Hepatitis B virus (HBV) is a bloodborne and sexually transmitted virus. Rates of new infection and acute disease are highest among adults, but chronic infection is more likely to occur in persons infected as infants or young children. Before hepatitis B vaccination programs became routine in the United States, an estimated 30% to 40% of chronic infections are believed to have resulted from perinatal or early childhood transmission, even though less than 10% of reported cases of hepatitis B occurred in children less than 10 years of age. Chronically infected persons are at increased lifetime risk for cirrhosis and hepatocellular carcinoma, and also serve as the main reservoir for continued HBV transmission. Hepatitis B vaccination is the most effective measure to prevent HBV infection and its consequences. Since they were first issued in 1982, recommendations for hepatitis B vaccination have evolved into a comprehensive strategy to eliminate HBV transmission in the United States. To date, the immunization strategy has been implemented with considerable success. Hepatitis B vaccine has been successfully integrated into the childhood vaccine schedule, and infant vaccine coverage levels are now equivalent to those of other vaccines in the childhood schedule. During 1990 to 2004, incidence of acute hepatitis B in the United States declined 75%, with the greatest decline (94%) occurring among children and adolescents. Challenges remain; only approximately 50% of expected births to HBsAg-positive women are identified for case management. There is a need for proper management of women without prenatal care, including HBsAg testing at the time of admission for delivery and administration of the first dose of vaccine to infants less than 12 hours after birth.
(Source: Morbidity and Mortality Weekly Report, December 23, 2005, Centers for Disease Control and Prevention)
