hepatitis D virus hepatitis
Last reviewed 01/2018
The delta agent is a small, RNA particle that is coated with HBsAg. It is a viroid which is incapable of replication without co-existent HBV infection. HDV suppresses the expression of HBV DNA and causes ongoing or progressive liver disease.
HDV is most common in Southern Europe, the Balkans, Middle East, South India and parts of Africa.
HDV is transmitted by blood. It can affect all of the risk groups for HBV. It is most strongly associated with IV drug abuse and is infrequent among homosexuals. Up to 10% of HBV carriers have anti-HDV antibodies. HDV infection can be reactivated by HIV infection.
Co-infection with HDV and HBV rarely leads to chronic disease but fulminant hepatitis is more likely than with HBV alone.
Superinfection of a chronic carrier of HBV with HDV worsens the prognosis:
- acute hepatitis is likely in a previously healthy carrier
- mild hepatitis may become fulminant
- there is an increased risk of chronic progressive disease, often terminating in cirrhosis
HBsAg carriers with delta agent have a reduced risk of hepatocellular carcinoma. This may be due to inhibition of hepatitis B or to rapid progression of the disease so that death occurs before cancer develops.
Treatment - high dose alpha interferon has been successful in normalising serum aminotransferase levels and clearance of hepatitis delta virus RNA from serum in some patients.
Prevention of HDV infection is by ensuring hepatitis B vaccination in patients at risk.