Hepatitis D is a single stranded RNA virus that is transmitted parenterally. It is an incomplete RNA virus that requires hepatitis B surface antigen to complete its replication and transmission cycle.

It is transmitted in a similar fashion to hepatitis B (exchange of bodily fluids) and patients may be infected with hepatitis B and hepatitis D at the same time.

Hepatitis D terminology:

• Co-infection: Hepatitis B and Hepatitis D infection at the same time.
• Superinfection: A hepatitis B surface antigen positive patient subsequently develops a hepatitis D infection.
  • Hepatitis D superinfection is an differential for chronic hepatitis B patients with acute flare up

Superinfection is associated with high risk of fulminant hepatitis, chronic hepatitis status and cirrhosis.

Diagnosis is made via reverse polymerase chain reaction of hepatitis D RNA.

Interferon is currently used as treatment, but with a poor evidence base.