[Hepatitis B: epidemiology, natural history, biology, treatment monitoring]

Hepatitis B virus (HBV) infection is a worldwide public health problem. In France, 150,000 individuals are infected with the HBV. Although many are asymptomatic carriers, about 30% have chronic hepatitis, a condition associated with a risk of cirrhosis and hepatocellular carcinoma. Antiviral treatments, most notably interferon alpha, probably modify the natural history of hepatitis B, decreasing the risk of hepatocellular carcinoma and increasing survival. Nucleoside analogs, particularly lamivudine, have also demonstrated potent antiviral activity, which should however be weighed against the increasing risk over time of mutation development in the YMDD region of the DNA polymerase reverse transcriptase. Antiviral therapy monitoring should include clinical safety evaluations and periodic laboratory tests including blood cell counts, transaminase activities, and serum DNA levels. The improving results provided by antiviral drugs should not deflect attention away from the importance of large-scale hepatitis B immunization of neonates, which has been shown to decrease the incidence of hepatocellular carcinoma in areas with high levels of hepatitis B endemicity.