Prevention of HIV infection in street-recruited injection drug users

Background: Injection drug users (IDUs) and their sex partners account for an increasing proportion of new AIDS and HIV cases in the United States, bu t public debate and policy regarding the effectiveness of various HIV preve ntion programs for them must cite data from other countries, from non-stree t-recruited IDUs already in treatment, or other programs, and from infectio n rates for pathogens other than HIV. Methods: Participants were recruited from the street at six sites (Baltimor e [Maryland], New York [two sites], Chicago [Illinois], San Jose [Californi a], Los Angeles [California], and at a state women's correctional facility [Connecticut]), interviewed with a standard questionnaire, and located and reinterviewed at one or more follow-up visits (mean, 7.8 months later). HIV serostatus and participation in various programs and behaviors that could reduce HIV infection risk were determined at each visit. Results: In all, 3773 participants were recruited from the street, and 2306 (61%) were located and interviewed subsequently. Of 3562 initial serum spe cimens, 520 (14.6%) were HIV-seropositive; at subsequent assessment, 19 peo ple, all from the East Coast and Chicago, had acquired HIV. Not using previ ously used needles was substantially protective against HIV acquisition (re lative risk [RR], 0.29; 95% confidence interval [CI], 0.11-0.80) and, in a multivariate model, was significantly associated with use of needle and syr inge exchange programs (adjusted odds ratio [ORadj], 2.08; 95% CI, 1.15-3.8 5). Similarly, reduction of injection frequency was very protective against seroconversion (RR, 0.33; 95% CI, 0.14-0.80), and this behavior was strong ly associated with participation in drug treatment programs (ORadj, 3.54; 9 5% CI, 2.50-5.00). In a separate analysis, only 37.5% of study-participants had sufficient new needles to meet their monthly demand. Conclusions: In this large multicity study of IDUs in the United States, se veral HIV prevention strategies appeared to be individually and partially e ffective; these results indicate the continued need for, and substantial ga ps in, effective approaches to preventing HIV infection in drug users.