RESUMEN
Questionnaire data from almost 12,000 street-recruited drug injectors in 19 cities were analyzed to determine racial differences that may affect transmission of the human immunodeficiency virus (HIV). Self-reported sexual behaviors of drug injectors differ by city-type. White male drug injectors reported less unprotected vaginal sex than black or Latino males in multicultural--black/white/Mexican-origin and biracial cities. Black drug users of both sexes were less likely than white or Latino drug users to report unprotected and sex in multicultural--black/white/Mexican-origin and multicultural--black/white/Puerto Rican cities. The reported percentage of sex acts in which a condom was used was similar for black, white, and Puerto Rican men, and for black and white women, in all city types, but Puerto Rican women reported more condom use than black women. Mexican-origin drug injectors of each gender were least likely to report using condoms in multicultural--black/white/Mexican-origin cities. Black drug injectors are particularly likely to report having sex partners who do not inject drugs, as are Puerto Rican men and as are whites in multicultural--black/white/Mexican-origin cities. High-risk sex without condoms is widely reported among all groups of drug injectors studied: Each racial/gender group in each city-type averaged 15 or more episodes of unprotected vaginal sex per month, and 10% of most subgroups report having anal sex within the past 6 months. At least 45% of subjects in each city-type reported sex with noninjectors of the opposite gender. Without continued and expanded intervention, these data are consistent with HIV spreading to drug injectors, their sexual partners, and their future children, in all racial/ethnic groups.