Abstract
OBJECTIVES: This study was designed to assess and compare sex risk behaviors for human immunodeficiency virus (HIV) transmission of three drug user groups: injectors who do not smoke crack, crack smokers who do not inject, and injectors who also smoke crack. METHODS: Sexual risk behaviors for HIV were assessed among 246 drug users from Denver, Miami, and San Francisco. Respondents were classified into the three drug groups based on self-report and verified through urinalysis and physical inspection. RESULTS: An increased risk for HIV through sexual transmission was associated with crack cocaine use, particularly among those who also injected. Crack smoking injectors were more likely to report sex with an injector, exchanging sex for drugs and/or money, drug use before or during sex, and unprotected sexual intercourse. They also injected more than injectors only, smoked crack as often as smokers only, and reported higher overall frequencies of drug use. CONCLUSIONS: These findings, together with the higher rates of gonorrhea and syphilis reported by smokers and injectors/smokers, are indicators of the risk crack poses for the heterosexual transmission of HIV.