Vet Epidemiology Test Bank PDF

**1. Which of the following best describes a \"sporadic\" disease occurrence?** a\) A disease that occurs regularly in the population\ b) A disease that appears irregularly and haphazardly\ c) A sudden outbreak of disease\ d) A disease that persists at a constant level **Answer:** b) A disease tha...

**1. Which of the following best describes a \"sporadic\" disease occurrence?** a\) A disease that occurs regularly in the population\ b) A disease that appears irregularly and haphazardly\ c) A sudden outbreak of disease\ d) A disease that persists at a constant level **Answer:** b) A disease that appears irregularly and haphazardly **2. What is the primary feature of an \"epidemic\" in epidemiology?** a\) Occurrence of disease at regular intervals\ b) Clustering of cases in space but not time\ c) Occurrence of disease in excess of the expected level\ d) Disease that remains endemic with no fluctuations **Answer:** c) Occurrence of disease in excess of the expected level **3. Which epidemiological classification refers to the usual frequency of a disease in a population?** a\) Pandemic\ b) Endemic\ c) Epidemic\ d) Sporadic **Answer:** b) Endemic **4. What is a key factor that distinguishes an epidemic from a pandemic?** a\) Time duration\ b) Geographical spread\ c) Host factors\ d) Severity of the disease **Answer:** b) Geographical spread **5. In which of the following situations does a disease become hyperendemic?** a\) It affects a small proportion of the population\ b) It affects a moderate proportion of the population\ c) It affects a high proportion of the population\ d) It spreads rapidly across multiple regions **Answer:** c) It affects a high proportion of the population **6. What is the significance of the term \"epidemiological unit\"?** a\) It refers to individual animals that have contracted the disease\ b) It refers to a group of animals sharing the same likelihood of exposure\ c) It refers to the environmental factors that cause the disease\ d) It refers to the time when the disease was first detected **Answer:** b) It refers to a group of animals sharing the same likelihood of exposure **7. Which term best describes the introduction of a novel pathogen to a previously unexposed population?** a\) Endemic\ b) Hyperendemic\ c) Epidemic\ d) Pandemic **Answer:** c) Epidemic **8. What factor is NOT typically associated with an epidemic occurrence?** a\) Introduction of a susceptible group of animals into an infected area\ b) Recent increase in virulence of the pathogen\ c) Constant presence of disease in the population\ d) New portal of entry for the pathogen **Answer:** c) Constant presence of disease in the population **9. Which disease pattern is characterized by predictable regularity in its occurrence but low levels?** a\) Hyperendemic\ b) Pandemic\ c) Sporadic\ d) Endemic **Answer:** d) Endemic **10. In a \"mesoendemic\" disease pattern, how much of the population is typically affected?** a\) None\ b) A small proportion\ c) A moderate proportion\ d) A high proportion **Answer:** c) A moderate proportion **11. Which of the following does NOT contribute to the spread of a pandemic?** a\) International travel\ b) Close animal-human interaction\ c) Stable environmental factors\ d) Introduction of a novel pathogen **Answer:** c) Stable environmental factors **12. What factor does NOT influence the classification of a disease as epidemic?** a\) Geographical isolation\ b) Mode of transmission\ c) Change in host susceptibility\ d) Environmental disruption **Answer:** a) Geographical isolation **13. Which disease pattern typically leads to localized outbreaks but occurs in unpredictable locations?** a\) Endemic\ b) Pandemic\ c) Sporadic\ d) Epidemic **Answer:** c) Sporadic **14. A disease affecting multiple countries and a large proportion of the population is classified as:** a\) Sporadic\ b) Pandemic\ c) Epidemic\ d) Hyperendemic **Answer:** b) Pandemic **15. Which of the following does NOT represent an environmental factor influencing disease spread?** a\) Temperature fluctuations\ b) Breed-specific susceptibility\ c) Humidity levels\ d) Animal management practices **Answer:** b) Breed-specific susceptibility **16. Which term refers to an epidemic that affects only a small number of animals but occurs more frequently than expected?** a\) Endemic\ b) Sporadic\ c) Epidemic\ d) Hyperendemic **Answer:** d) Hyperendemic **17. The introduction of a susceptible group of animals into an infected area will most likely lead to:** a\) A sporadic occurrence\ b) An endemic level of disease\ c) An epidemic\ d) A pandemic **Answer:** c) An epidemic **18. Which disease classification would apply to a global outbreak affecting humans and animals?** a\) Endemic\ b) Sporadic\ c) Pandemic\ d) Hyperendemic **Answer:** c) Pandemic **19. What is the usual outcome once the susceptible population is exhausted during an epidemic?** a\) Cases increase further\ b) The disease becomes pandemic\ c) The number of cases declines\ d) The disease becomes endemic **Answer:** c) The number of cases declines **20. When does a disease become classified as notifiable under the OIE?** a\) When it causes a pandemic\ b) When it has zoonotic potential\ c) When it causes sporadic outbreaks\ d) When it is identified in three or more countries **Answer:** b) When it has zoonotic potential **1. What is an epidemic curve?** A. A graph showing animal density in an area\ B. A curve that represents the geographical distribution of disease\ C. A graph that represents the temporal distribution pattern of disease\ D. A graph that only shows the number of deaths caused by a disease\ **Answer: C** **2. Which factor primarily affects the slope of the ascending branch of an epidemic curve?** A. Number of index cases\ B. Infectivity of the agent\ C. Duration of the infectious period\ D. Herd immunity levels\ **Answer: B** **3. What does a secondary peak in an epidemic curve typically indicate?** A. Introduction of susceptible animals into the epidemic area\ B. End of the epidemic\ C. The highest number of cases recorded\ D. Immunization of the population\ **Answer: A** **4. What is Kendall\'s Threshold Theorem?** A. A formula predicting how rapidly an epidemic will progress\ B. A principle that explains the threshold level of susceptible animals for an epidemic\ C. A theorem for calculating vaccination efficiency\ D. A method for estimating the reproduction number of a disease\ **Answer: B** **5. What is the basic reproduction number (R0)?** A. The number of cases required to declare an outbreak\ B. The expected number of secondary infections from a single infection\ C. The time it takes for an infection to spread\ D. The speed at which symptoms appear after exposure\ **Answer: B** **6. If the R0 of a disease is less than 1, what does this indicate?** A. The disease will lead to a massive epidemic\ B. The disease will remain stable within the population\ C. The disease will gradually die out\ D. The disease will increase over time\ **Answer: C** **7. What type of epidemic occurs when cases serve as the source of infection for subsequent cases?** A. Common source epidemic\ B. Propagated epidemic\ C. Continuous source epidemic\ D. Cyclical epidemic\ **Answer: B** **8. In the case of a common source epidemic, what is typically observed?** A. Continuous generation of new cases over time\ B. A single peak in the epidemic curve\ C. Successive waves of infection\ D. No discernable pattern in the epidemic curve\ **Answer: B** **9. Seasonal trends in disease patterns are primarily associated with what factor?** A. Changes in host population density\ B. Climatic or environmental changes\ C. Random fluctuations in animal behavior\ D. The initial introduction of a pathogen\ **Answer: B** **10. What is the shape of the curve in a propagated epidemic?** A. A single sharp peak followed by a decline\ B. Multiple peaks reflecting successive generations of cases\ C. A flat plateau indicating steady infection rates\ D. A downward curve with no peaks\ **Answer: B** **11. What are the two key factors that can help flatten the curve during a pandemic?** A. Quarantine and vaccination\ B. Surveillance and diagnosis\ C. Travel restrictions and improved sanitation\ D. Social distancing and herd immunity\ **Answer: D** **12. What differentiates cyclical trends from secular trends in disease occurrence?** A. Secular trends are short-term, cyclical trends are long-term\ B. Cyclical trends involve periodic fluctuations, secular trends are long-term changes\ C. Secular trends are more common in seasonal diseases\ D. Cyclical trends are due to sudden disease outbreaks\ **Answer: B** **13. What typically characterizes a short-term temporal distribution of disease?** A. A gradual increase in cases over decades\ B. A sharp peak followed by a gradual decline\ C. Stable disease levels with no significant changes\ D. Fluctuations in cases over several years\ **Answer: B** **14. How does herd immunity affect the descending branch of an epidemic curve?** A. It causes the curve to descend more gradually\ B. It prolongs the plateau phase of the curve\ C. It steepens the slope of the descending branch\ D. It has no effect on the shape of the curve\ **Answer: C** **15. What factor does Kendall's Threshold Theorem primarily focus on?** A. The probability of an infected animal infecting others\ B. The length of the infectious period\ C. The population size needed for an epidemic to spread\ D. The severity of symptoms in the host\ **Answer: C** **16. Which of the following is NOT a factor that affects the basic reproduction number (R0)?** A. Duration of infectiousness\ B. Contact rate between animals\ C. Population size of infected animals\ D. Probability of infection transmission per contact\ **Answer: C** **17. Which type of epidemic curve shows a sudden rise and fall due to a single exposure to a source of infection?** A. Point source epidemic\ B. Propagated epidemic\ C. Continuous source epidemic\ D. Cyclical epidemic\ **Answer: A** **18. What is a key feature of a continuous common source epidemic?** A. A single, short peak in the epidemic curve\ B. Intermittent peaks of infection\ C. A rise followed by a gradual decline over time\ D. Multiple waves of infection following a common exposure\ **Answer: C** **19. What can cause a propagated epidemic to wane?** A. The introduction of new susceptible animals\ B. Intervention measures like vaccination\ C. A sudden increase in herd immunity\ D. All of the above\ **Answer: B** **20. Which of the following best describes the cyclical trend in disease distribution?** A. A continuous, predictable rise in cases\ B. Fluctuations in disease cases due to changes in host and environmental factors\ C. A rapid increase in cases over a short time frame\ D. An unpredictable pattern with no clear periodicity\ **Answer: B** **1.** In a farm with an outbreak of Newcastle disease, workers report that some animals in a distant pen, isolated from direct contact with infected birds, have started showing symptoms. Given that the workers wear gloves but do not change them between pens, which type of transmission is most likely responsible for spreading the disease?\ A. Vertical transmission\ B. Vector-borne transmission\ C. Fomite transmission\ D. Airborne transmission\ **Answer:** C. Fomite transmission **2.** A farm experiences an African Swine Fever outbreak, but despite biosecurity measures, the disease continues to spread. You note that several wild boars were seen near the farm, but no direct contact with pigs was observed. What type of transmission could explain the continued spread of the disease?\ A. Vertical transmission\ B. Indirect horizontal transmission\ C. Vertical transmission via placenta\ D. Direct horizontal transmission\ **Answer:** B. Indirect horizontal transmission **3.** In a poultry farm, a hen infected with Avian Influenza lays eggs, which are then incubated. Chicks hatched from these eggs are also found to be infected. This is an example of:\ A. Horizontal transmission through contact\ B. Vertical transmission via transovarial route\ C. Vector-borne transmission\ D. Horizontal transmission through contaminated feed\ **Answer:** B. Vertical transmission via transovarial route **4.** A veterinarian is investigating a case where calves are consistently born with a viral infection. Their mothers are symptom-free but have been exposed to infected bulls. Which type of transmission most likely explains the infection in the calves?\ A. Horizontal transmission via contact with contaminated tools\ B. Vertical transmission from mother to offspring\ C. Horizontal transmission via direct contact between animals\ D. Vector-borne transmission\ **Answer:** B. Vertical transmission from mother to offspring **5.** In a rabies outbreak, a local community vaccinates its dogs, reducing new cases over the next few months. However, some dogs are still getting infected, mainly those with wounds. Which route of transmission is most likely responsible for these cases?\ A. Vertical transmission\ B. Horizontal transmission via bite wounds\ C. Fomite transmission\ D. Airborne transmission\ **Answer:** B. Horizontal transmission via bite wounds **6.** A farmer notices that sheep in one part of the pasture are infected with Bluetongue. Several days later, sheep in another area, far from the initial infection, show signs of the disease. What is the most likely route of transmission?\ A. Vertical transmission through infected lambs\ B. Horizontal transmission through direct contact\ C. Vector-borne transmission via biting midges\ D. Fomite transmission from farm tools\ **Answer:** C. Vector-borne transmission via biting midges **7.** A breeding program for cattle experiences an outbreak of Brucellosis. The bulls are tested and found to be Brucella positive, although they do not show signs of illness. How did the disease most likely spread to the calves?\ A. Vertical transmission via infected semen\ B. Horizontal transmission via waterborne spread\ C. Horizontal transmission via vectors\ D. Vertical transmission via trans-stadial transfer\ **Answer:** A. Vertical transmission via infected semen **8.** In a farm housing both chickens and turkeys, Highly Pathogenic Avian Influenza (HPAI) breaks out in the chickens. Despite stringent biosecurity, the turkeys in a separate barn also become infected. Which method of disease spread is most likely?\ A. Horizontal transmission via shared ventilation\ B. Vertical transmission\ C. Fomite transmission through feed trucks\ D. Airborne transmission between the barns\ **Answer:** A. Horizontal transmission via shared ventilation **9.** During an investigation of a Swine Flu outbreak, it is discovered that pigs on separate farms have become infected, though no direct contact between animals occurred. The farms share a common water source. What is the most likely route of transmission?\ A. Vertical transmission through gestation\ B. Fomite transmission via shared equipment\ C. Horizontal transmission via waterborne spread\ D. Airborne transmission\ **Answer:** C. Horizontal transmission via waterborne spread **10.** In a farm where Japanese encephalitis is present, pigs show neurological symptoms. Pigs are housed near rice fields known to harbor mosquitoes. What type of transmission is most likely responsible for spreading the virus among pigs?\ A. Horizontal transmission via close contact\ B. Vector-borne transmission via mosquitoes\ C. Vertical transmission through pregnant sows\ D. Fomite transmission via contaminated tools\ **Answer:** B. Vector-borne transmission via mosquitoes **11.** A flock of chickens becomes infected with Infectious Bursal Disease (Gumboro Disease). Despite separation from infected birds, younger chickens, housed in a nearby barn, start showing signs. The workers handling feed are not following proper sanitation procedures. What is the likely mode of transmission?\ A. Horizontal transmission via aerosol droplets\ B. Fomite transmission via contaminated feed\ C. Vertical transmission\ D. Vector-borne transmission\ **Answer:** B. Fomite transmission via contaminated feed **12.** A cattle herd experiences an outbreak of Surra (Trypanosoma evansi). Investigations reveal that the disease appeared shortly after animals were moved from a region with a high density of biting flies. What is the most likely mode of transmission?\ A. Horizontal transmission via close contact\ B. Vector-borne transmission via biting flies\ C. Vertical transmission through gestation\ D. Airborne transmission\ **Answer:** B. Vector-borne transmission via biting flies **13.** In an outbreak of Classical Swine Fever, new cases emerge days after initial control measures. The new cases are found in an area downwind of the infected herd. What transmission method does this suggest?\ A. Airborne horizontal transmission\ B. Vertical transmission from infected sows\ C. Fomite transmission through farm vehicles\ D. Vector-borne transmission\ **Answer:** A. Airborne horizontal transmission **14.** A disease with a basic reproduction number (R0) greater than 1 is spreading rapidly through a population of animals. What is the most likely outcome if no interventions are taken?\ A. The disease will decline and die out\ B. The disease will remain stable without an outbreak\ C. The disease will cause an outbreak or epidemic\ D. The disease will stay alive but not spread further\ **Answer:** C. The disease will cause an outbreak or epidemic **15.** In a flock of chickens infected with Pullorum disease, infected hens are found to pass the disease to their offspring during hatching. This type of transmission is best described as:\ A. Horizontal transmission\ B. Vector-borne transmission\ C. Vertical transmission\ D. Fomite transmission\ **Answer:** C. Vertical transmission **16.** During a rabies outbreak, a local vaccination campaign reduces the number of new cases among pets. However, wild animals continue to transmit the disease. What is the most likely method of disease spread in wild animals?\ A. Vertical transmission via gestation\ B. Horizontal transmission via direct bites\ C. Fomite transmission via contaminated food\ D. Airborne transmission\ **Answer:** B. Horizontal transmission via direct bites **17.** A poultry farm experiences an outbreak of Highly Pathogenic Avian Influenza. Despite cleaning and disinfection, new cases arise. Tracing back, it is discovered that a water delivery truck had visited multiple infected farms. This points to which type of transmission?\ A. Horizontal transmission via contaminated water\ B. Vertical transmission\ C. Vector-borne transmission\ D. Horizontal transmission via fomites\ **Answer:** D. Horizontal transmission via fomites **18.** During a Brucella abortus outbreak, cattle on two neighboring farms become infected despite no direct animal contact. The farms share a veterinarian who uses the same equipment for examining both herds. What type of transmission does this scenario suggest?\ A. Horizontal transmission via direct contact\ B. Vertical transmission\ C. Fomite transmission via contaminated equipment\ D. Airborne transmission\ **Answer:** C. Fomite transmission via contaminated equipment **19.** A study shows that trichinellosis in pigs often occurs after pigs consume contaminated food sources. What is the most likely mode of transmission in this case?\ A. Vertical transmission\ B. Horizontal transmission via ingestion\ C. Vector-borne transmission\ D. Airborne transmission\ **Answer:** B. Horizontal transmission via ingestion **20.** A herd of cattle is affected by a propagating epidemic, where each case infects subsequent animals, leading to multiple waves of new cases. What type of epidemic does this describe?\ A. Point-source epidemic\ B. Common-source epidemic\ C. Continuous-source epidemic\ D. Propagated epidemic\ **Answer:** D. Propagated epidemic