Hepatitis B virus (HBV) infection remains a global public health problem despite the availability of an effective vaccine.
An overview of HBV infection in children will be presented here. More detailed discussions of the microbiology, pathogenesis, clinical manifestations, and diagnosis are presented separately. (See "Characteristics of the hepatitis B virus and pathogenesis of infection" and "Clinical manifestations and natural history of hepatitis B virus infection" and "Serologic diagnosis of hepatitis B virus infection".)
In the United States, the incidence of acute hepatitis B in children (<19 years) has decreased from approximately 13.8 cases per 100,000 population (10 to 19 years) in the 1980s  to 3.03 and 0.34 cases per 100,000 population in 1990 and 2002, respectively . Declines have been greatest among children who were born after 1991 when recommendations for universal hepatitis B vaccination of infants were implemented. By 2007, the incidence of acute hepatitis B in children <15 years had fallen to 0.02 cases per 100,000 population [3,4]. (See "Hepatitis B virus vaccination".)
Most cases of acute hepatitis B infection in the United States, and in several other non-endemic countries, develop in patients from high-risk groups such as intravenous drug users, homosexual men, in those living in communities with a large proportion of immigrants from regions where HBV is endemic, and in certain groups where HBV is endemic, such as Native Americans in Alaska . The majority of children with chronic HBV infections are immigrants, have immigrant parents, or became exposed through other household contacts .
In countries where HBV is endemic, perinatal transmission remains the most important cause of chronic infection because of high rates of disease in pregnant women. Perinatal transmission also occurs in non-endemic countries, including the United States, mostly in children of HBV-infected mothers who do not receive appropriate HBV immunoprophylaxis at birth [7,8]. (See "Epidemiology, transmission, and prevention of hepatitis B virus infection" and "Clinical significance of hepatitis B virus genotypes".)