Paper II — 2024 December (Supplementary) (2019 Scheme) — Q3
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Paper II
2024 December (Supplementary) (2019 Scheme) · 100 marks · 180 min
Question
A 30 year old female was brought to the hospital with complaints of loss of weight and appetite of
3 months duration. On examination, she was jaundiced and hepatomegaly present. she gave a history of
blood transfusion in the past. Lab investigation showed she was HBsAg positive.
(a) What is the most probable clinical diagnosis. 1 mark(s)
(b) What are the different modes of transmission of this agent. 2 mark(s)
(c) Discuss the laboratory diagnosis of this infection. 5 mark(s)
(d) Add a note on the immunoprophylaxis. 2 mark(s)
Q310 marksEssays
Answer
(a) Most probable clinical diagnosis: Hepatitis B virus (HBV) infection — likely transfusion-transmitted, given weight loss/anorexia, jaundice, hepatomegaly, a history of blood transfusion, and positive HBsAg.
(b) Modes of transmission: Parenteral/blood-borne route — transfusion of infected blood/blood products (as in this patient), unsafe injection practices, needle-stick exposure; Sexual transmission; and Perinatal (vertical) transmission from an infected mother to her infant during childbirth (the most important route globally in high-endemicity regions).
(c) Laboratory diagnosis:
HBsAg (surface antigen) — the first marker to appear; indicates current infection (acute or chronic); persistence beyond 6 months defines a chronic carrier state, as suspected in this patient.
IgM anti-HBc — indicates recent/acute infection (the “core window” marker), positive even when HBsAg has become undetectable during the window period.
IgG anti-HBc — indicates past exposure (resolved infection or ongoing chronic infection), persists lifelong.
HBeAg — marker of active viral replication and high infectivity.
Anti-HBe — appears with seroconversion, generally indicating reduced viral replication.
Anti-HBs — indicates recovery/immunity (from past resolved infection or successful vaccination).
HBV DNA (viral load) — direct marker of viral replication, used for monitoring and guiding antiviral therapy.
Liver function tests — elevated ALT/AST, bilirubin, assessing hepatocellular injury.
Liver biopsy/non-invasive fibrosis assessment — to stage chronic liver disease if chronicity is confirmed.
(d) Immunoprophylaxis:
Active immunization — Hepatitis B vaccine (a recombinant HBsAg subunit vaccine), given as part of the routine infant immunization schedule (including a birth dose), and available for at-risk adults/healthcare workers; induces protective anti-HBs antibody.
Passive immunization — Hepatitis B Immunoglobulin (HBIG), providing immediate passive protection, indicated for post-exposure prophylaxis (e.g., needle-stick injury in a susceptible individual, ideally combined with vaccine initiation within 24–48 hours, and no later than 7 days, of exposure) and for neonates born to HBsAg-positive mothers (given within 12–24 hours of birth, alongside the birth dose of vaccine, to prevent perinatal transmission).
