SAVC Registration Examination Veterinary Epidemiology & Zoonoses: practice questions

1 · Measures of disease frequency: incidence, prevalence, morbidity, mortality and case fatality · easy

During an outbreak of respiratory disease, 40 calves become ill and 6 of them die. What is the case fatality rate?

1. 6%
2. 17.6%
3. 40%
4. 15%

2 · Epidemiological study designs · medium

A case-control study of salmonellosis in herds gives: cases exposed 40, cases unexposed 60, controls exposed 20, controls unexposed 80. What is the odds ratio?

1. 2.67
2. 1.56
3. 2.00
4. 0.38

3 · Surveillance · easy

A national system relies on farmers and private veterinarians to report suspect cases of disease to the veterinary authority. This is:

1. Passive surveillance
2. Targeted active surveillance
3. Sentinel surveillance
4. Participatory surveillance

4 · Risk analysis · medium

Under the WTO SPS Agreement, if a country wants an import measure stricter than the relevant WOAH standard, it must:

1. Obtain approval from FAO
2. Show that the exporting country has no veterinary service
3. Apply the same measure to all trading partners regardless of disease status
4. Justify it with a scientific risk assessment

5 · Outbreak investigation · medium

In a feed-associated outbreak, 80 broilers received a particular batch of feed and 20 became ill. What is the attack rate among birds that received it?

1. 20%
2. 4%
3. 25%
4. 80%

6 · Zoonoses: rabies, brucellosis, tuberculosis and anthrax · easy

A cow is found dead with dark unclotted blood oozing from the nostrils and anus and no rigor mortis. What should be done first?

1. Perform a full necropsy at once to examine the spleen for enlargement and to collect tissue samples from every organ
2. Skin the carcass carefully to salvage the hide, then bury the remains at least two metres deep on the same farm
3. Do not open the carcass; take a peripheral blood smear for polychrome methylene blue stain and inform the authorities
4. Send the carcass for rendering without delay so that no other animals can feed on it

7 · Zoonoses: leptospirosis, glanders, KFD, avian influenza and Japanese encephalitis · medium

Why are H5 and H7 low pathogenicity avian influenza viruses in poultry a regulatory concern?

1. They are always highly pathogenic for humans and spread readily from person to person after any exposure to poultry
2. HPAI viruses have so far arisen only from H5 and H7 subtypes, which can mutate to high pathogenicity in poultry
3. They cannot be detected by any laboratory test, so infected flocks go unnoticed until they die
4. They infect only mammals

8 · Transboundary animal diseases and WOAH · hard

Which event does NOT by itself require an immediate notification to WOAH?

1. The first occurrence of a listed disease in a zone previously recognised as free
2. Recurrence of a listed disease after the country had previously declared it eradicated
3. The first occurrence of a new strain of the agent of a listed disease in the country
4. A continuing, stable level of a listed disease already reported as present

9 · Surveillance · easy

Planned testing of a random sample of herds by the veterinary authority to measure brucellosis prevalence is an example of:

1. Passive surveillance
2. Syndromic surveillance
3. Active surveillance
4. Participatory surveillance

10 · Surveillance · easy

Planned testing of a random sample of herds by the veterinary authority to measure brucellosis prevalence is an example of:

1. Passive surveillance
2. Syndromic surveillance
3. Active surveillance
4. Participatory surveillance