Hepatitis B surface antigen in hepatitis B half-pair test is positive, which indicates infection with hepatitis B virus. Hepatitis B is an infectious disease caused by the hepatitis B virus, which manifests symptoms such as pain in the liver area and fatigue, etc. Clinical diagnosis is confirmed through the testing of hepatitis B surface antigen and other indicators, and after diagnosis, interferon, lamivudine and famciclovir can be taken for treatment. Hepatitis B surface antigen is the outer shell protein of the hepatitis B virus. If this indicator is positive in the hepatitis B two half-day test, it indicates the presence of the hepatitis B virus in the body, and you may suffer from hepatitis B disease. A positive Hepatitis B Surface Antigen in the Hepatitis B 2.5 test indicates the presence of Hepatitis B virus and the possibility of Hepatitis B disease. It is recommended that additional tests be performed to confirm the diagnosis under the guidance of a doctor.