Which statement correctly describes the virological basis of hepatitis D virus infection?
- A It is a faecally transmitted RNA virus that replicates independently in hepatocytes
- B It is a defective virus that requires HBsAg for its assembly and entry into hepatocytes ✓
- C It is a DNA virus closely related to hepatitis B and prevented by the hepatitis B vaccine alone through cross-immunity
- D It establishes chronic infection only when acquired as co-infection with hepatitis B, never as superinfection
Correct answer: B. It is a defective virus that requires HBsAg for its assembly and entry into hepatocytes
Explanation
Hepatitis D virus is a defective circular RNA virus whose outer envelope consists of HBsAg supplied by hepatitis B virus, so it can infect and assemble only in HBsAg-positive hosts. Superinfection of a chronic hepatitis B carrier actually carries a higher risk of fulminant hepatitis and chronic delta infection than co-infection, which rules out option D. The hepatitis B vaccine prevents delta infection indirectly by preventing HBV carriage.
Reference: Park's Textbook of Preventive and Social Medicine, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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