1) WHO declared global eradication of small pox on-
A. 26th October 1997
B. 5th July 1975
C. 17th May 1975
D. 8th May 1980
Ans. :- (d) 8th May 1980 [Ref: 23rd /e p. 143]
Exp.: - The WHO declared on 8th may 1980 that smallpox had been eradicated.
2) The last case of small pox was reported in the world
A. 1997
B. 1978
C.1979
D. 1982
Ans. :- (a) 1997 [Ref: 23rd /e p. 143]
Exp.: - The world’s last case of smallpox occurred in Somalia on 26 October 1977 (Apart from laboratory accident in 1978).
3) Small pox eradication was successful because of all except-
A. Subclinical cases don’t transmit disease
B. Highly effective vaccine
C. Lifelong immunity
D. Cross resistance with animal pox
Ans.:- (d) Cross resistance with animal pox [Ref: 23rd /e p. 143]
Exp.:- Small pox eradication – Epidemiological basis
No known animal reservoir
No long – term carrier of the virus.
Life – long immunity after recovery from the disease.
The detection of cases comparatively simple because the rash was so characteristic and occurred in visible parts of the body.
Persons with sub-clinical infection did not transmit the disease.
Vaccine is highly effective; easily administered, heat stable and confers long – term protection.
International cooperation.
4) Which of the following factors helped in smallpox eradication?
A. Short incubation period of disease
B. Slow evolution of rashes over body
C. Long-term carrier stages in patients
D. Life-long immunity after disease
Ans.:- (d) Life-long immunity after disease [Ref: 23rd /e p. 142]
5) The infectivity of chicken pox lasts for-
A. Till the last scab falls off
B. 6 days after onset of rash
C. 3 days after onset of rash
D. Till the fever subsides
Ans.:- (b) 6 days after onset of rash [Ref: 23rd /e p. 144]
Exp.:- infectious period of chicken pox: - 2 days before and 5 days after the onset of rash.
6) Rash of chickenpox can be differentiated from the rash of small pox by the all except-
A. Pleomorphic
B. Centripetal
C. Deep-seated
D. Unilocular
Ans.:- (c) Deep- seated [Ref: 23rd /e p. 144]
Exp.:- Rash of chickenpox is superficial (not deep seated).
:- Rash of chicken pox : Superficial, unilocular, centripetal, pleomorphic, symmetrical, affects flexor surfaces and axilla, spares palms and sales, has inflammation around, rapid evolution and dew-drop on rose petal appearance.
7) All of the following are characteristics of the chicken pox rash except-
A. Rash occurs in crops
B. Pleomorphism is present
C. Is centripetal in distribution
D. Scab are infectious
Ans.:- (d) Scab are infectious [Ref: 23rd /e p. 144]
Exp.:- The fluid of vesicle of chickenpox contains virus during first 3 days of illness, but scab is non-infective.
8) Secondary attack rate of chicken pox is-
A. 60
B. 50
C. 90
D. 40
Ans.:- (c) 90 [Ref: 23rd /e p. 144]
Exp.:- Secondary attack rate of chicken pox is high, up-to 90 %.
9) Not true about varicella infection-
A. Secondary attack rate is 90%
B. Lesions occur on flexor surfaces
C. Only single stage of lesion is present at a time
D. Reactivation occur in 10-30% cases
Ans.: -(c) Only single stage of lesion is present at a time [Ref: 23rd /e p. 144]
Exp.:- The characteristic feature of chicken pox is “Pleomorphism”, that is, all stages of the rash (papules, vesicles and crusts) may be seen simultaneously at time in the same area.
:-Chicken pox (varicella infection) is highly communicable by droplet infection with a secondary attack rate of approximately 90%.
:-Rashes of chicken pox are symmetrical and occur mostly on flexor surface.
:-Latent infection is established in cranial nerve, sensory ganglia and spinal dorsal root ganglia. The virus may reactivate in immunosuppressive conditions, resulting in herpes zoster in about 10-30% of persons.
10) Chicken pox vaccine is-
A. Live vaccine
B. Killed vaccine
C. Conjugated vaccine
D. None
Ans.: - (a) Live vaccine [Ref: 23rd /e p. 145]
Exp.:- Varicella vaccine is live attenuated vaccine and is recommended for children between 12-18 months of age.
11) Incubation period of measles-
A. 14 days
B. 1 Month
C. 3 Month
D. 5 Month
Ans.: - (a) 14 days [Ref: 23rd /e p. 145]
Exp.:- Incubation period of measles is 10-14 days.
12) Which of the following statements is true about the epidemiological determinants of measles-
A. Measles virus survives outside the human body for 5 days
B. Carriers are important sources of infection
C. Secondary attack is less than that of rubella
D. Incidence of measles is more in males than females
Ans.:- (c) Secondary attack is less than that of rubella [Ref: 23rd /e p. 147]
Exp.:- SAR of some important infectious diseases
Measles —80%
Rubella —90-95%
Chicken pox — ~90%
Pertussis -- ~90%
Mumps -- ~86%
About other options
The measles virus cannot survive outside the human body for any length of time. But it retains infectivity when stored at sub – zero temperature.
The only source of infection is a case of measles, carriers are not known to occur.
Incidence of measles is same in males and females.
13) Measles is infectious during-
A. After 4 days of rash
B. 4 days before and 5 days after rash
C. Throughout disease
D. Only in incubation period
Ans.:- (b) 4 days before and 5 days after rash [Ref: 23rd /e p. 147]
Exp.:- the period of communicability for measles is 4 days before and 5 days after the appearance of rash.
14) Which of the following is the “Least common” complication of measles-
A. Diarrhea
B. Pneumonia
C. Otitis media
D. SSPE
Ans.:- (d) SSPE [Ref: 23rd /e p. 148]
Exp.:- Sub-acute sclerosing panencephalitis (SSPE) is a rare complication of measles, which develops many years after the initial infection.
:- The most common complications are : measles – associated diarrhea, pneumonia and otitis media-
15) Most serious complication of measles is-
A. Koplik spots
B. Parotitis
C. Meningoencephalitis
D. Nephritis
Ans.:- (c) Meningoencephalitis[Ref: 23rd /e p. 148]
Exp.:- Neurological complications are more severe, e.g., febrile convulsions, encephalitis, and SSPE.
16) Reconstituted measles vaccine should be used with in-
A. 1 hour
B. 3 hour
C. 6 hour
D. 12 hour
Ans.:- (a) 1 hour [Ref: 23rd /e p. 148]
Exp.:- “The reconstituted vaccine should be kept on ice and used within one hour”.
17) India started 2-dose vaccination strategy for measles, in-
A. 2008
B. 2009
C. 2010
D. 2011
Ans. :- (c) 2010 [Ref: Park 20th /e 138]
Exp.:- In the 2010, the world’s two most populous countries made promising advancing measles control:-
China held the largest ever SIA, vaccinating more than 103 million children.
India started implementation of 2- dose vaccination strategy.
18) All the true about measles except –
A. Incubation period is 10-14 days
B. Secondary attack rate is 30-40%
C. Sub cutaneous vaccine is available
D. Vaccine is live attenuated
Ans.:- (b) Secondary attack rate is 30-40% [Ref: Park 23th /e 147]
Exp.:- SAR of measles is approximately 80%.
19) Definition of measles elimination-
A. <1/1000
B. <1/10000
C. <1/100000
D. <1/100
Ans.:- (c) 1<100000 [Ref: Park 23th /e 150]
Exp.:-
WHO defines elimination of measles as the absence of endemic measles for a period of >_ 12 months in the presence of adequate surveillance.
One indicator of measles elimination is a sustained measles incidence < 1/100, 000 population.
In 2005, the World Health Assembly set a goal of achieving a 90% reduction in global measles mortality by 2010 as compared with level in 2000.
20) Measles vaccination compaign between 9-14 years age for elimination is-
A. Keep up
B. Follow up
C. Mop up
D. Catch up
Ans.:- (d) Catch up [Ref: Park 23rd /e p. 149 & 22th /e p. 135-138]
Exp.:-
WHO’s measles elimination strategy comprises a three part vaccination strategy, i.e:-
Catch up one time, nationwide vaccination campaign targeting usually all children aged 9 months to 14 years regardless of history of measles disease or vaccination status.
Keep up routine service aimed at vaccinating more than 95% of each successive birth cohort
Follow-up subsequent nationwide vaccination campaign conducted every 2-4 years targeting usually all children born after catch up campaign.
21) Sub-acute sclerosing pan-encephalitis is associated with-
A. Mumps
B. Measles
C. Rubella
D. Typhoid
E. Diphtheria
Ans. :- (b) Measles [Ref: Park 23rd /e p. 148 & 22th /e p. 139]
22) All of following are true about measles except-
A. Maximum incidence in 6m-3 years age group
B. Best age for immunization is 9-12 months
C. Secondary attacks rate is 30%
D. I.P.= 7-14 days
Ans.:- (c) Secondary attacks rate is 30% [Ref: Park 23rd /e p. 147& 22th /e p. 138 & 139]
23) Measles vaccination is given at-
A. 9 months
B. At birth
C. 4 weeks
D. 8 weeks
E. Secondary attacks rate is 30%
Ans.:- (a) 9 months [Ref: Park 23rd /e p. 149 & 22th /e p. 140]
Exp.:-
The WHO expanded program on immunization recommends immunization at 9 months of age.
Now, second dose of measles is also given at 16-24 months in national immunization schedule.
24) In measles vaccine can be given within-
A. 3 months
B. 5 months
C. 7 months
D. 6 months
Ans.:- (d) 6 months [Ref: Park 23rd /e p. 149 & 22th /e p. 140]
Exp.:-
The best age for measles vaccination is 9 months.
It can be lowered to 6 months if there is measles outbreak in the community. For infants immunized between 6 months and 9 months of age, second dose should be administrated as soon as possible after child reaches the age of 9 months provided that at least for weeks have elapsed since the last dose.
25. To eradicate measles the percentage of population to be vaccinated is at least_________%-
A. 70
B. 80
C. 85
D. 95
Ans.:- (d) 95[Ref: Park 23rd /e p. 149]
Exp.:-
Epidemic of measles occur if proportion of susceptible children is >40%.
If measles is introduced in virgin community it infects >90% of children.
Eradication of measles require vaccine coverage >96%.
26. Measles epidemic can be anticipated when proportion of susceptible children in a community reaches-
A. 20%
B. 40%
C. 60%
D. 80%
Ans. :- (b) 40%
Exp.:-
Measles is endemic all over the world.
So if the proportion of susceptible in terms of unvaccinated children, new births or immigrants reaches 40% the protection afforded by herd immunity
27. Incubation period of rubella is-
A. 18-72 hours
B. 2-3 weeks
C. 1-3 months
D. >1 years
Ans.:- (b) 2-3 weeks [Ref: Park 23rd /e p. 150& 22th /e p. 142]
Exp.:-
Incubation period of rubella is 2-3 weeks.
28. Rubella virus was isolated in-
A. 1862
B. 1912
C. 1932
D. 1962
Ans. :- (d) 1962[Ref: Park 23rd /e p. 150& 22th /e p. 141]
Exp.:-
Rubella virus was isolated in 1962 and live attenuated vaccine was developed in 1967.
29. Under eradication of congenital rubella syndrome program the first priority group for rubella vaccination is-
A. All non-pregnant women of age 15 to 34
B. All adolescent non pregnant girls 15 to 24 years of age
C. All female children at one year
D. All non-pregnant women
Ans.:- (a) All non-pregnant women of age 15 to 34[Ref: Park 23rd /e p.151 & 22nd /e p. 142-143]
30. Rubella vaccine is given in which age –
A. 1-14 years
B. <5 years
C. >50 years
D. None
Ans.:- (a) 1-14 years [Ref: Park 23rd /e0 p. 151]
31. Risk of the damage of fetus by maternal rubella is maximum if mother gets infected in-
A. 6-12 weeks of pregnancy
B. 20-24 weeks of pregnancy
C. 21-25 weeks of pregnancy
D. 32-36 weeks of pregnancy
Ans.:- (a) 6-12 weeks of pregnancy [Ref: Park 23rd /e p.151 & 22nd /e p. 142]
32. Most common viral disease affecting parotid glands-
A. Mumps
B. Measles
C. Rubella
D. Varicella
Ans. :- (a) Mumps [Ref: Park 23rd /e p. 152 & 22nd /e p. 143]
Exp.:-
Among the given the options mumps affect salivary glands most commonly.
33. Commonest complication of mumps is –
A. Orchitis and oophritis
B. Encephalitis
C. Pneumonia
D. Myocarditis
Ans.:- (a) Orchitis and oophritis[Ref: Harrison 18th /e p. 1609 & 17th /e p. 1220]
Exp.:-
Orchitis is most common manifestation of mumps among sub-pubertal males.
34. With reference to mumps which of the following is true-
A. Meningoencephalitis can precede parotitis
B. Salivary gland involvement is limited to the parotid
C. The patient is not infectious prior to clinical parotid enlargement
D. Mumps orc Meningoencephalitis can precede parotitis
Ans.:-(a) Meningoencephalitis can precede parotitis[Ref: Harrison 18th /e p. 1608& 1609 & 17th /e p. 1220]
Exp.:-“Aseptic meningitis may develope before, during, after or in the absence of parotitis.”
Mainly parotid glands are involve, but sublingual and sub-maxillary glands may also be involved.
Patient is infectious 4-6 days before onset of swelling.
Sterility after mumps orchitis is rare.
35. Incubation period of Mumps-
A. 4-5 days
B. 7-15 days
C. 12-24 days
D. 50 days
Ans.:- (c) 12-24 days [Ref: Park 23rd /e p. 152 & 21st / e p. 137]
36. Incubation period of influenza –
A. 18 – 72 hours
B. 1 – 6 hours
C. 5 – 10 hours
D. <1 hours
Ans.:- (a) 18-72 hours [Ref: Park 23rd /e p. 154 & 22nd / e p. 146]
Exp.:-
Incubation period of influenza is 18-72 hours
37. Influenza pandemic is mainly caused by-
A. Type A
B. Type B
C. Type C
D. All
Ans.:- (a) Type A [Ref: Park 23rd /e p. 154 &22nd /e p. 145]
Exp.:-
Type A causes all pandemics and most of the epidemics.
38. Antigenic variation seen in which of the following –
A. Influenza virus
B. Hepatitis virus
C. Yellow fever virus
D. Leptospira
Ans.:- (a) influenza virus [Ref: Park 23rd /e p.145 & 22nd /e p. 144]
Exp.:-
Unique feature of influenza virus is its ability to undergo antigenic variation.
Antigenic variability is highest in influenza virus Type A, less in Type B, while it is not been demonstrated in Type C.
39. True regarding antigenic shift –
A. Gradual
B. Seen in influenza A & B
C. Due to genetic recombination
D. Due to point mutation
Ans.:- (c) Due to genetic recombination [Ref: Park 23rd /e p. 154 & 20th /e p. 145]
Exp.:-
Antigenic drift
Antigenic change is gradual over a period of time.
New antigens though different from the previous antigens, are yet related to them.
Antigenic drift involves point mutation in the gene owing to selection pressure by immunity in the population.
Antigenic drift accounts for the periodic epidemics of influenza.
Occurs every 2-3 years in case of influenza A and every 4-7 years in case of influenza B.
Antigenic shift
And abrupt, drastic discontinuous variation in the antigenic structure.
Result from genetic recombination of human with animal or avian virus.
Accounts for major epidemics or pandemics.
Occurs every 10-15 years.
Occurs in influenza A only
40. False about antigen drift-
A. Causes pandemic
B. Occurs due to mutation
C. Occurs more frequently
D. Affected by previous antibodies
Ans.:- (a) Causes pandemic [Ref: 23rd /e p. 154 & Ananthanarayan 8th /e p.496]
Exp.:-
Antigenic shift is responsible for pandemic.
Antigenic drift occurs due to point mutation.
Antigenic drift occurs more frequently (2-3 years) then antigenic shift (10-15 years).
Antigenic drift is influenced by presence of antibody to the predecessor strains in the host population.
41. Not true regarding influenza virus is-
A. All types exhibit antigenic shift
B. Only type A shows antigenic drift
C. Drift is accumulation of point mutations
D. None of the above
Ans.:-(a) All types exhibit antigenic shift & (b) Only type A shows antigenic drift[Ref: Park 23rd /e p.154 & 22nd /e p. 145]
Exp.:-
Antigenic shift is seen only in influenza A virus.
Antigenic drift is seen only in influenza A & b virus.
Antigenic drift involves point mutation in the gene owing to selection pressure by immunity in the host population.
42. True about epidemiology of influenza –
A. Asymptomatic seen rarely
B. Incubation period 10-12 hours
C. Pandemic rare
D. Extra human reservoir not seen
E. All ages sex are equally affected
Ans.:- (e) all ages sex are equally affected [Ref: Park 23rd /e p.154 & 22nd /e p.145
Influenza affects all ages and both sexes
About other options
Most infections are subclinical.
Incubation period is 18-72 hrs.
Influenza causes pandemic every 10-15 years.
Major reservoir of influenza virus exist in animals and birds.
43. H5N1 is a strain of –
A. Avian flu
B. New vaccine against AIDS
C. Agent for Japanese encephalitis
D. Causes Chickengunya fevers
Ans.:- (a) Avian flu [Ref: Park 23rd /e p. 153& Harrison 18th /e p. 1494 & 17th /e p. 1127]
Exp.:-
In 1997, human cases of influenza caused by avian influenza viruses (A/H5N1) were detected in Hong-Kong during an extensive outbreak of influenza in poultry.
All these cases were associated with contact with infected poultry.
44. Which of the following lead to an outbreak of Influenza in China in 2013 –
A. H1N1
B. H3N2
C. H2N2
D. H7N9
E. H5N1
Ans.:- (d) H7N9 [Ref: WHO H7N9 Avian influenza 2013 document]
Exp.:-
In china, there was an outbreak of influenza caused by avian influenza H7N9 in 2013
It started in china and spread to Hong-Kong.
All these cases were associated with contact with infected poultry.
45. Pig in H1N1 influenza acts as?
A. Carrier
B. Amplifying host
C. Reservoir
D. Vector
Ans.:- (c) Reservoir [Ref: Park 23rd /e p. 154& www.fass.org]
Exp.:-
“Pig serve as major reservoir of H1N1 & H3N2 influenza viruses which are endemic in pig population worldwide and are responsible for one of the most prevalent respiratory diseases in pigs.”………..www.fass.org
46. Swine flu is caused most commonly by –
A. H1N1
B. H5N1
C. H3N2
D. B virus
Ans.:- (a) H1N1 [Ref: Essentials of microbiology 701]
Exp.:-
Swine flu is most commonly caused by H1N1 influenza 4
Other influenza virus causing swine flu occasionally are H1N2, H2N1, H3N2 & H
47. Incubation period of swine flu –
A. 1-3 days
B. 2-3 weeks
C. 10-15 days
D. 5 weeks
Ans.:- (a) 1-3 days [Ref: Essentials of Microbiology p. 701]
Exp.:-
Swine flu, also called swine influenza, pig influenza, is caused by influenza virus.
Incubation period is about 1-3 days and the symptoms of swine flu in humans are similar to most influenza infection, e.g., fever, cough, rhinorrhea, fatigue and headache.
48. Most common source of Diphtheria-
A. Case
B. Carrier
C. Both
D. None
Ans.:- (b) Carrier [Ref: Park 23rd /e p. 160]
Exp.:- Source of infection cases of carriers; carriers are common sources of infection, there ratio is estimated to be 95 carriers for clinical cases.
49. The infectivity of a patient with diphtheria is-
A. Till cough subsides
B. Till patient is febrile
C. Life long
D. For 15 days after infection
Ans.:- (d) For 15 days after infection [Ref: Park 23rd /e p. 161]
Exp.:-
The period of infectivity may vary from 14 to 28 days from the onset of the disease, but carriers may remain infective for much longer period.
A case or carrier may be considered non – communicable when at least to cultures properly obtain from nose and throat, 24 hours apart, are negative for diphtheria bacilli.
50. A herd immunity of over - % is considered necessary to prevent epidemic spread of diphtheria-
A. 50%
B. 55%
C. 60%
D. 70%
Ans.:- (d) 70% infection [Ref: Park 23rd /e p. 161]
Exp.:- A herd immunity of over 70% is considered necessary to prevent epidemic spread, but some believe that the critical level may be as high as 90%.
