COMMUNITY MEDICINE IMPORTANT MCQS
GENERAL EPIDEMIOLOGY
1. While investigating a point source epidemic it was found that 120 students ate five different
foods (meat burgers, fried fish, steak, and rice and fruit salad. The relative risk was calculated for
all those five foods. It was concluded that fish was not responsible for this epidemic. The relative
risk of fish is:
a) 0.7 d) 3.0
b) 1.2 e) 7.0
c) 1.7
Key: True: a
2.In a prospective study of the relationship between oral contraceptive use and the subsequent
risk of developing endometrial cancer, a cohort of 1000 women were followed for 5 years. The
results were as follows:
Present Absent
A 245
B 75
C 50
D 630
A + C = 295 B + D = 705 n = 1000
3. What is the incidence rate (absolute risk) of endometrial cancer among who didn’t use oral
contraceptives?
a) 630 / (50 + 630) d) 245 / (245 + 75)
b) 75 / (245 + 75) e) Insufficient data
c) 50 / (50 + 630)
Key: True: c 50/ (50 + 630)
4. In a prospective study of the relationship between oral contraceptive use and the subsequent
risk of developing endometrial cancer, a cohort of 1000 women were followed for 5 years. The
results were as follows:
Present Absent
,A 245
B 75
C 50
D 630
A + C = 295 B + D = 705 n = 1000
4. What is the incidence rate (absolute risk) of endometrial cancer among women who used oral
contraceptives in person-years? If the study was carried out for five years.
a) 630 / (680 x 5) d) 75 / (320 + 5)
b) 75 / (320 x 5) e) 245 / (320 x 5
c) 50 / (630 x 5)
Key: True: e 245 / (320 x 5)
5. In a prospective study of the relationship between oral contraceptive use and the subsequent
risk of developing endometrial cancer, a cohort of 1000 women were followed for 5 years. The
results were as follows:
Present Absent
A 245
B 75
C 50
D 630
A + C = 295 B + D = 705 n = 1000
What is the relative risk in this study?
a) [75 / (245 + 75)] / [50 / (50 + 630)]
b) [75 / (245 + 75)] / [630 / (50 + 630)]
c) [50 / (245 + 50)] / [630 / (75 + 630)]
d) [245 / (245 + 75)] / [50 / (50 + 630)]
e) Insufficient data
Key: True: d [245 / (245 + 75)] / [50 / (50 + 630)]
,6. Among 10 women with cervical cancer, medical records confirm a past history of herpes
simplex type II infection in eight. What is the relative risk of developing cervical cancer in women
with a history of HSV type II infection?
a) 8/10 d) 2/10
b) 10/8 e) 2/8
c) 8/2
Key: True: c
7. In an outbreak of cholera in a village of 2,000 population, 20 cases have occurred and 5 die
Case fatality rate is:
a) 1% d) 25%
b) .25% e) .0025%
c) 5%
Key: True: d
Questions # 8-9.
The results of a study of the incidence of pulmonary tuberculosis in a village in India are given in
the table below. All persons in the village are examined during two surveys made 2 years apart,
and the number of new cases was used to determine the incidence rat
Category of Household at First survey
Number of Persons
Number of New cases
With culture positive case
500
10
Without culture positive case
10,000
10
8. What is the incidence of new cases per 1000 person years in households that had a culture
positive case during the first survey?
a) 0.02 b) 0.01
, c) 1.0 e) 20
d) 10
Key: True: d
10 new cases = 10 cases/1000 persons years
500 persons x 2 years
9. What is the incidence of new cases per 1000 person years in households that did not have a
culture positive case during the first survey?
a) 0.001 d) 1.0
b) 0.1 e) 5.0
c) 0.5
Key: True: c
10 new cases = 0.5 cases/1000 persons years
10,000 persons x 2 years
10. In a population of 1000, measles coverage is 60%, one child goes out of station and comes
back with measles from whom 20 more children get measles. Secondary attack rate of measles
is:
a) 0.65% d) 6.5%
b) 5% e) 7%
c) 6%
Key: True: b
11. A village has total of 100 under-five children. The coverage with measles vaccine in this age
group is 60%. Following the occurrence of a measles case in a child after a visit outside, twenty-
six children developed measles. The secondary attack rate of measles is:
a) 25% d) 65%
b) 40% e) 66%
c) 50%
Key: True: e
12. If an epidemiologist while investigating an epidemic makes a graph to plot distribution of
cases of disease by the time of onset and gets a polymodal distribution curv The most likely
disease is:
a) Salmonellosis b) Staphylococcal food poisoning
GENERAL EPIDEMIOLOGY
1. While investigating a point source epidemic it was found that 120 students ate five different
foods (meat burgers, fried fish, steak, and rice and fruit salad. The relative risk was calculated for
all those five foods. It was concluded that fish was not responsible for this epidemic. The relative
risk of fish is:
a) 0.7 d) 3.0
b) 1.2 e) 7.0
c) 1.7
Key: True: a
2.In a prospective study of the relationship between oral contraceptive use and the subsequent
risk of developing endometrial cancer, a cohort of 1000 women were followed for 5 years. The
results were as follows:
Present Absent
A 245
B 75
C 50
D 630
A + C = 295 B + D = 705 n = 1000
3. What is the incidence rate (absolute risk) of endometrial cancer among who didn’t use oral
contraceptives?
a) 630 / (50 + 630) d) 245 / (245 + 75)
b) 75 / (245 + 75) e) Insufficient data
c) 50 / (50 + 630)
Key: True: c 50/ (50 + 630)
4. In a prospective study of the relationship between oral contraceptive use and the subsequent
risk of developing endometrial cancer, a cohort of 1000 women were followed for 5 years. The
results were as follows:
Present Absent
,A 245
B 75
C 50
D 630
A + C = 295 B + D = 705 n = 1000
4. What is the incidence rate (absolute risk) of endometrial cancer among women who used oral
contraceptives in person-years? If the study was carried out for five years.
a) 630 / (680 x 5) d) 75 / (320 + 5)
b) 75 / (320 x 5) e) 245 / (320 x 5
c) 50 / (630 x 5)
Key: True: e 245 / (320 x 5)
5. In a prospective study of the relationship between oral contraceptive use and the subsequent
risk of developing endometrial cancer, a cohort of 1000 women were followed for 5 years. The
results were as follows:
Present Absent
A 245
B 75
C 50
D 630
A + C = 295 B + D = 705 n = 1000
What is the relative risk in this study?
a) [75 / (245 + 75)] / [50 / (50 + 630)]
b) [75 / (245 + 75)] / [630 / (50 + 630)]
c) [50 / (245 + 50)] / [630 / (75 + 630)]
d) [245 / (245 + 75)] / [50 / (50 + 630)]
e) Insufficient data
Key: True: d [245 / (245 + 75)] / [50 / (50 + 630)]
,6. Among 10 women with cervical cancer, medical records confirm a past history of herpes
simplex type II infection in eight. What is the relative risk of developing cervical cancer in women
with a history of HSV type II infection?
a) 8/10 d) 2/10
b) 10/8 e) 2/8
c) 8/2
Key: True: c
7. In an outbreak of cholera in a village of 2,000 population, 20 cases have occurred and 5 die
Case fatality rate is:
a) 1% d) 25%
b) .25% e) .0025%
c) 5%
Key: True: d
Questions # 8-9.
The results of a study of the incidence of pulmonary tuberculosis in a village in India are given in
the table below. All persons in the village are examined during two surveys made 2 years apart,
and the number of new cases was used to determine the incidence rat
Category of Household at First survey
Number of Persons
Number of New cases
With culture positive case
500
10
Without culture positive case
10,000
10
8. What is the incidence of new cases per 1000 person years in households that had a culture
positive case during the first survey?
a) 0.02 b) 0.01
, c) 1.0 e) 20
d) 10
Key: True: d
10 new cases = 10 cases/1000 persons years
500 persons x 2 years
9. What is the incidence of new cases per 1000 person years in households that did not have a
culture positive case during the first survey?
a) 0.001 d) 1.0
b) 0.1 e) 5.0
c) 0.5
Key: True: c
10 new cases = 0.5 cases/1000 persons years
10,000 persons x 2 years
10. In a population of 1000, measles coverage is 60%, one child goes out of station and comes
back with measles from whom 20 more children get measles. Secondary attack rate of measles
is:
a) 0.65% d) 6.5%
b) 5% e) 7%
c) 6%
Key: True: b
11. A village has total of 100 under-five children. The coverage with measles vaccine in this age
group is 60%. Following the occurrence of a measles case in a child after a visit outside, twenty-
six children developed measles. The secondary attack rate of measles is:
a) 25% d) 65%
b) 40% e) 66%
c) 50%
Key: True: e
12. If an epidemiologist while investigating an epidemic makes a graph to plot distribution of
cases of disease by the time of onset and gets a polymodal distribution curv The most likely
disease is:
a) Salmonellosis b) Staphylococcal food poisoning
