MI4.7-9 | Viral Hepatitis — Summary & Reflection

REFLECT

A physician receives a hepatitis serology report from a 35-year-old asymptomatic health worker: HBsAg negative, anti-HBs 8 mIU/mL, anti-HBc IgG positive. The lab marks anti-HBs as 'non-protective' (<10 mIU/mL). How do you interpret this pattern? Was this person vaccinated, naturally infected, or both? Does this person need a booster dose, and if so, how many? What does anti-HBc positivity with no HBsAg tell you about their current infection status?

KEY TAKEAWAYS

Key takeaways from this SDL:

1. Five hepatitis viruses: A and E are faeco-oral, self-limiting; B, C, D are parenteral, with chronicity risk (HCV highest at 70–85%).
2. HEV in pregnancy: 20–25% case fatality in third trimester; most important acute hepatitis in Indian flood outbreaks.
3. HBV serological panel:
- HBsAg = infection (acute or chronic)
- Anti-HBs = immunity
- Anti-HBc IgM = acute infection / window period marker
- HBeAg = active replication / high infectivity
- Anti-HBe = seroconversion (good sign)
4. Window period: HBsAg cleared, anti-HBs not yet appeared; anti-HBc IgM is the only diagnostic marker.
5. Vaccination: Recombinant HBsAg; generates anti-HBs only (no anti-HBc); protective if ≥10 mIU/mL; birth dose critical.
6. HCV: 70–85% chronicity; no vaccine; DAAs (sofosbuvir-based) cure >95%; genotype 3 prevalent in India.
7. HDV: Defective virus, needs HBV; super-infection accelerates cirrhosis; HBV vaccine prevents.