The Source of Hepatitis B Virus Transmission and Hepatitis B Immunization in Children

Abstract

Hepatitis B Virus Transmission and Hepatitis B Immunization in Children Hepatitis B virus (HBV), a major cause of chronic hepatitis and cirrhosis and, in many societies, an important factor in the development of hepatocellular carcinoma, is found worldwide, but its prevalence and predominant mode of transmission vary among geographic regions. Transmission of HBV is widely recognised to follow perinatal, parenteral, or sexual exposure. In addition, horizontal transmission of the virus (ie, that occurring without apparent perinatal, parenteral, or sexual exposure) is common in areas endemic for the virus. It occurs especially in pre-adolescent children. The World Health Organization (WHO) has endorsed the inclusion of hepatitis B vaccine in routine childhood immunization programs, especially in areas where hepatitis B is endemic. This suggestion prompted a change to a threefold strategy to reduce rates of HBV infection: prevention of mother-to-infant transmission; routine immunization of infants; and "catch-up" immunization of children, adolescent, and high-risk adults not previously immunized.