A 47-year-old man was found to be anti-HCV reactive, with HCV RNA 2.4 × 10^6 IU/mL, at a visa medical 3 years ago, but was never treated. His 5-year-old nephew, who lives with him, had jaundice a month ago. He has now had 6 days of nausea and dark urine and is jaundiced. Results: ALT 2,350 U/L (reference below 40); bilirubin 96 µmol/L (5.6 mg/dL); INR 1.5; IgM anti-HAV reactive; anti-HCV reactive; HCV RNA 1.1 × 10^5 IU/mL; HBsAg nonreactive; IgM anti-HBc nonreactive; IgM anti-HEV nonreactive. The best interpretation is:

Acute hepatitis A in chronic hepatitis C

Acute flare of chronic hepatitis C

Acute hepatitis B in its core window

New acute hepatitis C reinfection

During an outbreak investigation in a hemodialysis unit, a patient whose anti-HCV was nonreactive a month ago now has HCV RNA 85,000 IU/mL, anti-HCV still nonreactive and a new ALT rise to 210 U/L (reference below 40 U/L). What is the best interpretation?

Acute HCV infection before antibody appears

Chronic HCV with loss of the antibody

False-positive HCV RNA; HCV is excluded

Past HCV infection that has resolved

A 45-year-old man has completed 12 weeks of direct-acting antiviral treatment for hepatitis C. Twelve weeks after the end of treatment: HCV RNA not detected, anti-HCV reactive, ALT 28 U/L (reference below 40 U/L). What do these results mean?

Cure, with antibody that will usually persist

Treatment failure, shown by the anti-HCV

Lifelong immunity to HCV reinfection

Low-level infection that will relapse

A baby born to a mother with chronic hepatitis C (HCV RNA detected) is brought for testing at 3 months. Which test shows whether the baby is infected?

HCV RNA by nucleic acid testing

HCV genotype on the mother's sample

Hepatitis A, C and E serology

9 DOH Abu Dhabi (HAAD) lab licensing practice questions on Hepatitis A, C and E serology, part of Immunology and Serology. The first 9 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 47-year-old man was found to be anti-HCV reactive, with HCV RNA 2.4 × 10^6 IU/mL, at a visa medical 3 years ago, but was never treated. His 5-year-old nephew, who lives with him, had jaundice a month ago. He has now had 6 days of nausea and dark urine and is jaundiced. Results: ALT 2,350 U/L (reference below 40); bilirubin 96 µmol/L (5.6 mg/dL); INR 1.5; IgM anti-HAV reactive; anti-HCV reactive; HCV RNA 1.1 × 10^5 IU/mL; HBsAg nonreactive; IgM anti-HBc nonreactive; IgM anti-HEV nonreactive. The best interpretation is:
1. AAcute flare of chronic hepatitis C
2. BAcute hepatitis B in its core window
3. CNew acute hepatitis C reinfection
4. DAcute hepatitis A in chronic hepatitis C
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Answer: D · Acute hepatitis A in chronic hepatitis C
The reactive IgM anti-HAV, with a household contact who had jaundice a month earlier, shows acute hepatitis A. The anti-HCV and HCV RNA documented 3 years ago, without treatment since, show that he also has chronic hepatitis C, and today's anti-HCV and RNA reflect that old infection. Chronic hepatitis C rarely causes an ALT above 2,000 U/L with jaundice, and his HCV RNA is lower than before rather than higher, which does not suggest an HCV flare. Reinfection needs an earlier cure, which never happened, and the core window of hepatitis B would show IgM anti-HBc. People with chronic liver disease, including hepatitis C, should be vaccinated against hepatitis A and B, because acute hepatitis A can be severe in them.
- A: An HCV flare rarely gives an ALT above 2,000 U/L, and his HCV RNA has fallen.
- B: IgM anti-HBc is nonreactive, which excludes the core window.
- C: Reinfection needs an earlier cure; he was never treated.
Question 2 · Hard
During an outbreak investigation in a hemodialysis unit, a patient whose anti-HCV was nonreactive a month ago now has HCV RNA 85,000 IU/mL, anti-HCV still nonreactive and a new ALT rise to 210 U/L (reference below 40 U/L). What is the best interpretation?
1. AAcute HCV infection before antibody appears
2. BChronic HCV with loss of the antibody
3. CFalse-positive HCV RNA; HCV is excluded
4. DPast HCV infection that has resolved
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Answer: A · Acute HCV infection before antibody appears
HCV RNA becomes detectable 1-2 weeks after exposure, while anti-HCV usually takes about 8-11 weeks to appear, and longer in dialysis and immunosuppressed patients. RNA without antibody, plus a new ALT rise, places this patient in the seronegative window of acute infection. Anti-HCV is repeated later to document seroconversion. This is why outbreak and high-risk testing uses HCV RNA, not antibody alone.
- B: Antibody was nonreactive a month ago too, so this is a new infection.
- C: Detectable RNA with a new ALT rise during an outbreak is not a false positive.
- D: Resolved infection shows antibody without RNA, the opposite pattern.
Question 3 · Easy
Which hepatitis virus, spread by the fecal-oral route, carries the highest risk of death for women in the third trimester of pregnancy?
1. AHepatitis C virus
2. BHepatitis E virus
3. CHepatitis B virus
4. DHepatitis A virus
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Answer: B · Hepatitis E virus
Hepatitis E genotypes 1 and 2 spread through fecally contaminated water in parts of Asia and Africa and can cause fulminant hepatitis in late pregnancy, with mortality reported as high as 20-25%. Diagnosis is by IgM anti-HEV, with HEV RNA in blood or stool where available. Hepatitis A spreads the same way but is rarely severe in pregnancy. Hepatitis B and C are bloodborne.
- A: Hepatitis C is bloodborne and rarely causes acute liver failure.
- C: Hepatitis B is spread by blood, sex and birth, not by the fecal-oral route.
- D: Hepatitis A is also fecal-oral but is rarely severe in pregnancy.
Question 4 · Hard
A 45-year-old man has completed 12 weeks of direct-acting antiviral treatment for hepatitis C. Twelve weeks after the end of treatment: HCV RNA not detected, anti-HCV reactive, ALT 28 U/L (reference below 40 U/L). What do these results mean?
1. ATreatment failure, shown by the anti-HCV
2. BCure, with antibody that will usually persist
3. CLifelong immunity to HCV reinfection
4. DLow-level infection that will relapse
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Answer: B · Cure, with antibody that will usually persist
Undetectable HCV RNA 12 weeks after the end of treatment is a sustained virologic response (SVR12), which is accepted as cure. Anti-HCV usually stays reactive for years after cure or spontaneous clearance, so it cannot be used to judge treatment success. The antibody does not protect against new infection, so people at continuing risk are checked with HCV RNA. Late relapse after SVR12 is very rare.
- A: Anti-HCV persists after cure, so it does not show treatment failure.
- C: Anti-HCV is not protective, and reinfection can occur.
- D: Relapse after SVR12 is very rare, and RNA is not detected.
Question 5 · Medium
A baby born to a mother with chronic hepatitis C (HCV RNA detected) is brought for testing at 3 months. Which test shows whether the baby is infected?
1. AHCV RNA by nucleic acid testing
2. BHCV genotype on the mother's sample
3. CAnti-HCV IgM antibody test
4. DAnti-HCV antibody immunoassay
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Answer: A · HCV RNA by nucleic acid testing
Maternal IgG anti-HCV crosses the placenta and can stay detectable in the baby for up to 18 months, so an antibody test before then cannot separate passive antibody from infection. CDC (2023) advises HCV RNA testing at 2-6 months of age for all perinatally exposed infants. If only antibody testing is used, it waits until 18 months, and a reactive result then needs HCV RNA. Most exposed babies are not infected.
- B: The mother's genotype says nothing about whether the baby is infected.
- C: IgM anti-HCV tests are not reliable and are not used for diagnosis.
- D: Maternal IgG anti-HCV can persist in the baby for up to 18 months.
Question 6 · Medium
Where HCV RNA testing is not available, WHO guidance accepts that current infection after a reactive anti-HCV can be shown by testing for:
1. AAnti-HCV IgG avidity
2. BAnti-HCV by a second brand
3. CHCV genotype
4. DHCV core antigen
Answer and explanation in LearnFree account
Question 7 · Hard
A kidney transplant recipient on tacrolimus has had ALT of 150-250 U/L (reference below 40 U/L) for 5 months. Anti-HEV IgM and IgG are nonreactive. HBV and HCV markers, CMV DNA and drug levels give no explanation. Which test is most likely to reveal the cause?
1. AHEV RNA in blood or stool
2. BIgM anti-HAV
3. CAnti-HEV IgG avidity
4. DRepeat anti-HEV IgM in 2 weeks
Answer and explanation in LearnFree account
Question 8 · Hard
A 30-year-old man develops jaundice 5 weeks after returning from a region with poor sanitation. ALT 1,400 U/L (reference below 40 U/L). IgM anti-HAV nonreactive, total anti-HAV reactive, HBsAg nonreactive, IgM anti-HBc nonreactive, anti-HCV nonreactive, IgM anti-HEV reactive. The most likely diagnosis is:
1. AAcute hepatitis E, with past hepatitis A immunity
2. BAcute hepatitis B in the core window period
3. CAcute hepatitis C before antibody appears
4. DAcute hepatitis A, with HEV cross-reactivity
Answer and explanation in LearnFree account
Question 9 · Medium
A patient's HCV antibody test is reactive. What is the next step to confirm current infection?
1. ARepeat the antibody test in one year
2. BArrange a liver biopsy
3. CTest for HCV RNA (PCR)
4. DTest for anti-HBc
Answer and explanation in LearnFree account

Hepatitis A, C and E serology

During an outbreak investigation in a hemodialysis unit, a patient whose anti-HCV was nonreactive a month ago now has HCV RNA 85,000 IU/mL, anti-HCV still nonreactive and a new ALT rise to 210 U/L (reference below 40 U/L). What is the best interpretation?

Which hepatitis virus, spread by the fecal-oral route, carries the highest risk of death for women in the third trimester of pregnancy?

A 45-year-old man has completed 12 weeks of direct-acting antiviral treatment for hepatitis C. Twelve weeks after the end of treatment: HCV RNA not detected, anti-HCV reactive, ALT 28 U/L (reference below 40 U/L). What do these results mean?

A baby born to a mother with chronic hepatitis C (HCV RNA detected) is brought for testing at 3 months. Which test shows whether the baby is infected?

Where HCV RNA testing is not available, WHO guidance accepts that current infection after a reactive anti-HCV can be shown by testing for:

A kidney transplant recipient on tacrolimus has had ALT of 150-250 U/L (reference below 40 U/L) for 5 months. Anti-HEV IgM and IgG are nonreactive. HBV and HCV markers, CMV DNA and drug levels give no explanation. Which test is most likely to reveal the cause?

A patient's HCV antibody test is reactive. What is the next step to confirm current infection?