Hepatitis B and C are mainly blood-borne, followed by the transmission of certain body fluids of the human body. 1, blood transfusion, blood products; the input of blood without formal testing and informal production of plasma, blood cells, globulin, albumin, clotting factors, etc., is can cause blood transfusion, transfusion of blood products after the hepatitis B or C. 2, unclean interventional medical devices stabbing injuries, such as syringe needles, not sterilized for continuous multi-person use, often occurring in rural areas. Blood collection needles, acupuncture needles are not disinfected for continuous use, endoscopes such as colonoscopes are not disinfected for continuous multi-person use, can make more than one person’s blood exchange through new wounds causing new transmission, new infections. 3, perinatal transmission of hepatitis B virus from mother to child: this transmission is directly related to blood, hepatitis B virus surface antigen-positive pregnant women, especially e antigen-positive pregnant women, in the process of delivery is easy to pass the hepatitis B virus to the newborn baby. What is meant by perinatal period? Perinatal transmission occurs between the seventh month of pregnancy and three weeks after delivery, when the hepatitis B virus infects the fetus or newborn baby. Perinatal transmission occurs mainly during labor and delivery, and the rate of perinatal transmission is 80-90% in HBSAg and HBeAg-positive mothers. However, because the proportion of double-positive mothers among surface antigen-positive mothers is only 30%, the average number of surface antigen-positive mothers per 100 pregnant women in China is 8 × 0.3 = 2.4 (2.4 double-positive mothers). According to the perinatal transmission rate of 90% for double-positive mothers, 2.4×0.9=2.16 which means that the perinatal mother-to-child transmission rate is about 2.16/100 mothers, among these 2.16 people, including intrauterine transmission, the longest incubation period of hepatitis B is 6 months, so the calculation of perinatal transmission is appropriate according to the rate of HBsAg positivity in newborns full 7 months of age, perinatal transmission is the mother-to-child transmission The HBsAg of infants after 7 months of age should be the mother-to-child transmission in life cannot be confused with perinatal transmission of hepatitis C is not serious. 4, sexual transmission includes male, male, male and female behavior. Male behavior is the worst, surface antigen carriers have hepatitis B virus in their semen, vaginal secretions have hepatitis B virus, the process of sexual intercourse is easy to cause the genital mucosa breakage virus take the opportunity to enter causing infection, the anal membrane is thin is not the normal conduit for sexual intercourse, extremely vulnerable to injury. It is very easy to be infected and the use of condoms should be promoted. This transmission belongs to body fluids plus blood. 5, intravenous drug users, often a syringe we take turns injecting, blood exchange, the most vulnerable to infection B, C hepatitis, especially hepatitis C transmission in the most serious intravenous drug users. 6, certain risk factors in life, and blood exchange, such as sharing razors, sharing toothbrushes, sharing towels, tattoos, eyebrow tattoo, ear piercing, nose piercing, ring auricle, etc., due to the uncleanliness of the knife caused by mutual transmission, but the bite of mosquitoes can not cause transmission, because some people have done research, mosquitoes without hepatitis B virus reproduction, mosquito bites without stomach contents spit out, mosquito breeding season and non-mosquito breeding season with Hepatitis B virus with the rate of high and low irrelevant. In addition, shaking hands, kissing, eating together, working together, eating together in a common dormitory, a lot of epidemiological work to prove that there is no risk of transmission.