Hepatitis B is caused by a virus (HBV) that leads to an inflammation of the liver. Severe outcomes may be observed following acute hepatitis, but they mainly result from the complications of chronic HBV infection (e.g., liver cirrhosis and cancer).
Symptoms of hepatitis B
- The incubation period of the hepatitis B virus is 75 days on average, but can vary from 30 to 180 days.
- 1 to 2% of subjects develop fulminant hepatitis B, a total acute necrosis of the liver, for which mortality rate is extremely high.(1-2)
- Following HBV infection, 5% of patients will develop chronic hepatitis (i.e., persistence of HBV in the body) with the potential risk to develop cirrhosis and liver cancer.(2)
- The risk of transition to a chronic state is particularly frequent among immunodepressed individuals and newborns.
Epidemiology and vaccination against hepatitis B
- HBV is transmitted primarily through blood, and to a lesser extent by other body fluids.
- Before the large introduction of vaccination programs, WHO estimated that about two billion people worldwide had been infected with the virus. In 2015, an estimated 887,000 persons died due to the acute or chronic consequences of hepatitis B.(1)
1 - WHO. Hepatitis B Fact sheet. Updated July 2017, accessed January 2018. http://www.who.int/mediacentre/factsheets/fs204/en/index.html
2 - The Pink Book 13th ed. CDC. Hepatitis B. Epidemiology and Prevention of Vaccine-Preventable Diseases. April 2015; p. 149-173. https://www.cdc.gov/vaccines/pubs/pinkbook/hepb.html