Blumberg antigen

The Blumberg antigen, also known as the hepatitis B surface antigen (HBsAg), is a protein found on the surface of the hepatitis B virus. Its presence in the blood indicates an active hepatitis B infection, either ongoing or recently acquired. Detecting this antigen is important for diagnosing infection, assessing contagiousness, and monitoring treatment. It can be present before symptoms appear and remain during the infectious period, making it a key marker in hepatitis B management.