A 20-year-old male presented with jaundice for the past 2 weeks. His liver function tests revealed serum bilirubin to be 0.9 mg/dL, SGOT/SGPT to be 1240/ 1450 IU. He was found to be positive for HBsAg and IgM anti-HEY antibodies and negative for IgM anti-c. The most likely diagnosis is –

**Core Concept:** Viral hepatitis is a group of infectious diseases caused by hepatitis viruses (e.g., HBV, HCV, HDV, and HEV). Hepatitis B can be acute or chronic, and acute hepatitis B is characterized by elevated liver enzymes (SGOT/SGPT) and jaundice. The presence of HBsAg and IgM anti-HBc antibodies indicates acute hepatitis B infection.

**Why the Correct Answer is Right:** The patient presents with jaundice, elevated liver enzymes, and positive HBsAg and IgM anti-HBc antibodies. IgM anti-HEY antibodies are seen in acute hepatitis E virus (HEV) infection. Since the patient is negative for IgM anti-HEV, the most likely diagnosis is acute hepatitis B (HBV), which shares similar clinical features with hepatitis E.

**Why Each Wrong Option is Incorrect:**

A. Hepatitis C (HCV) typically presents with different laboratory findings, such as elevated ALT instead of SGOT/SGPT and usually has a chronic course.

B. Hepatitis D (HDV) shares some features with HBV but is rarely seen in endemic areas like India. Moreover, the patient is positive for HBsAg, not HDAg.

C. Hepatitis E (HEV) would have IgM anti-HEV antibodies present, not IgM anti-HEY.

**Clinical Pearl:** The correct diagnosis of viral hepatitis requires a thorough understanding of the clinical, laboratory, and serological findings. In endemic areas like India, it is essential to differentiate between HBV and HDV by assessing HBsAg and HDAg, and between HBV and HEV by assessing IgM anti-HEV and IgM anti-HEY. Prompt treatment can prevent complications like liver cirrhosis and hepatocellular carcinoma.

✓ Correct Answer: B. Superinfection of hepatitis E virus with chronic hepatitis B infection