Working Towards the Elimination of Perinatal Hepatitis B Infection
Hepatitis B virus (HBV) infection is a serious illness in the newborn and young infant. The virus, first discovered in the mid-1960s, is transmitted through percutaneous (i.e., puncture through skin) or mucosal (i.e., direct contact with mucous membranes) exposure to infectious blood or body fluids. The virus is highly infectious, can be transmitted in the absence of visible blood, and remains viable on environmental surfaces for at least seven days. Once the virus enters the body, it is transported to the liver where it replicates. Although one generally thinks of the acute illness as a self-limited one in the adult with characteristic signs and symptoms, HBV infection in the infant is almost exclusively asymptomatic and hence, unrecognized. The devastating aspect of the infection is that the infant and young child frequently fail to clear the virus, and the illness becomes chronic. As many as 80-90% of infected infants progress to chronic infection, and chronically infected persons as adults are at increased risk of cirrhosis, hepatocellular carcinoma, and liver failure with approximately 25% dying from these serious complications.
Before 1982, an estimated 200,000-300,000 persons in the U.S. alone were infected with HBV annually, including approximately 20,000 infants. No effective pre-exposure prophylaxis existed, and only post-exposure prophylaxis in the form of hepatitis B immune globulin (HBIG) was available. However, the first hepatitis B vaccine was approved in the United States in 1981 and proved to be a real game changer. The availability of the vaccine set the stage for remarkable progress in the elimination of HBV infection among all age groups. With the advent of an effective vaccine, incurable hepatitis B infection had become preventable. The vaccine saves lives!