Two chapters describe the evolving nature of the epidemic and the range of prevention activities that are being implemented to retard the spread of HIV in the U.S. population. Three chapters review domains of particular interest: the ways in which HIV infection is affecting adolescents and female prostitutes and the challenge of protecting the blood supply while ensuring the adequacy of that supply. The final chapter reviews factors that affect the quality of data collected in surveys of AIDS-related behaviors. Overall, the study finds that the broadening scope of the AIDS epidemic calls for increased prevention efforts that will reach a variety of subpopulations at differential risk such as adults and adolescents, men and women, homosexuals, and heterosexuals. Of particular concern is the finding that HIV is spreading disproportionately among minority subpopulations. Recommendations pertain to research on the spread of AIDS in subpopulations at high risk; prevention efforts that target these high risk groups; transmission behaviors; and accurate, expanded, and relevant data collection. Chapter references, appended data, and a subject index