ICVA Zoonotic Diseases Public Health 3 — Questions and Answers
Question 1: Under the National Notifiable Animal Diseases list, which zoonotic disease requires veterinarians to report within 24 hours in most US states?
- Rabies (Correct answer)
- Leptospirosis
- Ringworm (dermatophytosis)
- Campylobacteriosis
Correct answer: Rabies
Rabies is an immediately notifiable disease requiring 24-hour reporting in virtually all US jurisdictions due to its near-100% case fatality rate and public health implications.
Question 2: A food inspector detects Escherichia coli O157:H7 in a ground beef sample. Which virulence factor makes this strain particularly dangerous to public health?
- Shiga toxin production causing hemolytic uremic syndrome (Correct answer)
- Ability to form spores that survive normal cooking temperatures
- Production of botulinum-like neurotoxin affecting the central nervous system
- Antibiotic resistance to all beta-lactam and fluoroquinolone antibiotics
Correct answer: Shiga toxin production causing hemolytic uremic syndrome
E. coli O157:H7 produces Shiga toxins (Stx1 and Stx2) that can cause hemolytic uremic syndrome (HUS), a life-threatening complication especially in children.
Question 3: Veterinarians performing necropsies on wildlife should take precautions against which zoonosis transmitted through contact with infected tissues, particularly in lagomorphs and rabbits?
- Tularemia (Francisella tularensis) (Correct answer)
- Plague (Yersinia pestis)
- Lyme disease (Borrelia burgdorferi)
- Anaplasmosis (Anaplasma phagocytophilum)
Correct answer: Tularemia (Francisella tularensis)
Francisella tularensis can penetrate intact skin and mucous membranes during necropsy of infected rabbits or other lagomorphs, making gloves and eye protection essential.
Question 4: Which principle guides the decision to use post-exposure prophylaxis (PEP) after a potential rabies exposure from a domestic dog?
- Observe the dog for 10 days; PEP is unnecessary if the animal remains healthy (Correct answer)
- Immediately begin PEP regardless of the animal's vaccination status
- PEP is only warranted if the bite breaks the skin and draws blood
- Euthanize the dog and test brain tissue before making any PEP decision
Correct answer: Observe the dog for 10 days; PEP is unnecessary if the animal remains healthy
A healthy dog that bit someone can be observed for 10 days; if it remains healthy, the animal was not shedding rabies virus at the time of the bite, and PEP is not needed.
Question 5: Psittacosis (parrot fever) is caused by which obligate intracellular organism and is reportable in most US states?
- Chlamydia psittaci (Correct answer)
- Chlamydia trachomatis
- Mycoplasma psittaceus
- Rickettsia prowazekii
Correct answer: Chlamydia psittaci
Chlamydia psittaci infects psittacine birds and can cause severe pneumonia in humans who inhale aerosolized bird droppings or respiratory secretions.
Question 6: Which zoonotic helminth causes visceral larva migrans in children who ingest embryonated eggs from contaminated soil?
- Toxocara canis (Correct answer)
- Ancylostoma caninum
- Dipylidium caninum
- Echinococcus granulosus
Correct answer: Toxocara canis
Toxocara canis larvae from embryonated dog roundworm eggs migrate through human tissues causing visceral larva migrans, with ocular larva migrans being a serious complication.
Question 7: A veterinarian treating a febrile cat colony discovers the cats are seropositive for Toxoplasma gondii. Which human population faces the greatest risk of severe disease from this zoonosis?
- Immunocompromised individuals and pregnant women in their first trimester (Correct answer)
- Elderly adults over age 70 with intact immune systems
- Children under age 5 with no prior exposure to cats
- Veterinary students with frequent cat contact but no immunosuppression
Correct answer: Immunocompromised individuals and pregnant women in their first trimester
Toxoplasma gondii causes severe congenital defects in fetuses and life-threatening encephalitis in immunocompromised hosts such as HIV/AIDS patients.
ICVA Zoonotic Diseases Public Health 3
Under the National Notifiable Animal Diseases list, which zoonotic disease requires veterinarians to report within 24 hours in most US states?