Influence of occult hepatitis B virus infection in chronic hepatitis C outcomes

Persistence of hepatitis B virus-DNA in the sera,peripheral blood mononuclear cells or in the liver of hepatitis B surface antigen(HBsAg) -negative patients with or without serological markers of previous exposure(antibodies to HBsAg and/or to HB-core antigen) defines the entity called occult hepatitis B infection(OBI).Co-infection with hepatitis B and hepatitis C viruses is frequent in highly endemic areas.While this co-infection increases the risk of liver disease progression,development of cirrhosis and hepatocellular carcinoma and also increases the rate of therapeutic failure to interferon-based treatments than either virus alone,a potentially negative effect of OBI on clinical outcomes and of therapeutic response to current antiviral regimes of patients with chronic hepatitis C remains inconclusive.