It is now recognized that there are five areas: first mother-to-child transmission. “The concept of bodily fluids includes saliva, tears, sweat, breast milk, semen, endocrine fluid, blood, all of which belong to the body’s bodily fluids, as long as the bodily fluids contain the hepatitis B virus, it is infectious. Mother to child transmission includes two aspects, one is vertical transmission, the other is horizontal transmission. People have always thought that mother-to-child transmission is vertical transmission, but it is not. Intrauterine transmission accounts for only 10% of cases, and only 10% of cases are transmitted during pregnancy in the womb during fetal life, which is not very high. The main thing is transmission at the level of close living contact during the perinatal period and after birth. As a mother with a major triplet, the likelihood of her child being infected after birth is 90-95 percent, and the chance of a child born to an E antigen-negative hepatitis B mother being infected is half that of an E antigen-positive child, about 45-40 percent. Second, medical transmission. In the hospital examination and treatment process caused by the use of medical equipment not strictly sterilized and repeated use of HBV-contaminated infection, this is called medical transmission, including surgery, dental equipment, blood collection needles, acupuncture needles and endoscopy, etc.. Thirdly, blood transfusion transmission. Importation of HBV-infected blood and blood products can cause the occurrence of post-transfusion hepatitis B. Fourth close living contact transmission. Including eating together, as long as there is damage to the skin and mucous membranes in life, it is possible to be infected. After the damage to the skin and mucous membranes, the body fluids of hepatitis B patients and then fall on your broken skin and mucous membranes may be infected; can also be used in daily life razor, toothbrush, etc. caused by HBV transmission, which is called close living infection. Fifth sexual transmission. For hepatitis B patients can be transmitted sexually, sexual transmission is also a kind of transmission of body fluids. In addition, kissing can also be transmitted, if the mucous membrane of the mouth and lips is broken also have this possibility. At present, mosquito bites are not recognized as a means of transmission. To the infectious disease hospital to look at the patient, by the mosquito bite on the fear of a little, there is no need.