Abstract
Since 1985, cases of hepatitis B virus infection attributable to heterosexual activity have increased by 38%, whereas those attributable to homosexual activity have declined by 62%, Heterosexual activity now accounts for 26% of cases and has replaced homosexual activity in importance as a risk factor for hepatitis B. For heterosexuals, the number of recent (ie, in the preceding four to six months) and lifetime sex partners, as well as a history of other sexually transmitted diseases (eg. syphilis) appear to be significantly associated with increased hepatitis B virus infection. Of equal concern is the rising number of cases among parenteral drug users in the United States and some minority groups, including blacks, Hispanics and Asians. Hepatitis B prevention by administering hepatitis B vaccine to high risk groups before exposure to infection has not been successful, and at least 30% of hepatitis B cases in the United States have no identifiable risk factors. Thus, participation in the current programs which target only high risk groups is not possible. The ideal immunization strategy is integration of hepatitis B vaccine in to the routine childhood immunization schedule.