Objective.-To estimate the number of persons infected with the human immunodeficiency virus (HIV) living in the United States and the change in HIV infection prevalence since 1984. Design.-We estimated HIV prevalence from 3 data sources. We estimated past HIV infection rates from a statistical procedure based on national acquired immunodeficiency syndrome (AIDS) case surveillance data and estimates of the time from HIV infection to AIDS diagnosis. We also analyzed HIV prevalence data from 2 national surveys, a survey of childbearing women and a household survey of current health status. We used other data sources to adjust these survey estimates to include groups not covered in the surveys. Results.-Approximately 0.3% of US residents (650 000-900 000 persons) were infected with HIV in 1992, Approximately 0.6% of men (including adolescent boys greater than or equal to 13 years of age) were infected, including approximately 2% of non-Hispanic black men and 1% of Hispanic men, Approximately 0.1% of women (including adolescent girls greater than or equal to 13 years of age) were infected, including approximately 0.6% of non-Hispanic black women. Approximately half of all infected persons were men who had sex with men, and one fourth were injecting drug users. The prevalence of HIV infection increased from 1984 to 1992, with a greater relative increase among women than men. Conclusions.-The 3 different data sources and methods are consistent in estimating that 650 000 to 900 000 persons were infected with HIV in the United States in 1992. Among adolescents and adults of both sexes, the proportion infected was substantially higher among non-Hispanic blacks and Hispanics than among non-Hispanic whites, HIV-related illness will be a major clinical and public health problem in the United States for years to come.
