Hepatitis B is a viral infection. Symptoms are loss of appetite, nausea and abdominal discomfort, followed within a few days by jaundice. The course of illness is usually 4 weeks, and rarely, it can be fatal. About 5% of adults remains carriers after acute infection, which can lead to liver cirrhosis and liver cancer after 15-20 years. Children under 1 year of age usually have no symptoms, but virtually 100% will become chronic carriers.
Hepatitis B is particularly high in Asia, Africa and South America. The incidence ranges from 7% to 20% and the attack rate for Hepatitis B per journey is 60/100,000 in Asia to 20/100,000 in Africa.
Hepatitis B is primarily transmitted through activities which result in exchange of blood or blood-derived fluids, and through sexual activities, either heterosexual or homosexual with a carrier. Principal activities which may result in blood exposure include work in health care, receipt of blood transfusion which have not been screened for Hepatitis B, having medical or dental work done using inadequate sterilised equipment. In addition, in less developed areas, open wound and skin lesions due to factors such as impetigo, scabies and scratched insect bites may play a role in disease transmission if direct exposure to wounds occurs.