A 34-year-old farm worker in Chhattisgarh, detected in a house-to-house leprosy case detection campaign, has 7 hypopigmented, hypoaesthetic patches on the trunk and limbs and a thickened, tender right ulnar nerve. A slit-skin smear shows no acid-fast bacilli. Under the National Leprosy Eradication Programme, what treatment does he need?

Multibacillary MDT for 12 months

Multibacillary MDT for 24 months

Single-dose rifampicin, then review

Paucibacillary MDT for 6 months

A 30-year-old woman with sputum-positive, rifampicin-sensitive pulmonary TB has just started treatment. At contact screening, her 3-year-old son is active and gaining weight, with no cough, fever or lymph nodes; active TB is ruled out. He received BCG at birth. What should be offered to him under NTEP?

TB preventive treatment, now that active TB is excluded

The full four-drug regimen for six months, as for active TB

No drug; review only if symptoms appear

Repeat BCG vaccination, then observe him

A 45-year-old farmer comes to the PHC because the stray dog that bit his calf 3 weeks ago has now died. The bite drew blood, and he only washed it with water at the time. He has no symptoms. He asks whether it is too late for treatment. What is the most appropriate step?

Full prophylaxis now with immunoglobulin and vaccine

Vaccine only, since immunoglobulin is too late

No prophylaxis, as the incubation period has passed

Wait for symptoms, then start vaccine and immunoglobulin

A PHC serving 40,000 people reports only 4 malaria cases in the past year and wants to be declared low risk. The district malaria officer notes that only 1,600 blood smears were examined in that year. How should the low case count be interpreted?

Surveillance is inadequate, so cases may be missed

The slide positivity rate proves low transmission

The area has reached the elimination category

Malaria has been eliminated from this area

Communicable disease epidemiology and control

30 NEET-PG practice questions on Communicable disease epidemiology and control, part of Community Medicine. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Hard
A 34-year-old farm worker in Chhattisgarh, detected in a house-to-house leprosy case detection campaign, has 7 hypopigmented, hypoaesthetic patches on the trunk and limbs and a thickened, tender right ulnar nerve. A slit-skin smear shows no acid-fast bacilli. Under the National Leprosy Eradication Programme, what treatment does he need?
1. AMultibacillary MDT for 24 months
2. BSingle-dose rifampicin, then review
3. CMultibacillary MDT for 12 months
4. DPaucibacillary MDT for 6 months
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Answer: C · Multibacillary MDT for 12 months
NLEP classes leprosy as multibacillary when there are 6 or more skin lesions, any nerve trunk involvement, or a positive skin smear; any one is enough. He has 7 patches and a thickened nerve, so he is multibacillary even though his smear is negative, and a negative smear never makes a case paucibacillary. The adult MB regimen is rifampicin 600 mg and clofazimine 300 mg once a month under supervision, with dapsone 100 mg and clofazimine 50 mg daily, for 12 months. Single-dose rifampicin is the post-exposure prophylaxis offered to his household and close contacts, not treatment for him.
- A: The 24-month MB course was shortened to 12 months long ago.
- B: Single-dose rifampicin is prophylaxis for contacts, not treatment.
- D: Treating him as paucibacillary because the smear is negative undertreats MB disease.
Question 2 · Medium
A 30-year-old woman with sputum-positive, rifampicin-sensitive pulmonary TB has just started treatment. At contact screening, her 3-year-old son is active and gaining weight, with no cough, fever or lymph nodes; active TB is ruled out. He received BCG at birth. What should be offered to him under NTEP?
1. AThe full four-drug regimen for six months, as for active TB
2. BTB preventive treatment, now that active TB is excluded
3. CNo drug; review only if symptoms appear
4. DRepeat BCG vaccination, then observe him
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Answer: B · TB preventive treatment, now that active TB is excluded
Young household contacts of pulmonary TB are at high risk of infection and of rapid progression to severe disease. Under NTEP, a child under 5 years in contact with a pulmonary TB patient receives TB preventive treatment once active disease has been excluded, without needing a test for infection; isoniazid daily for 6 months is the regimen widely used at this age. BCG given at birth does not remove the need for preventive treatment. Excluding active TB first is essential, because treating active disease with a single drug breeds resistance.
- A: Full treatment is for active disease, which has been ruled out.
- C: Waiting for symptoms risks progression to severe childhood TB.
- D: BCG is not repeated and does not protect an exposed child.
Question 3 · Medium
A 45-year-old farmer comes to the PHC because the stray dog that bit his calf 3 weeks ago has now died. The bite drew blood, and he only washed it with water at the time. He has no symptoms. He asks whether it is too late for treatment. What is the most appropriate step?
1. AVaccine only, since immunoglobulin is too late
2. BNo prophylaxis, as the incubation period has passed
3. CFull prophylaxis now with immunoglobulin and vaccine
4. DWait for symptoms, then start vaccine and immunoglobulin
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Answer: C · Full prophylaxis now with immunoglobulin and vaccine
A bleeding bite is a category III exposure, and post-exposure prophylaxis is started whenever the person presents, however late, as long as there are no symptoms of rabies. The incubation period is usually 1-3 months but may be much longer, so three weeks is well within the period of risk. Because he has never received vaccine, immunoglobulin is still given with the first dose, along with wound care. Once symptoms appear, rabies is almost always fatal, so prophylaxis after that point is useless.
- A: Immunoglobulin is withheld only when vaccine was started more than 7 days ago.
- B: The incubation period often lasts months; three weeks is not too late.
- D: Prophylaxis cannot work once clinical rabies begins.
Question 4 · Medium
A 40-year-old man newly diagnosed with multibacillary leprosy is examined for disability at the PHC. Both palms have lost sensation but show no visible damage or deformity, his feet are normal, and he cannot close his right eye completely (lagophthalmos). Visual acuity is normal. What is his WHO disability grade?
1. AGrade 1
2. BGrade 2
3. CGrade 3
4. DGrade 0
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Answer: B · Grade 2
The WHO disability grading records grade 0, 1 or 2 for each eye, hand and foot, and the highest grade of any site is the patient's overall grade. Loss of sensation in the palms without visible damage is grade 1 for the hands. Lagophthalmos is visible damage to the eye, which is grade 2, so his overall grade is 2. The proportion of new cases with grade 2 disability reflects late detection, and every such patient needs care to prevent further damage.
- A: Grade 1 applies to his hands, but the eye has visible damage.
- C: There is no grade 3 in the WHO leprosy disability grading.
- D: Grade 0 would need no sensory loss and no visible damage.
Question 5 · Medium
A PHC serving 40,000 people reports only 4 malaria cases in the past year and wants to be declared low risk. The district malaria officer notes that only 1,600 blood smears were examined in that year. How should the low case count be interpreted?
1. AThe slide positivity rate proves low transmission
2. BThe area has reached the elimination category
3. CMalaria has been eliminated from this area
4. DSurveillance is inadequate, so cases may be missed
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Answer: D · Surveillance is inadequate, so cases may be missed
The annual blood examination rate is 1,600 / 40,000 x 100 = 4%, well below the 10% generally regarded as the minimum for adequate surveillance. With so few smears examined, a low annual parasite incidence may reflect missed cases rather than low transmission. The first step is to strengthen active and passive fever surveillance, including testing every fever case with a rapid test or smear. Indicators such as API are reliable only when the ABER is adequate.
- A: Positivity among few slides cannot prove low transmission.
- B: Categorisation by API assumes adequate case detection, missing here.
- C: Elimination needs adequate surveillance showing no local transmission.
Question 6 · Hard
A 45-kg woman has multiple bleeding dog bites on both forearms (category III exposure). The district hospital has equine rabies immunoglobulin (ERIG) at a strength of 200 IU/mL; human rabies immunoglobulin is not available. What volume of ERIG should be prepared for wound infiltration?
1. A4.5 mL
2. B18 mL
3. C9 mL
4. D1.8 mL
Answer and explanation in LearnFree account
Question 7 · Medium
A 26-year-old woman was licked on the lips by a stray dog that jumped at her in the market; the dog ran away. She has no bite or scratch anywhere. At the urban PHC the medical officer reviews the contact. How should this exposure be categorised and treated?
1. ACategory I: wash only, no prophylaxis
2. BCategory II: immunoglobulin without vaccine
3. CCategory II: vaccine without immunoglobulin
4. DCategory III: vaccine and immunoglobulin
Answer and explanation in LearnFree account
Question 8 · Hard
A PHC serves a population of 60,000. In the past year, 7,200 blood smears were examined and 180 were positive for malaria parasites, of which 108 were Plasmodium falciparum. What is the annual parasite incidence (API) of this area?
1. A3.0 per 1,000 population
2. B2.5 per 1,000 population
3. C30 per 1,000 population
4. D1.8 per 1,000 population
Answer and explanation in LearnFree account
Question 9 · Medium
A 30-year-old veterinary assistant was bitten on the hand by a stray dog today and the wound bled. Two years ago, after a similar bite, he completed a full course of post-exposure prophylaxis with vaccine and immunoglobulin, which is recorded on his card. Besides wound washing, what prophylaxis does he need now?
1. AA full five-dose vaccine course along with immunoglobulin again
2. BNo vaccine, as protection lasts for life
3. CImmunoglobulin alone, as he already has memory
4. DTwo vaccine doses, on days 0 and 3, without immunoglobulin
Answer and explanation in LearnFree account
Question 10 · Medium
In a dengue-endemic town, the municipal health officer asks every household to empty, scrub and dry all water containers, coolers and flower vases once every week (a 'dry day'). Why is a weekly interval chosen?
1. AThe virus survives in stored water for only a week
2. BAedes takes about a week to develop from egg to adult
3. CAdult Aedes mosquitoes live for only about a week
4. DAedes eggs die if kept dry for longer than a week
Answer and explanation in LearnFree account
Question 11 · Medium
A 9-year-old girl is brought to the PHC 30 minutes after a stray dog bit her calf, causing a bleeding wound. The medical officer considers these steps: 1. Wash the wound with soap and running water for about 15 minutes. 2. Apply povidone-iodine or another virucidal antiseptic after washing. 3. Suture the wound at once to reduce contamination. 4. Infiltrate rabies immunoglobulin into and around the wound. Which steps are correct?
1. A2, 3 and 4 only
2. B1, 3 and 4 only
3. C1 and 4 only
4. D1, 2 and 4 only
Answer and explanation in LearnFree account
Question 12 · Easy
A 32-year-old woman comes to the PHC anxious because a stray puppy licked the back of her hand while she was feeding it this morning. On examination the skin is intact, with no scratch or abrasion. The puppy cannot be traced. What does she need?
1. AWashing of the area only; no vaccine
2. BAnti-rabies vaccine and immunoglobulin
3. CVaccine only if the puppy dies in 10 days
4. DWound washing and anti-rabies vaccine
Answer and explanation in LearnFree account
Question 13 · Medium
A district leprosy officer reviews last year's data: of 220 new leprosy cases detected, 26 (about 12%) were children under 15 years, and the proportion has risen over three years. What does this rising proportion of child cases most strongly indicate?
1. ABetter detection of old cases in adults
2. BOngoing recent transmission in the community
3. CRelapse of cases treated in earlier years
4. DRising resistance to multidrug therapy
Answer and explanation in LearnFree account
Question 14 · Medium
During a dengue outbreak in a town, a mother asks the school health doctor how to protect her 8-year-old son, who already sleeps under a bed net at night. Which advice best targets the behaviour of the vector?
1. ASleeping under an insecticide-treated net at night
2. BClosing windows from dusk until dawn
3. CRepellent and full-sleeved clothes during the day
4. DBurning mosquito coils after sunset
Answer and explanation in LearnFree account
Question 15 · Easy
During a measles outbreak in a tribal block, the medical officer explains to schoolteachers when an infected child spreads the disease most. When is a child with measles most infectious?
1. AIn the prodromal stage, before the rash
2. BWhen the rash is at its peak
3. CDuring the stage of fading rash
4. DDuring convalescence after the rash
Answer and explanation in LearnFree account
Question 16 · Medium
A village in a malaria-endemic district has several permanent ponds and unused wells that breed Anopheles throughout the year. The block health team wants a long-lasting, low-cost biological control measure for these water bodies. What should be used?
1. ASpace fogging with malathion each week
2. BIndoor residual spraying of house walls
3. CLarvivorous fish such as Gambusia or guppy
4. DParis green dust applied to drinking wells
Answer and explanation in LearnFree account
Question 17 · Hard
During a dengue outbreak, a larval survey in a town ward inspects 250 houses. Aedes larvae or pupae are found in 40 houses. Of 800 water-holding containers inspected, 60 are positive. What is the Breteau index?
1. A24
2. B0.24
3. C7.5
4. D16
Answer and explanation in LearnFree account
Question 18 · Medium
A cluster of malaria cases is reported among workers at a large construction site in a metropolitan city. The entomology team finds Anopheles larvae in overhead water tanks, curing tanks and wells on the site. Which vector is most likely responsible?
1. AAnopheles culicifacies
2. BAnopheles sundaicus
3. CAnopheles fluviatilis
4. DAnopheles stephensi
Answer and explanation in LearnFree account
Question 19 · Medium
A 6-year-old boy in a village is diagnosed with measles. His 3-year-old sister, who has never been vaccinated and is otherwise healthy, has been sleeping in the same room; her first contact with him while he was infectious was about 36 hours ago. What is the best step for her?
1. AGive measles-rubella vaccine now
2. BWait two weeks, then vaccinate if no rash
3. CGive oral vitamin A and observe her
4. DSeparate her from her brother; nothing else
Answer and explanation in LearnFree account
Question 20 · Hard
The district immunisation officer is planning a catch-up campaign to interrupt measles transmission. She assumes a basic reproduction number (R0) of 15 for measles and an effectiveness of 95% for two doses of vaccine. Approximately what vaccine coverage is needed to reach the herd immunity threshold?
1. AAbout 89%
2. BAbout 93%
3. CAbout 95%
4. DAbout 98%
Answer and explanation in LearnFree account
Question 21 · Easy
During a dengue outbreak, an ANM finds Aedes larvae in large earthen pots of drinking water that a family cannot empty. Which larvicide is used at a concentration of 1 ppm in such potable water containers?
1. AMalathion
2. BTemephos
3. CFenthion
4. DParis green
Answer and explanation in LearnFree account
Question 22 · Hard
A 7-year-old unvaccinated boy develops measles. His household has 8 other members: four adults, all of whom had measles in childhood, and four children, one of whom has a documented two doses of measles-rubella vaccine while three are unvaccinated. Within the next 7-14 days, 2 of the unvaccinated children develop measles. What is the secondary attack rate in this household?
1. A50%
2. BAbout 67%
3. C25%
4. DAbout 33%
Answer and explanation in LearnFree account
Question 23 · Medium
A 12-year-old boy is brought to a sub-centre after a pet cat scratched his forearm while he was playing with it an hour ago. There are two superficial scratches with no bleeding. The cat's vaccination status is unknown. What post-exposure prophylaxis does he need after washing the wound?
1. AImmunoglobulin alone, infiltrated into the wound
2. BAnti-rabies vaccine without immunoglobulin
3. CAnti-rabies vaccine with immunoglobulin
4. DNo prophylaxis, as cats rarely transmit rabies
Answer and explanation in LearnFree account
Question 24 · Easy
A state TB cell wants a single indicator that reflects how much Mycobacterium tuberculosis is currently being transmitted in the community, and plans tuberculin or IGRA surveys of children for it. Which indicator is this?
1. AAnnual risk of tuberculous infection
2. BPrevalence of sputum-positive cases
3. CCase notification rate of all TB
4. DMortality rate from tuberculosis
Answer and explanation in LearnFree account
Question 25 · Easy
During a malaria entomological survey at a village pond, a health worker collects mosquito larvae that lie parallel to the water surface and have no respiratory siphon. Which genus do these larvae belong to?
1. AAnopheles
2. BAedes
3. CMansonia
4. DCulex
Answer and explanation in LearnFree account

5 more Communicable disease epidemiology and control questions

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Communicable disease epidemiology and control

A 45-year-old farmer comes to the PHC because the stray dog that bit his calf 3 weeks ago has now died. The bite drew blood, and he only washed it with water at the time. He has no symptoms. He asks whether it is too late for treatment. What is the most appropriate step?

A PHC serving 40,000 people reports only 4 malaria cases in the past year and wants to be declared low risk. The district malaria officer notes that only 1,600 blood smears were examined in that year. How should the low case count be interpreted?

A 45-kg woman has multiple bleeding dog bites on both forearms (category III exposure). The district hospital has equine rabies immunoglobulin (ERIG) at a strength of 200 IU/mL; human rabies immunoglobulin is not available. What volume of ERIG should be prepared for wound infiltration?

A 26-year-old woman was licked on the lips by a stray dog that jumped at her in the market; the dog ran away. She has no bite or scratch anywhere. At the urban PHC the medical officer reviews the contact. How should this exposure be categorised and treated?

A PHC serves a population of 60,000. In the past year, 7,200 blood smears were examined and 180 were positive for malaria parasites, of which 108 were Plasmodium falciparum. What is the annual parasite incidence (API) of this area?

In a dengue-endemic town, the municipal health officer asks every household to empty, scrub and dry all water containers, coolers and flower vases once every week (a 'dry day'). Why is a weekly interval chosen?

A 32-year-old woman comes to the PHC anxious because a stray puppy licked the back of her hand while she was feeding it this morning. On examination the skin is intact, with no scratch or abrasion. The puppy cannot be traced. What does she need?

A district leprosy officer reviews last year's data: of 220 new leprosy cases detected, 26 (about 12%) were children under 15 years, and the proportion has risen over three years. What does this rising proportion of child cases most strongly indicate?

During a dengue outbreak in a town, a mother asks the school health doctor how to protect her 8-year-old son, who already sleeps under a bed net at night. Which advice best targets the behaviour of the vector?

During a measles outbreak in a tribal block, the medical officer explains to schoolteachers when an infected child spreads the disease most. When is a child with measles most infectious?

A village in a malaria-endemic district has several permanent ponds and unused wells that breed Anopheles throughout the year. The block health team wants a long-lasting, low-cost biological control measure for these water bodies. What should be used?

During a dengue outbreak, a larval survey in a town ward inspects 250 houses. Aedes larvae or pupae are found in 40 houses. Of 800 water-holding containers inspected, 60 are positive. What is the Breteau index?

A cluster of malaria cases is reported among workers at a large construction site in a metropolitan city. The entomology team finds Anopheles larvae in overhead water tanks, curing tanks and wells on the site. Which vector is most likely responsible?

A 6-year-old boy in a village is diagnosed with measles. His 3-year-old sister, who has never been vaccinated and is otherwise healthy, has been sleeping in the same room; her first contact with him while he was infectious was about 36 hours ago. What is the best step for her?

During a dengue outbreak, an ANM finds Aedes larvae in large earthen pots of drinking water that a family cannot empty. Which larvicide is used at a concentration of 1 ppm in such potable water containers?

A 12-year-old boy is brought to a sub-centre after a pet cat scratched his forearm while he was playing with it an hour ago. There are two superficial scratches with no bleeding. The cat's vaccination status is unknown. What post-exposure prophylaxis does he need after washing the wound?

A state TB cell wants a single indicator that reflects how much Mycobacterium tuberculosis is currently being transmitted in the community, and plans tuberculin or IGRA surveys of children for it. Which indicator is this?

During a malaria entomological survey at a village pond, a health worker collects mosquito larvae that lie parallel to the water surface and have no respiratory siphon. Which genus do these larvae belong to?