Hepatitis D

By Howard J. Worman, M. D.

The Hepatitis D virus (also called delta virus) is a small circular RNA virus. The Hepatitis D virus is replication defective and therefore cannot propagate in the absence of another virus. In humans, Hepatitis D virus infection only occurs in the presence of Hepatitis B infection.

Hepatitis D virus infection is transmitted by blood and blood products.

The risk factors for infection are similar to those for Hepatitis B virus infection. The Hepatitis D virus most often infects intravenous drug users.

A patient can acquire Hepatitis D virus infection at the same time as he/she is infected with the Hepatitis B virus. This is called co-infection. A patient with Hepatitis B can be infected with Hepatitis D virus at any time after acute Hepatitis B virus infection. This is called super-infection.

Hepatitis D virus super- infection should be suspected in a patient with chronic Hepatitis B whose condition suddenly worsens. There is usually an obvious history of continued exposure to blood or blood products (eg. an active intravenous drug user). A particularly aggressive acute Hepatitis B infection could suggest Hepatitis D co- infection. Co-infection or super-infection with Hepatitis D virus in a patient with Hepatitis B is diagnosed by the presence of antibodies against the Hepatitis D virus. IgM antibodies indicate acute infection.

Interferon-alpha is used to treat patients with chronic Hepatitis B and Hepatitis D infection. Some studies have suggested that a dose higher than that usually used for Hepatitis B infection may be beneficial.

Copyright, 1995, Columbia University Division of Gastroenterology
Hepatitis D/Howard J. Worman, M.D./hjw14@columbia.edu