Hepatitis B is a disease caused by the hepatitis B virus (HBV), which can lead to abnormal liver function, liver failure, cirrhosis or liver cancer and other adverse consequences, and requires regular diagnosis and treatment. What are the ways of transmission of hepatitis B? Transmission through blood or blood products; mother-to-child transmission; through broken skin and mucous membranes; sexual contact. The level of contagiousness depends on the level of hepatitis B virus DNA quantification. Hepatitis B is not usually transmitted by daily work or life contact. How can I prevent hepatitis B? Hepatitis B can be prevented by receiving the hepatitis B vaccine. After the first dose, the second dose is given 1 month later and the third dose is given 6 months later. To interrupt mother-to-child transmission, hepatitis B immunoglobulin and hepatitis B vaccine should be given to newborns within 12 hours of birth, with a 90% success rate. Which patients need antiviral treatment? The following two conditions are also met: 1. Hepatitis B DNA quantification ≥ 105copies/ml (2×104 IU/ml) in e antigen (HBeAg) positive patients and ≥ 104copies/ml (2000 IU/ml) in e antigen (HBeAg) negative patients; 2. Glutathione aminotransferase (ALT) ≥ 2 times the upper limit of normal value. What are the benefits of antiviral therapy? Antiviral therapy can inhibit viral replication, slow down the progression of liver damage, reduce the chance of cirrhosis or liver cancer, reduce infectiousness, and promote normalization of liver function. However, antiviral therapy is not yet able to cure hepatitis B, nor can it completely eliminate the occurrence of cirrhosis or liver cancer. What drugs are available for antiviral treatment? Nucleoside (acid) analogues: The advantages are that the side effects are generally mild and few, and they are administered orally; the disadvantages are that the course of treatment is long, there are problems of drug resistance, and some patients have rebound after stopping the drug. Currently, lamivudine (Herceptin), adefovir (Hovalix), entecavir (Boludin), and telbivudine (Sulbivir) are commonly used. Interferon: The advantage is that the treatment course is fixed and there is about 8% conversion rate of surface antigen (HBsAg), the disadvantage is that it needs to be administered by injection and there are many adverse effects (including flu-like symptoms, bone marrow suppression, psychiatric symptoms, induction of autoantibodies, etc.). PEGylated interferon alpha-2a (Pyroxin) is commonly used. How long does the course of antiviral therapy need to be? Nucleoside (acid) analogues: e antigen (HBeAg) positive patients should be treated until HBeAg serology is converted (commonly known as “major triplet” to “minor triplet”) and maintained for more than 1 year; HBeAg negative patients should be treated until Hepatitis B DNA is negative and HBeAg-negative patients can stop taking the drug under close monitoring until their Hepatitis B DNA is negative and their transaminases are normal for more than 1.5 years. At present, a long course of treatment is mostly advocated, and there are risks in stopping the drug. Interferon: usually one year.