A 5-year-old child presents with fever, jaundice, and elevated liver enzymes. His mother reports that two other children at his daycare have similar symptoms. Which serological marker is most specific for acute hepatitis A virus infection?
- A Anti-HAV IgG
- B HAV RNA in stool
- C Anti-HAV IgM ✓
- D HAV antigen in serum
Correct answer: C. Anti-HAV IgM
Explanation
Anti-HAV IgM appears early in acute infection and is the serological marker of choice for diagnosing acute hepatitis A. Anti-HAV IgG indicates past infection or vaccination and persists for life, so it cannot distinguish acute from prior infection. While HAV RNA in stool is present during infection, it is not routinely used for diagnosis. HAV antigen detection is not a standard diagnostic test.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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