The hepatitis B virus is a major cause of serious, life-threatening liver disease, including liver cancer and cirrhosis (scarring of the liver caused by long-term liver damage).
In 2017 the World Health Organization (WHO) estimated that around 250 million people worldwide were chronically infected with hepatitis B virus. In areas such as sub-Saharan Africa, most of Asia and the Pacific islands, 10% or more of the population have chronic hepatitis B infection.
The UK has generally low levels of hepatitis B disease, but there is variation between different parts of the country. Because of the risk to newborn babies, since 1998 there has been a screening programme for pregnant women in the UK. Overall, about 4 in 1000 pregnant women in the UK are found to be infected with hepatitis B, but in areas such as inner cities the rates may be much higher than this.