ICVA - International Council for Veterinary Assessment Zoonotic Diseases Public Health Questions and Answers 1 — Questions and Answers
Question 1: A veterinarian is advising a pregnant client about reducing her risk of acquiring toxoplasmosis. The client owns a healthy, indoor-only cat. Which of the following recommendations is the most accurate and crucial?
- Rehome the cat for the duration of the pregnancy to eliminate risk.
- Have another member of the household clean the litter box daily. (Correct answer)
- Test the cat's blood for Toxoplasma antibodies to determine if it is a risk.
- The risk is negligible because the cat is kept exclusively indoors.
Correct answer: Have another member of the household clean the litter box daily.
The most common routes of human infection with *Toxoplasma gondii* are eating undercooked contaminated meat and accidental ingestion of oocysts from the environment. Cats shed oocysts in their feces for a short period after initial infection. These oocysts take 1-5 days to sporulate and become infectious. Therefore, having a non-pregnant, non-immunocompromised person change the litter box daily removes the feces before the oocysts become infective, significantly reducing the risk of transmission. While indoor cats have a lower risk, they can still become infected (e.g., by eating a mouse that entered the house). Rehoming the cat is unnecessary, and serology on the cat is not a reliable indicator of current oocyst shedding.
Question 2: A public health investigation is initiated after several farmworkers develop an acute febrile illness with severe headaches and pneumonia. The investigation links the outbreak to assisting with goat and sheep births on the farm. Which zoonotic agent is the most likely cause?
- *Brucella melitensis*
- *Bacillus anthracis*
- *Coxiella burnetii* (Correct answer)
- *Leptospira interrogans*
Correct answer: *Coxiella burnetii*
*Coxiella burnetii*, the causative agent of Q fever, is shed in very high concentrations in the placenta, amniotic fluid, and other birth products of infected ruminants, particularly sheep and goats. Transmission to humans occurs primarily through the inhalation of infectious aerosols generated during parturition. This history is classic for a Q fever outbreak. While the other agents are zoonotic, they are less likely; *Brucella* is also associated with reproductive tissues but often presents differently, anthrax inhalation is rare from this activity, and leptospirosis is typically associated with contaminated urine or water.
Question 3: A healthy, unvaccinated 4-month-old puppy bites a child, causing a minor skin abrasion. The puppy is apprehended and appears healthy. According to the Compendium of Animal Rabies Prevention and Control, which of the following is the most appropriate public health action?
- Immediately euthanize the puppy and submit the head for rabies testing.
- Administer post-exposure prophylaxis (PEP) to the child immediately without observing the animal.
- Release the puppy to the owner with instructions to vaccinate it for rabies immediately.
- Quarantine the puppy for 10 days and observe it for clinical signs of rabies. (Correct answer)
Correct answer: Quarantine the puppy for 10 days and observe it for clinical signs of rabies.
For a healthy-appearing dog, cat, or ferret that bites a person, the standard recommendation is a 10-day confinement and observation period, regardless of the animal's vaccination status. This is because rabies virus is shed in the saliva concurrently with or for only a few days before the onset of clinical signs. If the animal remains healthy for 10 days, it could not have transmitted rabies at the time of the bite, and the bite victim does not require post-exposure prophylaxis. Euthanasia is only recommended if the animal is a stray, develops signs of rabies, or if observation is not possible. Rabies vaccination should not be given during the quarantine period as adverse reactions could be confused with signs of rabies.
Question 4: A 5-year-old child presents with severe, progressive neurological signs, including ataxia and encephalitis. The family lives in a wooded suburban area and recently cleaned out an old shed frequently used by raccoons as a latrine. Which zoonotic parasite is the most likely cause of neural larva migrans in this case?
- *Toxocara canis*
- *Baylisascaris procyonis* (Correct answer)
- *Ancylostoma caninum*
- *Echinococcus granulosus*
Correct answer: *Baylisascaris procyonis*
*Baylisascaris procyonis*, the raccoon roundworm, is a well-documented cause of severe and often fatal neural larva migrans (NLM) in humans and other paratenic hosts. Humans, especially children with a history of pica or geophagia, become infected by ingesting infective eggs from environments contaminated with raccoon feces. The larvae are large, aggressive, and have a tendency to migrate to the central nervous system, causing extensive damage. While *Toxocara canis* can cause visceral and ocular larva migrans, severe NLM is much less common compared to *B. procyonis*.
Question 5: A veterinarian in the United States diagnoses a cow with clinical signs highly suggestive of Foot-and-Mouth Disease (FMD), a foreign animal disease. What is the immediate and most critical professional and legal responsibility of the veterinarian?
- Initiate treatment with broad-spectrum antibiotics and supportive care.
- Advise the producer to immediately cull and bury the affected animal.
- Report the suspicion immediately to the State Animal Health Official and/or the USDA-APHIS Area Veterinarian in Charge. (Correct answer)
- Collect samples and send them via a commercial courier to a private diagnostic laboratory.
Correct answer: Report the suspicion immediately to the State Animal Health Official and/or the USDA-APHIS Area Veterinarian in Charge.
Veterinarians have a legal and ethical obligation to immediately report any suspected or confirmed case of a foreign or reportable animal disease to the appropriate authorities. In the U.S., this means contacting the State Animal Health Official (SAHO) and/or the USDA-APHIS Area Veterinarian in Charge (AVIC). This immediate reporting is critical to trigger an official investigation and implement control and eradication measures to protect national livestock, public health, and trade. All other actions, such as treatment or independent sampling, are inappropriate and could delay the official response or spread the disease.
Question 6: Which of the following scenarios best exemplifies the application of the One Health concept?
- A public health department issues a boil water advisory after a municipal water main breaks.
- A veterinarian vaccinates a kennel of dogs against *Bordetella bronchiseptica*.
- Physicians, veterinarians, and wildlife biologists collaborate to track the spread of Lyme disease by monitoring tick populations, deer movements, and human cases. (Correct answer)
- An equine surgeon develops a new technique for arthroscopic joint surgery.
Correct answer: Physicians, veterinarians, and wildlife biologists collaborate to track the spread of Lyme disease by monitoring tick populations, deer movements, and human cases.
One Health is a collaborative, multisectoral, and transdisciplinary approach that recognizes the interconnection between the health of people, animals, and their shared environment. The correct answer demonstrates this principle by involving professionals from human health (physicians), animal health (veterinarians), and environmental/ecosystem health (wildlife biologists) to address a complex zoonotic disease issue at the interface of all three domains. The other options represent important activities within a single domain (public health, veterinary medicine, or surgery) but do not illustrate the integrated, cross-sectoral collaboration that defines One Health.
ICVA - International Council for Veterinary Assessment Zoonotic Diseases Public Health Questions and Answers 1
A veterinarian is advising a pregnant client about reducing her risk of acquiring toxoplasmosis.
The client owns a healthy, indoor-only cat.
Which of the following recommendations is the most accurate and crucial?