Source Health Protection Scotland, NHS National Services Scotland, Meridian Court, 5 Cadogan Street, Glasgow G2 6QU, UK.
Hepatitis B virus (HBV) infection is a major cause of morbidity and mortality worldwide. Chronic hepatitis B (CHB) infection is associated with an increased risk of cirrhosis, hepatic decompensation and hepatocellular carcinoma (HCC). The likelihood of developing CHB is related to the age at which infection is acquired; the risk being lowest in adults and >90% in neonates whose mothers are hepatitis B e antigen positive. Treatment of CHB infection aims to clear HBV DNA and prevent the development of complications.
There are currently seven drugs available for the treatment of CHB: five nucleos(t)ide analogues and two interferon-based therapies. Long-term treatment is often required, and the decision to treat is based on clinical assessment including the phase of CHB infection and the presence and extent of liver damage. A safe and effective HBV vaccine has been available since the early 1980s. Vaccination plays a central role in HBV prevention strategies worldwide, and a decline in the incidence and prevalence of HBV infection following the introduction of universal HBV vaccination programmes has been observed in many countries including the USA and parts of South East Asia and Europe. Post-exposure prophylaxis (PEP) with HBV vaccine +/- hepatitis B immunoglobulin is highly effective in preventing mother to child transmission and in preventing transmission following sharps injuries, sexual contact and other exposures to infected blood and body fluids. Transmission of HBV in the health care setting has become an increasingly rare event in developed nations.
However, it remains a significant risk in developing countries reflecting the higher prevalence of CHB, limited access to HBV vaccination and PEP and a lack of adherence to standard infection control precautions.