A. General knowledge of hepatitis B: Hepatitis B “two and a half” is a popular term, generally speaking from the medical academic, strictly called hepatitis B antigen antibody system test. The hepatitis B two-and-a-half is the most common serum marker used in domestic hospitals to check for infection with the hepatitis B virus (HBV). The Hepatitis B 5 tests, also known as the Hepatitis B 2.5, include Hepatitis B surface antigen (expressed as HBsAg), Hepatitis B surface antibody (expressed as anti-HBS), e antigen (expressed as HBeAg), e antibody (expressed as anti-HBe), and core antibody (expressed as anti-HBc). The Hepatitis B 5 test is a serological marker that detects the hepatitis B virus in the blood by drawing venous blood from the patient. It is also known as the “Hepatitis B Five”. Because the hepatitis B “two pairs of half” the people can easily grasp, the people are also used to follow a piece called “big three yang”, “small three yang”, “two pairs of half “This is a common name for the public, but it is not allowed to be written in medical cases. Two and a half refers to the five items, the first pair refers to have surface antigen and surface antibody. The second pair is the E antigen and E antibody. The “half” refers to the core antibody. The hepatitis B two-and-a-half is mainly a response to whether the body is infected with the hepatitis B virus, to fully understand the infection, to match the HBV-DNA test, so as to better reflect the real virus replication in the body. Second, the significance of hepatitis B two to half test: 1, the first positive, the remaining four negative. This hepatitis B five test results indicate the latent period of acute hepatitis B virus infection late; 2, the fifth positive, the remaining four negative. This indicates that the person is a latent carrier of hepatitis B virus or is in the window period of infection, and also indicates that he has been infected with hepatitis B virus; 3. The first three items are positive, and the remaining three items are negative. This hepatitis B five test result indicates an early stage of acute hepatitis B; 4. The first and fifth items are positive and the remaining three are negative. This hepatitis B test result indicates that the person has been infected with the hepatitis B virus and is recovering; 5. The first, third and fifth items are positive and the remaining two are negative. Commonly known as “major tri-positive”, this hepatitis B five results indicate acute and chronic hepatitis B; 6, the first, fourth, five positive, the remaining two negative. Commonly known as “small tri-positive”, indicating acute and chronic hepatitis B; 7. The fourth and fifth positive items, the remaining three negative items. The five hepatitis B results indicate a recovery period of acute hepatitis B virus infection or previous hepatitis B virus infection; 8, the second, fourth, five positive, the remaining two negative. It indicates a recovery period of hepatitis B with existing immunity; 9. The second and fifth positive items and the remaining three negative items. This hepatitis B five results indicate that it is after the hepatitis B vaccination, or the hepatitis B virus infection has been recovered and there is already immunity.