Paper II
2018 July (Supplementary) (2010 Scheme) · 40 marks · 120 min

Question

Lab. diagnosis of hepatitis B infection

Q102 marksShort Notes

Answer

Laboratory diagnosis of Hepatitis B virus (HBV) infection relies on serological markers:

  • HBsAg — first marker, indicates current infection (chronic if >6 months).
  • Anti-HBs — indicates recovery with immunity, or successful vaccination.
  • IgM anti-HBc — indicates recent/acute infection; key marker during the “window period.”
  • IgG anti-HBc — persists long-term, indicating past/current infection (absent after vaccination).
  • HBeAg — marker of active viral replication and high infectivity.
  • Anti-HBe — appearance generally indicates reduced replication/infectivity.
  • HBV DNA (quantitative PCR) — most direct marker of active replication, used for monitoring.

Typical patterns: acute infection — HBsAg+, IgM anti-HBc+; window period — only IgM anti-HBc positive; chronic infection — HBsAg+ (>6 months), IgG anti-HBc+; resolved infection — anti-HBs+, IgG anti-HBc+; vaccinated — anti-HBs+ only.

Other Years Asked


Revise MBBS
Preview