Hepatitis D must you have co-infection with which hepatitis?

• A. Hepatitis B
• B. Hepatitis C
• C. Hepatitis A
• D. Hepatitis E

Answer: (A)

Hepatitis D relies on Hepatitis B to infect. It is a defective virus that cannot form its outer envelope on its own and uses the Hepatitis B surface antigen (HBsAg) produced during HBV infection to assemble and enter liver cells. Because of this dependency, Hepatitis D can only occur in people who have Hepatitis B—either as a simultaneous co-infection or as a superinfection in someone with chronic HBV. The other hepatitis viruses (A, C, E) do not provide the necessary envelope, so they aren’t the co-infecting partner for HDV. Vaccination against Hepatitis B protects against Hepatitis D as well.