A 34-year-old man presents with 5 days of malaise, nausea, and dark urine. Total bilirubin is 6 mg/dL, ALT is 1450 U/L, and alkaline phosphatase is normal. Which single test best confirms the etiology?
- A Hepatitis B surface antigen
- B Anti-hepatitis E virus IgG
- C Anti-hepatitis A virus IgM ✓
- D Anti-hepatitis C virus antibody
Correct answer: C. Anti-hepatitis A virus IgM
Explanation
Acute hepatitis C is confirmed by anti-HAV IgM, which appears at symptom onset and persists 3 to 6 months. Anti-HAV IgG indicates past infection or vaccination and does not diagnose acute disease. Anti-HCV may be falsely negative early in acute infection, and HBsAg alone cannot distinguish acute from chronic carriage without anti-HBc IgM.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.