attach to the small intestine. The adult tapeworms develope (Taeniasis) but cannot complete life cycle until they are consumed in the cyst form (from pork) versus direct ingestion.

Question 19

Toxocara canis

Answer 19

roundworm - children’s eyes, visceral larval migrans

Question 20

True Creutzfeldt-Jakob Disease (CJD)

Answer 20

rare disorder that can occur due to a genetic mutation or may occur sporadically. Patients may experience psychiatric symptoms such as depression or a schizophrenia-like psychosis. Unusual sensory symptoms may also occur. Neurological signs progress to difficulty walking and involuntary movements, and, by the time of death, patients become completely immobile and mute.

Question 21

Variant Creutzfeldt-Jakob Disease (vCJD)

Answer 21

typically affects younger people and has been strongly linked to exposure, probably through food, to cattle BSE

Question 22

Visceral larval migrans

Answer 22

round worms, toxocara

Question 23

Yersinia enterocalitiea

Answer 23

food borne pathogen; severe abdominal pain and fever, acquired from eating pork

Question 24

Echinococcus granulosus

Answer 24

Parasite in dog that causes hydatid cyst disease in humans, which can be fatal. A hydatid tapeworm which is non-pathogenic in dogs but it highly pathogenic to fatal in humans and other intermediate hosts in which a hydatid cyst forms. The infection is acquired in dogs by eating raw sheep meat of viscera infected with the parasite. All dogs suspected of being infected should be treated with praziquantel.

Question 25

Sarcocystis hominis

Answer 25

Ruminant intermediate host, human definitive host