Abstract Hepatitis B is endemic in many African, Asian and Pacific countries causing much debilitation and death. The disease can lead to chronic cirrhosis and is closely associated with liver cell cancer. There are in the order of 200 million people that carry the virus and constitute a huge reservoir of infection. This latent infection and the combination of a long incubation period (20–180 days), together with the increasing volume and speed of international travel have contributed to make this disease a serious health problem in non-endemic areas. At particular risk are medical and para-medical staff in contract with human blood (especially those concerned with haemodialysis units), dentists, homosexuals, haemophiliacs, patients and staff in mental hospitals and recipients of blood transfusions or other blood products.