Epidemiology and Public Health MCQs
1) Venereal transmission of disease in a flock occurs through
a) Injection
b) Ingestion
c) Sexual interaction d) Doctors
Correct Answer: c) Sexual interaction
Explanation: Venereal transmission refers to the spread of infectious agents through sexual interaction between animals. In poultry, this typically involves the transfer of pathogens during mating, which can lead to infertility or systemic infection.
2) The haemagglutinin is an antigenic determinant present on
a) Pappiloma virus
b) IBD virus
c) NDV d) Adeno virus
Correct Answer: c) NDV
Explanation: Newcastle Disease Virus (NDV) possesses haemagglutinin-neuraminidase (HN) proteins on its envelope. These spikes allow the virus to bind to sialic acid receptors on host cells and agglutinate red blood cells, a property used in the Hemagglutination (HA) diagnostic test.
3) The IB virus preferably infects which organ(s)?
a) Respiratory & reproductive b) CNS & GIT
c) Heart
d) Liver
Correct Answer: a) Respiratory & reproductive
Explanation: Infectious Bronchitis (IB) virus is a coronavirus that primarily targets the respiratory tract (causing gasping and coughing) and the reproductive tract (leading to a drop in egg production and “watery whites” in eggs).
4) Infectious diseases can spread from farm to farm through inanimate objects called as
a) Reservoirs
b) Carriors
c) Fomites d) Machines
Correct Answer: c) Fomites
Explanation: Fomites are any non-living (inanimate) objects, such as contaminated footwear, clothing, egg crates, or vehicle tires, that can carry and transmit infectious pathogens from one location to another.
5) Which of the following disease is transmitted from parrots to human?
a) Typhoid
b) Bird flu
c) Psittacosis d) Cholera
Correct Answer: c) Psittacosis
Explanation: Psittacosis (also known as Parrot Fever) is caused by the bacterium Chlamydia psittaci. It is a zoonotic disease typically transmitted to humans through the inhalation of dried bird droppings or respiratory secretions from infected parrots or other pet birds.
6) Presence of maternal antibodies_____________ the effect of vaccines
a) Antagonise b) Enhance
c) Synergize
d) Complement
Correct Answer: a) Antagonise
Explanation: High levels of maternally derived antibodies (MDA) can antagonise or interfere with the efficacy of live vaccines. They neutralize the vaccine virus before it can stimulate the chick’s own immune system, necessitating proper “timing” for the first vaccination.
7) Which of the following is a viral zoonotic disease of poultry?
a) IBD
b) HPS
c) Bird Flu d) CIA
Correct Answer: c) Bird Flu
Explanation: Bird Flu (Avian Influenza) is a highly contagious viral disease. Certain strains (like H5N1 or H7N9) are zoonotic, meaning they can jump from birds to humans, posing a significant public health risk.
8) The occasional occurrence of a disease in a population is called as
a) Epidemic
b) Outbreak
c) Pandemic
d) Sporadic
Correct Answer: d) Sporadic
Explanation: A disease is described as sporadic when it occurs only occasionally, at irregular intervals, and in scattered instances without a predictable pattern in a population.
9) In cohort epidemiological studies, the word “cohort” means
a) Population
b) Group c) Risk
d) Variable
Correct Answer: b) Group
Explanation: In epidemiology, a cohort refers to a well-defined group of individuals who share a common characteristic or experience (like exposure to a specific risk factor) and are followed over time to observe the outcome.
10) Which of the following is an arthropod vector borne disease of chicken?
a) Avian Influenza
b) Coccidiosis
c) Spirochetosis d) CRD
Correct Answer: c) Spirochetosis
Explanation: Spirochetosis (caused by Borrelia anserina) is a common septicaemic disease of poultry transmitted by the soft tick (Argas persicus), which acts as the arthropod vector.
11) Which of the following is not an immuno-diagnostic test?
a) PCR b) HA & HI
c) ELISA
d) Serum plate agglutination test
Correct Answer: a) PCR
Explanation: Polymerase Chain Reaction (PCR) is a molecular diagnostic test that detects the genetic material (DNA/RNA) of a pathogen. The others (ELISA, HI, SPA) are immuno-diagnostic because they rely on antigen-antibody reactions.
12) In case of stable endemic diseases, the prevalence equals to
a) C x I
b) I x D c) P x D
d) none of above
Correct Answer: b) I x D
Explanation: In a stable population, the Prevalence (P) of a disease is equal to the Incidence (I) multiplied by the average Duration (D) of the disease ($P = I \times D$).
13) Which of the following is an example of hydatid cyst zoonosis?
a) Saprozoonosis
b) Reverse zoonosis
c) Cyclozoonosis d) all of the above
Correct Answer: c) Cyclozoonosis
Explanation: Hydatid disease is a cyclozoonosis because the parasite (Echinococcus granulosus) requires more than one vertebrate host species (e.g., dog and sheep) to complete its life cycle.
14) Which of the followings are included in intrinsic determinants of a disease
a) Specie
b) Environment
c) Genetics
d) A & C
Correct Answer: d) A & C
Explanation: Intrinsic determinants (host factors) are internal to the animal, such as Species, Genetics, age, and sex. The environment is considered an extrinsic (external) determinant.
15) Sudden outbreak of a disease in avian population is called as
a) Epidemic
b) Pandemic
c) Epornitics d) Sporadic
Correct Answer: c) Epornitics
Explanation: The term epornitic is the avian equivalent of an “epidemic.” it refers to a sudden, widespread outbreak of an infectious disease within a bird population.
16) The exposed and non-exposed groups are compared for the causation of a disease in which studies?
a) Case-control
b) Experimental c) Cross-sectional
d) non of the above
Correct Answer: b) Experimental
Explanation: In experimental (or cohort) studies, researchers compare groups based on their exposure status to determine if that exposure causes a specific disease or outcome.
17) For disease forecasting, which of the following system is currently used in epidemiology
a) Topogarphy
b) GIS c) Computer & IT
d) Mobile & cable
Correct Answer: b) GIS
Explanation: Geographic Information Systems (GIS) are powerful tools used for mapping and forecasting disease trends by analyzing spatial data and environmental risk factors.
18) Lack of _____________ of a diagnostic test results in false positive results
a) Specificity b) Predictive value
c) Sensitivity
d) Reproducibity
Correct Answer: a) Specificity
Explanation: Specificity is the ability of a test to correctly identify healthy animals. A test with low specificity will yield a high number of false positives because it may react to other similar substances or organisms.
19) The nosocomial infections are acquired from
a) Plants
b) Hospital c) Animals
d) Doctors
Correct Answer: b) Hospital
Explanation: Nosocomial infections (also called healthcare-associated infections) are those acquired during a stay in a hospital or clinical setting that were not present at the time of admission.
20) Area based distribuation of a disease is reffered as
a) Temporal
b) Concomitant
c) Sporadic
d) Spatial
Correct Answer: d) Spatial
Explanation: Spatial distribution refers to how a disease is spread across a geographic area or location. Temporal distribution refers to changes over time.
21) Amount or magnitude of a disease in a population is called as
a) % positivity
b) Occurrence c) Hyperendemic
d) none of the above
Correct Answer: b) Occurrence
Explanation: Occurrence is a general term describing the frequency or magnitude of a disease in a population, often measured through incidence or prevalence rates.
22) Making routine observations on health, productivity and environment is called as
a) GIS
b) Monitoring c) Surveillence d) Cohort studies
Correct Answer: b) Monitoring
Explanation: Monitoring involves the routine, continuous observation and recording of health and productivity data. Surveillance is more active and usually involves taking action when a specific threshold is met.
23) Trans-stadial transmission of disease is mostly observed in
a) Viral diseases
b) Protozoan diseases c) Bacterial diseases
d) Cancer
Correct Answer: b) Protozoan diseases
Explanation: Trans-stadial transmission occurs when a pathogen (commonly a protozoan like Theileria or Babesia) survives through the different life stages of an arthropod vector, such as from a tick larva to a nymph.
24) Mortality of a disease can be calculated as
a) no. of deaths/total population b) no. of diseased animals/total population
c) M=I/D
d) none of the above
Correct Answer: a) no. of deaths/total population
Explanation: The mortality rate is calculated by dividing the number of deaths due to a disease by the total population at risk during a specific period.
25) Dengue fever is a
a) Arbo-viral disease b) Protozoan disease
c) Oncoviral disease
d) Water-borne disease
Correct Answer: a) Arbo-viral disease
Explanation: Dengue is an arbo-viral (arthropod-borne viral) disease, meaning it is caused by a virus transmitted to humans through the bite of infected mosquitoes, primarily Aedes aegypti.