Hepatitis B virus (HBV) is one of the major global public health problems.  HBV genotypes D and A are prevalent in India and genotype D has a less favourable prognosis than genotype A. The natural course of chronic HBV infection can be divided into immune-tolerant phase, immune clearance phase, and residual or inactive phase. HBV reactivation and relapse of hepatitis may occur in some patients who are in the residual or inactive phase. Initial evaluation, diagnostic modalities and decision to treat need to be individualised. Major treatment modalities include interferon and nucleoside analogues including lamivudine, adefovir, entecavir and tenofovir. Therapy differs in special populations like pregnant women, patients with cirrhosis, and in cases of co-infection with HIV or hepatitis C virus.

Key words: viral hepatitis, chronic hepatitis, hepatitis B virus, antiviral agents, lamivudine, interferons.