HIV prevalence and associated factors among injection drug users in Baltimore: Insight for continued prevention efforts

Background: Injection drug users (IDUs) remain a population of great concern for HIV infection and transmission. Methods: The Baltimore National HIV Behavioral Surveillance Project (BESURE) examined HIV prevalence and associated risk factors among a sample of IDUs recruited using respondent driven sampling (RDS). Analyses were adjusted for RDS sampling design and were limited to those 539 IDUs who completed a quantitative survey and HIV test. Results: Sample HIV prevalence was 12%. Population HIV prevalence was estimated at 7.7 (95% CI: 5.0, 12.0), 12.0 (95% CI: 5.4, 24.3) among those over 45, 10.0 (95% CI: 5.6, 18.1) among African-Americans, 3.3 (95% CI: 1.3, 5.4) among Whites, and 34.2 (95% CI: 3.6, 64.3) among MSM-IDUs. In adjusted analyses, HIV infection was significantly associated with being African-American, older age, condom use, recent STI, and sharing injection equipment other than syringes. Approximately half of HIV-positive and negative respondents reported sharing syringes in the past year and about 25% of both groups reported always using sterile syringes. Conclusion: Racial disparities in HIV infection persist among Baltimore IDUs. Rates of injection risk were high, but there was strong evidence of risk reduction efforts. Results point to a need for continued HIV prevention efforts for IDUs in Baltimore, particularly among MSM-IDU, and offer insight into priority areas for prevention for positives.