AIIMS/ NEET-PG 2017 Community Medicine MCQs 1-10

Q-1. Leprosy involves all except
a) Uterus
b) Ovary
c) Nerve
d) Eye

Answer: Uterus
Explanation:
Leprosy lesions involve the cooler body tissues: Skin, superficial nerves, nose, pharynx, larynx, eyes and testicles.
Female genital tract is very rarely involved and if there is any involvement, ovary is the most common genital organ to be involved.

Q-2. True about global warming is
a) CO2 is the major greenhouse gas
b) Stratosphere ozone layer is harmful
c) CFC increases stratosphere ozone layer
d) Kyoto protocol called for 20% reduction in green house effect

Answer: CO2 is the major greenhouse gas
Explanation:
Green house gases:
Water vapor
Co2
Methane
Nitrous oxide
Ozone
Chlorofluorocarbons (CFCs), hydro-fluorocarbons (HFCs) and Per-fluorocarbons (PFCs), as well as sulfur hexafluoride (SF6).
CFC decreases stratosphere ozone layer

Q-3. Incidence can be calculated by
a) Case-control study
b) Prospective study
c) Retrospective study l
d) Cross-sectional study

Answer: Prospective study
Explanation:
Cohort study:
It is also known as prospective study, longitudinal study, incidence study and forward looking study.
Advantages:
Incidence can be calculated.
Several possible outcomes related to exposure can be studied simultaneously.
It provides a direct estimate of relative risk.
Dose response ration can also be calculated.

Q-4. All are true about Aedes except
a) Bites repeatedly
b) Eggs cannot survive for more than a week without water
c) Transmits dengue
d) It takes 7-8 days to develop the parasite and transmit the disease

Answer: Eggs cannot survive for more than a week without water
Explanation:
Aedes can use natural locations or habitats (for example tree-holes and plant axils) and artificial containers with water to lay their eggs.
Eggs are resistant to desiccation and can survive for periods of six or more months.
When rain floods the eggs with water, the larvae hatch. Aedes bite repeatedly.
Within the mosquito, the virus infects the mosquito mid-gut and subsequently spreads to the salivary glands over a period of 8-12 days.
After this incubation period, the virus can be transmitted to humans during subsequent probing or feeding.
Aedes born diseases:
Dengue
Dengue hemorrhagic fever
Chikungunya fever
Chikungunya hemorrhagic fever
Rift valley fever
Yellow fever and filaria (Not in India)

Q-5. All of the following statements about purification of water are true except
a) Presence of Clostridial spores indicate recent contamination of water
b) Coliforms must not be detectable in any 100 ml sample of drinking water
c) Sodium thiosulphate is used to neutralize chlorine
d) Coliforms may be detected by multiple tube method & indole production

Answer: Presence of Clostridial spores indicate recent contamination of water
Explanation:
The presence of spores of Cl perfringens in natural water suggests that fecal contamination has occurred and their presence in absence of the coli-form group, suggests that fecal contamination occurred at some remote time.
All water intended for drinking, E. coli or thermo-tolerant coli-form bacteria must not be detectable in any 100 ml sample.

Q-6. Not seen in fecal pollution
a) Staphylococcus
b) Streptococcus
c) E. coli
d) Clostridium perfringens

Answer: Staphylococcus
Explanation:
Bacterial indicators of fecal pollution:
Primary:
Coli-form organisms
Supplementary:
Fecal streptococci
Clostridium perfringens

Q-7. Vitamin A prophylaxis to a child is
a) Health promotion
b) Specific protection
c) Primordial prevention
d) Secondary prevention

Answer: Specific protection
Explanation:
Specific protection:
To avoid disease altogether is the ideal but this possible only in limited number of cases.
Currently available interventions:
Immunization
Use of specific nutrients
Chemoprophylaxis
Protection against occupational hazards and accidents
Protection from carcinogens
Avoidance of allergens

Q-8. Savlon contains
a) Cetrimide + Chlorhexidine
b) Cetrimide + Chlorhexidine + butyl alcohol
c) Cetrimide + Butyl alcohol
d) Cetrimide + Cetavlon

Answer: Cetrimide + Chlorhexidine
Explanation:
Savlon is an antiseptic containing the two agents, Cetrimide, an antimicrobial detergent, and Chlorhexidine gluconate.

Q-9. Not true about crude birth rate
a) It is a measure of fertility
b) It is actually a ratio not rate
c) It is independent of age of population
d) Numerator does not include still births

Answer: It is actually a ratio not rate
Explanation:
Crude birth rate = Number of live birth during the year/estimated mid-year population x 100
It is the simplest measure of fertility.
General fertility ratio (GFR) is a better measure of fertility than crude birth rate as it includes female population of 15-44 years age group as denominator.

Q-10. Direct standardization is used to compare the mortality rates between two countries this a done because of the differences in
a) Causes of death
b) Numerators
c) Age distributions
d) Denominators

Answer: Age distributions
Explanation:
Methods of Standardization:
There are two methods of standardization commonly used in epidemiological studies, and these are characterized by whether the standard used is a population distribution (direct method) or a set of specific rates (indirect method).
Age is a factor that is frequently adjusted for in epidemiological investigations, particularly in comparative mortality studies, since the age structure of a population will greatly affect the population’s overall mortality.