Which form of hepatitis is caused by a DNA virus?

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

Answer: (A)

Hepatitis B is caused by a DNA virus. Its genome is a circular, partially double-stranded DNA molecule. During replication it uses an RNA intermediate and reverse transcriptase, which is a hallmark that makes it distinct from the other hepatitis viruses. The others are RNA viruses: hepatitis A and E are non-enveloped positive-sense RNA viruses, hepatitis C is an enveloped positive-sense RNA virus, and hepatitis D is an RNA virus that requires hepatitis B surface antigen to complete its life cycle. Thus, the virus with a DNA genome among these forms is hepatitis B.