I. Mother-to-child transmission About 1/3 (about 30 million) of hepatitis B surface antigen carriers are from mother-to-child transmission. More than 90% of them develop chronic infection. HBsAg (hepatitis B surface antigen) positivity, especially HBsAg and HBeAg (hepatitis B e antigen) double-positive (i.e., major triple-positive) mothers, is highly infectious. Hepatitis B virus is mainly transmitted through the following channels: (1) Intrauterine transmission. It is mainly transmitted through the placenta. (2) Intrauterine infection. This means that the newborn is infected by inhalation of maternal blood, amniotic fluid and vaginal secretions containing hepatitis B virus during delivery; it may also be infected through the newborn’s broken skin or mucous membranes. The newborn can be effectively prevented by hepatitis B vaccine combined with hepatitis B immunoglobulin injection after birth. (3) Postnatal infection. Newborns can also be infected through close contact with their mothers. The combination of hepatitis B vaccine and hepatitis B immunoglobulin for newborns can effectively interrupt this infection. Hepatitis B virus is mainly found in the blood of patients, so transmission through blood is also an important way. (1) Daily contact: exposure of broken skin or mucous membrane to body fluids or secretions containing blood; sharing razors, toothbrushes, tattoos and eyebrows; intravenous drug use, etc. (2) Medical transmission: such as: blood transfusion or use of blood products, hemodialysis, accidental stabbing by needles or scalpels (inadequate sterilization of instruments), dental fillings, etc. (3) Sexual contact transmission The semen or vaginal secretions of hepatitis B surface antigen carriers are infectious. Especially when the sexual partner does not have protective hepatitis B surface antibodies, a slight break in the skin or mucous membrane during sexual intercourse can easily infect each other. The best way to prevent this is still to give normal people who are not yet infected with the hepatitis B virus a full course of hepatitis B vaccine so that they can develop protective hepatitis B surface antibodies. The rate of transmission is even higher with multiple partners, a history of sexually transmitted diseases, and anal sex. Here is a special reminder to prevent the tendency to expand the transmission route of hepatitis B virus and eliminate discrimination against hepatitis B virus carriers or hepatitis B patients: 1. If there is no breakage of the skin or mucous membrane of the lips on the body surface, kissing will not spread, shaking hands and hugging will not spread. 2. Hepatitis B virus is transmitted through blood, not through the digestive tract (gastrointestinal tract), so sharing meals and eating utensils will not spread. 3. Hepatitis B virus is not transmitted through the respiratory tract, so coughing and sneezing will not spread.