Abstract
Comparing drug-injecting risk between cities that differ in the legality of sterile syringe distribution for injection drug use provides a natural experiment to assess the efficacy of legalizing sterile syringe distribution as a structural intervention to prevent human immunodeficiency virus (HIV) and other parenterally transmitted infections among injection drug users (IDUs). This study compares the parenteral risk for HIV and hepatitis B (HBV) and C (HCV) infection among IDUs in Newark, NJ, USA, where syringe distribution programs were illegal during the period when data were collected, and New York City (NYC) where they were legal. IDUs were nontreatment recruited, 2004-2006, serotested, and interviewed about syringe sources and injecting risk behaviors (prior 30 days). In multivariate logistic regression, adjusted odds ratios (AOR) and 95% confidence intervals (95% CI) for city differences are estimated controlling for potential city confounders. IDUs in Newark (n = 214) vs. NYC (n = 312) were more likely to test seropositive for HIV (26% vs. 5%; AOR = 3.2; 95% CI = 1.6, 6.1), antibody to the HBV core antigen (70% vs. 27%; AOR = 4.4; 95% CI = 2.8, 6.9), and antibody to HCV (82% vs. 53%; AOR = 3.0; 95% CI = 1.8, 4.9), were less likely to obtain syringes from syringe exchange programs or pharmacies (AOR = 0.004; 95% CI = 0.001, 0.01), and were more likely to obtain syringes from street sellers (AOR = 74.0; 95% CI = 29.9, 183.2), to inject with another IDU's used syringe (AOR = 2.3; 95% CI = 1.1, 5.0), to reuse syringes (AOR = 2.99; 95% CI = 1.63, 5.50), and to not always inject once only with a new, sterile syringe that had been sealed in a wrapper (AOR = 5.4; 95% CI = 2.9, 10.3). In localities where sterile syringe distribution is illegal, IDUs are more likely to obtain syringes from unsafe sources and to engage in injecting risk behaviors. Legalizing and rapidly implementing sterile syringe distribution programs are critical for reducing parenterally transmitted HIV, HBV, and HCV among IDUs.