According to projections, needle-sharing will cause 60,000 new HIV infections in the coming year. Law enforcement personnel could reduce that number by cracking down on retail-level heroin dealing, closing "shooting galleries," and stopping the practice of arresting heroin users for possession of injection equipment. Between 250 and 2500 people annually are exposed to HIV through prostitution. Recommendations for reducing this risk include increased enforcement activity, mandatory HIV testing of convicted prostitutes and heroin possessors, and greater penalties against identified HIV-carriers who practice prostitution. Prison sex, including rape, will cause approximately 1800 infections per year; needle-sharing in prison will add to this total. Additional precautions and sanctions against prison rape and segregation of HIV-infected inmates could reduce the number of transmissions. 37 footnotes.