Sharing of Injection Drug Preparation Equipment Is Associated With HIV Infection: A Cross-sectional Study

Background: Sharing needles/syringes and sexual transmission are widely appreciated as means of HIV transmission among persons who inject drugs (PWIDs). London, Canada, is experiencing an outbreak of HIV among PWIDs, despite a large needle/syringe distribution program and low rates of needle/syringe sharing. Objective: To determine whether sharing of injection drug preparation equipment (IDPE) is associated with HIV infection. Methods: Between August 2016 and June 2017, individuals with a history of injection drug use and residence in London were recruited to complete a comprehensive questionnaire and HIV testing. Results: A total of 127 participants were recruited; 8 were excluded because of failure to complete HIV testing. The remaining 35 HIV-infected (cases) and 84 HIV-uninfected (controls) participants were assessed. Regression analysis found that sharing IDPE, without sharing needles/syringes, was strongly associated with HIV infection (adjusted odds ratio: 22.1, 95% confidence interval: 4.51 to 108.6, P < 0.001). Conclusions: Sharing of IDPE is a risk factor for HIV infection among PWIDs, even in the absence of needle/syringe sharing. Harm reduction interventions to reduce HIV transmission associated with this practice are urgently needed.