What are the main ways to spread hepatitis B virus? 1.Transmission through blood: it is the most important way of transmission, such as transfusion of whole blood, plasma, serum or other blood products, and transmission through blood-borne injection. Experiments have proved that as long as a very small amount of blood containing hepatitis B virus, it can cause hepatitis B transmission. 2.Medical transmission: If the medical equipment is contaminated by hepatitis B virus and then not sterilized thoroughly or handled improperly, it can cause transmission; hemodialysis patients are often the target of hepatitis B transmission. Fetal transmission: such as the vertical transmission of hepatitis B virus from pregnant women to their newborns through the birth canal, and the infection of the fetus by pregnant women with hepatitis in the late stage of pregnancy. 4, sexual contact transmission: in recent years, foreign reports on sexual promiscuity, homosexuality and heterosexuality observation is sure that the sexual transmission of hepatitis B is an important way of infection of sexual partners, and this kind of transmission also includes the transmission between husband and wife in the family. 5, insect bite transmission: in the tropical and subtropical mosquitoes and various blood-sucking insects, may play a role in the transmission of hepatitis B. The transmission of hepatitis B is also a major cause of the spread of the disease. 6, life close contact transmission: with hepatitis B patients or virus carriers long-term close contact, saliva, urine, blood, bile and milk, can be contaminated utensils, objects, through the broken skin, mucous membranes and transmission of hepatitis B. The mouth-to-mouth transmission may be the most important. Among them, mouth-to-mouth transmission may be the most important way. This is because hepatitis B virus surface antigen can be detected in the saliva of acute and chronic hepatitis and virus carriers.