Transmission
Transmission of hepatitis B virus results from exposure to infectious blood or body fluids containing blood. Possible forms of transmission include sexual contact,[44] blood transfusions and transfusion with other human blood products,[45] re-use of contaminated needles and syringes,[46] and vertical transmission from mother to child (MTCT) during childbirth. Without intervention, a mother who is positive for HBsAg confers a 20% risk of passing the infection to her offspring at the time of birth. This risk is as high as 90% if the mother is also positive for HBeAg. HBV can be transmitted between family members within households, possibly by contact of nonintact skin or mucous membrane with secretions or saliva containing HBV.However, at least 30% of reported hepatitis B among adults cannot be associated with an identifiable risk factor.[49] And Shi et al. showed that breastfeeding after proper immunoprophylaxis did not contribute to MTCT of HBV.作者: coolnz 时间: 2012-12-19 23:22:12