Hepatitis D infection is most commonly seen in individuals with a history of exposure to which risk factor?

• A. Intravenous drug use
• B. Travel to endemic areas
• C. Unprotected sex
• D. Seafood consumption

Answer: (A)

Hepatitis D virus can only replicate in the presence of hepatitis B virus, so it shares the same transmission routes as HBV—primarily blood-borne exposure and sexual contact. The strongest and most direct risk factor for HDV is parenteral exposure, such as sharing needles for intravenous drug use, which brings infected blood into contact with another person and enables HDV transmission along with HBV. While travel to endemic areas or unprotected sex can increase risk by boosting HBV exposure, intravenous drug use most clearly explains the higher likelihood of HDV infection in many settings. Seafood consumption has no role in transmitting HBV or HDV.