Hepatitis B

Hepatitis B is a viral infection that can cause serious or even fatal damage to the liver. The word hepatitis literally means inflammation of the liver. Hepatitis B is caused by the hepatitis B virus, also known as HBV.

HBV is most common in China, south-east Asia and sub-Saharan Africa, where between 10 and 20% of the population may have been infected with hepatitis B. In western Europe and the United States, 0.1 to 0.2% of the population are infected with the hepatitis B virus.

Hepatitis B is usually transmitted through contact with blood, semen, vaginal fluids or saliva of a hepatitis B virus-infected person. Transmission of hepatitis B virus from mother to infant causes the majority of infections worldwide, but the availability of vaccination has virtually eradicated mother-to-child transmission of hepatitis B virus in developed countries.

In western Europe, the United States and Australia, hepatitis B infection occurs predominantly among gay and bisexual men, people who share drug injecting equipment, and healthcare workers. Screening of donated blood has dramatically decreased hepatitis B infection among haemophiliacs and other blood product recipients. The virus is many times more infectious than HIV.

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.