A 9-month-old infant is brought to the ICTC for follow-up. The mother is HIV-positive on ART and is still breastfeeding. A rapid HIV antibody test on the infant is reactive. What is the next step to establish whether the infant is infected?

Repeat with two more rapid kits

A 50-year-old man with chronic hepatitis C asks why there is still no vaccine for hepatitis C when there is one for hepatitis B. Which property of HCV is the main reason?

Hypervariable envelope regions forming quasispecies

A DNA genome that integrates into hepatocytes

Spread only through the faeco-oral route

Absence of any envelope on the virion

A 26-year-old woman had a single high-risk exposure 16 days ago. A third-generation (antibody-only) HIV ELISA is non-reactive, but a fourth-generation test on the same sample is reactive, and later testing confirms infection. Why did the fourth-generation test turn positive earlier?

It also detects HIV p24 antigen

It detects proviral DNA in leucocytes

It uses a whole-virus lysate antigen

Hepatitis viruses and HIV

33 NEET-PG practice questions on Hepatitis viruses and HIV, part of Microbiology. 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 9-month-old infant is brought to the ICTC for follow-up. The mother is HIV-positive on ART and is still breastfeeding. A rapid HIV antibody test on the infant is reactive. What is the next step to establish whether the infant is infected?
1. ARepeat with two more rapid kits
2. BWestern blot
3. CCD4 cell count
4. DHIV-1 DNA PCR
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Answer: D · HIV-1 DNA PCR
Maternal IgG antibody crosses the placenta and can persist in the infant's blood for up to 18 months, so a reactive antibody test before 18 months does not prove infection. Infection must be confirmed by a virological test that detects the virus itself; in India's early infant diagnosis programme this is HIV-1 DNA PCR, usually on a dried blood spot. If it is positive, ART is started at once. Because breastfeeding continues the risk, a final antibody test is still needed after 18 months and at least six weeks after breastfeeding stops.
- A: More antibody kits only detect the same maternal antibody again.
- B: A Western blot also detects antibody and cannot separate maternal from infant antibody.
- C: CD4 counts guide management but do not diagnose infection, and infant values differ from adults.
Question 2 · Easy
During an outbreak of jaundice in a Hyderabad colony after sewage leaked into the drinking water pipeline, a 25-year-old woman at 32 weeks of pregnancy develops acute liver failure. Which virus is most likely responsible?
1. AHepatitis B virus
2. BHepatitis D virus
3. CHepatitis A virus
4. DHepatitis E virus
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Answer: D · Hepatitis E virus
Large water-borne outbreaks of hepatitis in adults in India are usually due to hepatitis E virus (genotype 1), spread by the faeco-oral route through contaminated water. HEV causes a self-limiting illness in most people but carries high mortality in pregnant women, especially in the third trimester, from acute liver failure. Diagnosis is by IgM anti-HEV. Safe drinking water and sanitation are the main preventive measures.
- A: HBV spreads by blood and sexual contact, not by sewage-contaminated water.
- B: HDV needs HBV, spreads by blood and is not the cause of water-borne outbreaks.
- C: HAV is also faeco-oral but mainly infects children and is not linked with high maternal mortality.
Question 3 · Easy
A 32-year-old man newly diagnosed with HIV asks how the virus enters his CD4 T cells. Which viral protein binds the CD4 molecule?
1. Agp120
2. Bp24
3. Cp17
4. Dgp41
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Answer: A · gp120
The envelope glycoprotein gp120 binds the CD4 molecule and then a chemokine co-receptor, CCR5 or CXCR4. This changes the shape of gp41, the transmembrane glycoprotein, which drives fusion of the viral and cell membranes. p24 is the capsid protein detected in fourth-generation tests, and p17 is the matrix protein. Maraviroc blocks CCR5 and enfuvirtide blocks gp41-mediated fusion.
- B: p24 is the capsid protein, not an attachment protein.
- C: p17 is the matrix protein lining the inside of the envelope.
- D: gp41 mediates membrane fusion after gp120 has bound CD4.
Question 4 · Medium
A 50-year-old man with chronic hepatitis C asks why there is still no vaccine for hepatitis C when there is one for hepatitis B. Which property of HCV is the main reason?
1. AA DNA genome that integrates into hepatocytes
2. BSpread only through the faeco-oral route
3. CHypervariable envelope regions forming quasispecies
4. DAbsence of any envelope on the virion
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Answer: C · Hypervariable envelope regions forming quasispecies
HCV is an RNA virus whose polymerase lacks proofreading, so it mutates rapidly. The hypervariable region of the E2 envelope glycoprotein changes constantly, producing a swarm of related variants (quasispecies) in each patient, and neutralising antibodies keep being escaped. This explains the high rate of chronic infection and the difficulty in making a vaccine. Direct-acting antivirals now cure most patients.
- A: HCV has an RNA genome and does not integrate.
- B: HCV spreads mainly through blood, not the faeco-oral route.
- D: HCV is an enveloped virus, with E1 and E2 glycoproteins.
Question 5 · Medium
A 26-year-old woman had a single high-risk exposure 16 days ago. A third-generation (antibody-only) HIV ELISA is non-reactive, but a fourth-generation test on the same sample is reactive, and later testing confirms infection. Why did the fourth-generation test turn positive earlier?
1. AIt also detects HIV p24 antigen
2. BIt detects only IgG antibody
3. CIt detects proviral DNA in leucocytes
4. DIt uses a whole-virus lysate antigen
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Answer: A · It also detects HIV p24 antigen
Fourth-generation assays detect both anti-HIV antibodies and the p24 capsid antigen. p24 antigen appears in blood during early viraemia, before antibodies are detectable, so these assays shorten the window period compared with antibody-only tests. Third-generation tests detect IgM and IgG antibodies, which take longer to appear. Nucleic acid tests shorten the window further.
- B: Detecting only IgG would make a test later, not earlier; third-generation tests already detect IgM.
- C: Proviral DNA PCR is a separate molecular test, not an ELISA.
- D: Whole-virus lysate was used in first-generation tests, which are less sensitive.
Question 6 · Medium
A 27-year-old primigravida at 16 weeks is HBsAg positive and HBeAg positive on antenatal screening. Her ALT is normal. Which test decides whether she should take tenofovir in the third trimester to protect her baby?
1. AHBV DNA viral load
2. BIgM anti-HBc
3. CLiver ultrasound
4. DAnti-HBe antibody
Answer and explanation in LearnFree account
Question 7 · Medium
A 36-year-old man from Goa is diagnosed with HIV-2 infection by a type-specific test. Consider these statements about HIV-2 compared with HIV-1: 1. It progresses to AIDS more slowly. 2. Plasma viral loads are usually lower. 3. It is naturally resistant to efavirenz and nevirapine. 4. It is the main type of HIV in India. Which statements are correct?
1. A1 and 4 only
2. B1 and 2 only
3. C1, 2 and 3 only
4. D1, 3 and 4 only
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Question 8 · Medium
A 10-year-old boy with thalassaemia major in a Gujarat hospital has had monthly transfusions for years, and every donor unit was negative for HBsAg on screening. He now has HBsAg and HBV DNA in his blood. What is the most likely way he acquired HBV?
1. AMosquito bites in the transfusion ward
2. BDonor with occult or window-period HBV
3. CReactivation of a vaccine-strain virus
4. DFaeco-oral spread from other children
Answer and explanation in LearnFree account
Question 9 · Hard
Four staff in a district hospital are screened before posting to the dialysis unit. P: HBsAg positive, HBeAg positive, IgG anti-HBc positive. Q: HBsAg negative, anti-HBc positive, anti-HBs positive. R: HBsAg negative, anti-HBc negative, anti-HBs positive. S: HBsAg negative, anti-HBc negative, anti-HBs negative. Which person is a chronic carrier with high infectivity?
1. AP
2. BR
3. CS
4. DQ
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Question 10 · Medium
A 22-year-old college student tested HIV antibody negative at an ICTC 12 days after unprotected sex with a casual partner. She is relieved and asks whether she can stop worrying. What should the counsellor advise?
1. AStart lifelong ART now as a precaution
2. BTest her partner instead of retesting herself
3. CNo further testing is needed after one negative test
4. DRetest after the window period and use condoms meanwhile
Answer and explanation in LearnFree account
Question 11 · Hard
A 27-year-old man is tested at an ICTC after a high-risk exposure 3 weeks earlier. The counsellor and the medical officer discuss his result. Consider these statements: 1. In the diagnostic strategy, the kits used must differ in antigen or principle. 2. A positive rapid test must be confirmed by Western blot before ART starts. 3. A positive result is disclosed in person with post-test counselling. 4. A negative antibody test today excludes infection from that exposure. Which statements are correct?
1. A1 and 2 only
2. B1 and 3 only
3. C2 and 4 only
4. D1, 3 and 4 only
Answer and explanation in LearnFree account
Question 12 · Medium
A 30-year-old pregnant woman is HBsAg positive. Her obstetrician also orders HBeAg, which is positive. What does a positive HBeAg chiefly indicate?
1. AIntegration of HBV DNA into hepatocytes
2. BRecovery with protective immunity
3. CCo-infection with hepatitis D virus
4. DActive replication and high infectivity
Answer and explanation in LearnFree account
Question 13 · Easy
A 28-year-old man donates blood at a regional blood centre. His HIV antibody ELISA is non-reactive, but he seroconverts 4 weeks later after a high-risk exposure that occurred a week before donation. What term describes the period in which he was infected but antibody-negative?
1. AIncubation period
2. BLatent period
3. CProdromal period
4. DWindow period
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Question 14 · Medium
A 29-year-old resident pricks her finger while suturing a patient who is HBsAg positive. She completed hepatitis B vaccination as an intern, and her anti-HBs then was 120 mIU/mL. What hepatitis B prophylaxis does she need?
1. AHepatitis B immunoglobulin alone
2. BHBIG and a vaccine booster
3. CA complete three-dose vaccine course
4. DNo hepatitis B prophylaxis
Answer and explanation in LearnFree account
Question 15 · Medium
A 42-year-old man on haemodialysis in Chennai is found to be anti-HCV positive on routine screening. HCV RNA by PCR, repeated twice a month apart, is not detected, and his ALT is normal. What is the best interpretation?
1. AAcute HCV in the window period
2. BPast HCV infection that has cleared
3. COccult HCV needing liver biopsy
4. DChronic hepatitis C needing treatment
Answer and explanation in LearnFree account
Question 16 · Easy
A 38-year-old woman with chronic hepatitis B is started on tenofovir. Tenofovir acts on HBV because the virus replicates its DNA genome through which enzyme?
1. AReverse transcriptase
2. BRNA-dependent RNA polymerase
3. CIntegrase
4. DViral protease
Answer and explanation in LearnFree account
Question 17 · Medium
A medical officer explains hepatitis B serology to interns using a patient's chart. Consider these statements: 1. IgM anti-HBc may be the only marker during the window period. 2. HBeAg indicates high infectivity. 3. HBcAg is routinely detected in serum. 4. After vaccination, anti-HBs is present without anti-HBc. Which statements are correct?
1. A1, 2, 3 and 4
2. B1, 2 and 4 only
3. C1 and 2 only
4. D2 and 3 only
Answer and explanation in LearnFree account
Question 18 · Medium
A 30-year-old woman has been on ART for 6 months and attends the ART centre for review. Which test best shows whether her treatment is suppressing the virus?
1. AHIV antibody titre by ELISA
2. Bp24 antigen by rapid test
3. CPlasma HIV-1 RNA viral load
4. DCD4 T-cell count
Answer and explanation in LearnFree account
Question 19 · Medium
A 44-year-old man with multidrug-resistant HIV-1 is being considered for maraviroc. Which test must be done before he starts this drug?
1. AProviral DNA PCR
2. BCD4 percentage by flow cytometry
3. CCo-receptor tropism assay
4. DHLA-B*5701 genotyping
Answer and explanation in LearnFree account
Question 20 · Medium
A 36-year-old man is HBsAg positive on two tests 7 months apart. IgM anti-HBc is negative, IgG anti-HBc is positive, and anti-HBs is negative. He has no symptoms. What is the best interpretation?
1. AChronic hepatitis B infection
2. BAcute hepatitis B infection
3. CVaccine response without infection
4. DResolved infection with immunity
Answer and explanation in LearnFree account
Question 21 · Medium
A 24-year-old man has fever, sore throat, generalised lymph nodes and a rash 3 weeks after unprotected sex with a new partner. A rapid HIV antibody test at the ICTC is non-reactive. Which test is most useful to diagnose HIV infection now?
1. ARepeat rapid antibody test today
2. BHIV-1 RNA by PCR
3. CHIV-1 Western blot
4. DCD4 T-cell count
Answer and explanation in LearnFree account
Question 22 · Medium
A 31-year-old ward attendant in a Lucknow hospital, who has never been vaccinated against hepatitis B, has a needle-stick injury from a patient who is HBsAg positive. What is the best post-exposure plan for hepatitis B?
1. ATenofovir for 28 days
2. BCheck anti-HBs and wait for the result
3. CHBIG and start hepatitis B vaccination
4. DHepatitis B vaccine alone after 6 weeks
Answer and explanation in LearnFree account
Question 23 · Medium
At an ICTC, a 33-year-old woman's sample is reactive on the first and second HIV rapid tests but non-reactive on the third, which uses a different antigen. She is well. How should the result be handled?
1. AReport as HIV positive and start ART on the same day
2. BReport as indeterminate and retest after 2-4 weeks
3. CReport as HIV negative and give no follow-up
4. DRepeat the first test and report its result
Answer and explanation in LearnFree account
Question 24 · Medium
A staff nurse in a Nagpur hospital has a deep hollow-needle injury from a patient who is HBsAg and HBeAg positive, anti-HCV and HCV RNA positive, and HIV positive with a high viral load. The nurse has never been vaccinated against hepatitis B. Which infection does she have the highest risk of acquiring?
1. AHepatitis D
2. BHIV
3. CHepatitis C
4. DHepatitis B
Answer and explanation in LearnFree account
Question 25 · Medium
During a jaundice outbreak in a Bihar town, an 8-year-old boy has fever, vomiting and dark urine. Results: IgM anti-HAV negative, IgG anti-HAV positive, IgM anti-HEV positive, HBsAg negative. What is the best interpretation?
1. AChronic hepatitis E with reactivated HAV
2. BAcute hepatitis E with past hepatitis A
3. CAcute co-infection with HAV and HEV
4. DAcute hepatitis A in the window period
Answer and explanation in LearnFree account

8 more Hepatitis viruses and HIV questions

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Study Microbiology

Hepatitis viruses and HIV

A 9-month-old infant is brought to the ICTC for follow-up. The mother is HIV-positive on ART and is still breastfeeding. A rapid HIV antibody test on the infant is reactive. What is the next step to establish whether the infant is infected?

During an outbreak of jaundice in a Hyderabad colony after sewage leaked into the drinking water pipeline, a 25-year-old woman at 32 weeks of pregnancy develops acute liver failure. Which virus is most likely responsible?

A 32-year-old man newly diagnosed with HIV asks how the virus enters his CD4 T cells. Which viral protein binds the CD4 molecule?

A 50-year-old man with chronic hepatitis C asks why there is still no vaccine for hepatitis C when there is one for hepatitis B. Which property of HCV is the main reason?

A 26-year-old woman had a single high-risk exposure 16 days ago. A third-generation (antibody-only) HIV ELISA is non-reactive, but a fourth-generation test on the same sample is reactive, and later testing confirms infection. Why did the fourth-generation test turn positive earlier?

A 27-year-old primigravida at 16 weeks is HBsAg positive and HBeAg positive on antenatal screening. Her ALT is normal. Which test decides whether she should take tenofovir in the third trimester to protect her baby?

A 10-year-old boy with thalassaemia major in a Gujarat hospital has had monthly transfusions for years, and every donor unit was negative for HBsAg on screening. He now has HBsAg and HBV DNA in his blood. What is the most likely way he acquired HBV?

A 22-year-old college student tested HIV antibody negative at an ICTC 12 days after unprotected sex with a casual partner. She is relieved and asks whether she can stop worrying. What should the counsellor advise?

A 30-year-old pregnant woman is HBsAg positive. Her obstetrician also orders HBeAg, which is positive. What does a positive HBeAg chiefly indicate?

A 28-year-old man donates blood at a regional blood centre. His HIV antibody ELISA is non-reactive, but he seroconverts 4 weeks later after a high-risk exposure that occurred a week before donation. What term describes the period in which he was infected but antibody-negative?

A 29-year-old resident pricks her finger while suturing a patient who is HBsAg positive. She completed hepatitis B vaccination as an intern, and her anti-HBs then was 120 mIU/mL. What hepatitis B prophylaxis does she need?

A 42-year-old man on haemodialysis in Chennai is found to be anti-HCV positive on routine screening. HCV RNA by PCR, repeated twice a month apart, is not detected, and his ALT is normal. What is the best interpretation?

A 38-year-old woman with chronic hepatitis B is started on tenofovir. Tenofovir acts on HBV because the virus replicates its DNA genome through which enzyme?

A 30-year-old woman has been on ART for 6 months and attends the ART centre for review. Which test best shows whether her treatment is suppressing the virus?

A 44-year-old man with multidrug-resistant HIV-1 is being considered for maraviroc. Which test must be done before he starts this drug?

A 36-year-old man is HBsAg positive on two tests 7 months apart. IgM anti-HBc is negative, IgG anti-HBc is positive, and anti-HBs is negative. He has no symptoms. What is the best interpretation?

A 24-year-old man has fever, sore throat, generalised lymph nodes and a rash 3 weeks after unprotected sex with a new partner. A rapid HIV antibody test at the ICTC is non-reactive. Which test is most useful to diagnose HIV infection now?

A 31-year-old ward attendant in a Lucknow hospital, who has never been vaccinated against hepatitis B, has a needle-stick injury from a patient who is HBsAg positive. What is the best post-exposure plan for hepatitis B?

At an ICTC, a 33-year-old woman's sample is reactive on the first and second HIV rapid tests but non-reactive on the third, which uses a different antigen. She is well. How should the result be handled?

During a jaundice outbreak in a Bihar town, an 8-year-old boy has fever, vomiting and dark urine. Results: IgM anti-HAV negative, IgG anti-HAV positive, IgM anti-HEV positive, HBsAg negative. What is the best interpretation?