Hepatitis B and D

Hepatitis B virus (HBV) infection is a global health problem. About 400 million people are chronically infected with HBV, which is a major cause of liver cirrhosis and liver failure. The global distribution has changed due to migration. Immunization programs have resulted in a dramatic decline in the incidence and prevalence of HBV and hepatitis D virus (HDV) infection in many countries. Host immune responses to the viruses define the clinical course of infection, which varies from an asymptomatic carrier state to fulminant hepatic failure. The timing of treatment and the choice of antiviral therapy depend on the patient profile. The main goal of antiviral therapy is to prevent liver cirrhosis. Antiviral treatment can suppress HBV to undetectable levels. However, the HBV genome can persist in hepatocytes despite sustained and potent suppression. HDV requires co-existing HBV for its proliferation. Around 20 million people are co-infected with HDV and HBV. In general, HBV/HDV co-infection causes more severe liver disease than is observed in HBV alone. Interferon is the current accepted treatment option of HBV/HDV infection, though treatment results are disappointing. For selected patients with decompensated liver cirrhosis due to HBV or HBV/HDV infection, liver transplantation may be appropriate.