Paper II — 2025 March (Supplementary (SAY)) (2019 Scheme) — Q14
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Paper II
2025 March (Supplementary (SAY)) (2019 Scheme) · 100 marks · 180 min
Question
Hepatitis C virus- modes of transmission and laboratory diagnosis. (2+2)
Q144 marksShort Answers
Answer
Modes of transmission of Hepatitis C virus (HCV): predominantly parenteral (historically transfusion-associated, now dominantly injection drug use/needle-sharing in most settings), with sexual transmission and vertical (mother-to-child) transmission occurring but considerably less efficiently than with Hepatitis B virus.
Laboratory diagnosis:
Anti-HCV antibody (screening ELISA) — the initial screening test; a positive result indicates past or present infection but does not by itself confirm active/ongoing infection, since antibody persists even after viral clearance.
HCV RNA (RT-PCR, qualitative or quantitative) — confirms active, ongoing infection by directly detecting circulating viral RNA, distinguishing active infection from a resolved past infection (where antibody persists but the virus has cleared); quantitative PCR (viral load) also guides and monitors antiviral treatment response.
HCV genotyping — determines the specific HCV genotype, relevant for treatment regimen selection.
Liver function tests — elevated ALT/AST support ongoing hepatocellular injury, though non-specific.
Typical diagnostic algorithm: anti-HCV antibody screening → if reactive, confirm active infection with HCV RNA PCR.
