Hepatitis B markers

Clinical significance
Hepatitis B virus (HBV) is endemic worldwide and is the main cause of liver disease. HBV is transmitted through direct contact with blood or other body fluids. The most common routes of transmission include blood transfusions, needlestick injuries, direct contact with open wounds, sexual intercourse and transmission from mother to baby at birth.
The average incubation period of HBV infection is 6 to 8 weeks (range: 1 to 6 months). The most common clinical symptoms include general malaise, fever, gastroenteritis and jaundice. HBV infection can typically cause icteric hepatitis, subclinical anicteric hepatitis, fulminant hepatitis or chronic persistent hepatitis. In adults, 90-95% of people with HBV infection recover completely from the acute illness and show no further trace of the virus. About
5-10% of patients with HBV become chronic carriers. About 90% of babies infected with HBV develop chronic hepatitis B infection. It is estimated that more than 300 million people worldwide are chronic carriers of the virus. HBV infection, especially if chronic, is significantly associated with the development of hepatocellular carcinoma.
The serum can be tested for the surface protein s (HBsAg, also called Australia antigen) and the corresponding antibodies (HBsAb), and for the e protein (HBeAg) and the corresponding HBeAb antibodies. The core protein c cannot be measured, only the corresponding antibodies, either total (HBcAb) or only those of class M (HBcAb IgM); the latter may, rarely, be the only sign of a recent or current infection in the so-called serological window, when neither HBsAg nor HBsAb can be detected (the first because it is disappearing, the second because they have not yet appeared). The appearance of HBsAb marks serological recovery.