[World-wide epidemiology of hepatitis B]

Hepatitis B is one of the major infectious diseases of mankind with 350,000,000 chronic carriers at high risk of death from cirrhosis and primary liver cancer. The probability of becoming a chronic HBV carrier following infection depends primarily on age, and ranges from 70% following mother to child transmission to less than 10% following adult infection. The world is conceptually divided into regions of high, intermediate, and low endemicity, with predominant modes of transmission differing by region. In Asia and Africa, most transmission occurs among children, whereas in Western Europe and North America most transmission occurs during early adult life due to lifestyle, occupational exposures, or exposures within ethnic groups where the virus is endemic.