Childhood hepatitis B virus infections in the United States before hepatitis B immunization

Objective. To estimate the number of hepatitis B virus (HBV) infections amo ng US children younger than 10 years before implementation of routine child hood hepatitis B immunization. Methods. Incidence of HBV infection in children was modeled from existing p revalence data by means of regression analysis. Sources of data for the mod els included published and unpublished surveys that determined the prevalen ce of HBV infection in US-born children. The number of nonperinatal HBV inf ections in children younger than 10 years was estimated by applying these i nfection rates to 1991 population data according to maternal race, ethnicit y, and birthplace. Results. Estimated annual rates of infection ranged from 24 per 100 000 in non-Asian children to 2580 per 100 000 in children of Southeast Asian immig rant mothers. These rates indicate that by the early 1990s, HBV was infecti ng 16 000 children who were younger than 10 years (8700 non-Asian children and 7300 Asian-American children) annually. The total estimate, not includi ng perinatal infections, ranged from 12 000 (95% confidence interval: 5500- 27 700) to 24 900 (95% confidence interval: 16 700-42 300) infections and d epended on how the estimated rates were applied to the population data. Conclusion. Thousands of US children were infected each year with HBV befor e routine infant hepatitis B immunization, placing them at high risk of dea th from cirrhosis or hepatocellular carcinoma later in life.