Incidence and risk factors for acute hepatitis B in the United States, 1982-1998: implications for vaccination programs.

From 1982-1998, enhanced sentinel surveillance for acute hepatitis B was conducted in 4 counties in the United States to determine trends in disease incidence and risk factors for infection. During this period, the reported incidence of acute hepatitis B declined by 76.1% from 13.8 cases per 100,000 in 1987 to 3.3 cases per 100,000 in 1998. Cases associated with injection drug use (IDU) decreased by 90.6%, men who have sex with men (MSM) by 63.5%, and heterosexual activity by 50.7%. During 1994-1998, the most commonly reported risk factor for infection was high-risk heterosexual activity (39.8%) followed by MSM activity (14.6%) and IDU (13.8%). Over half of all patients (55.5%) reported treatment for a sexually transmitted disease (STD) or incarceration in a prison or jail prior to their illness, suggesting that more than half of the acute hepatitis B cases might have been prevented through routine hepatitis B immunization in STD clinics and correctional health care programs.