Prevalence and correlates of indirect sharing practices among young adult injection drug users in five U.S. cities

Background: Sharing of drug paraphernalia to prepare, measure and divide drugs for injection remains an important residual risk factor for hepatitis C and other blood-borne infections among injection drug users (IDUs) especially as sharing of syringes for injection decreases. Methods: We analyzed data from five U.S. cities to determine the prevalence and independent correlates of non-syringe paraphernalia-sharing (NSPS) and syringe-mediated drug-splitting (SMDS) among 15-30-year-old IDUs who reported not injecting with others' used syringes (receptive syringe-sharing, RSS). Results: NSPS was reported by 54% of IDUs who did not practice RSS and was independently associated (p < 0.05) with having ≥5 injection partners, injecting with sex partners or regular injection partners, injecting in shooting galleries, peers' sharing behaviors, lower self-efficacy for avoiding NSPS, and less knowledge of HIV and HCV transmission. SMDS was reported by 26% of IDUs who did not practice RSS, and was independently associated with having ≥5 injection partners, injecting in shooting galleries, and inversely associated with unknown HIV status. Conclusions: NSPS and SMDS were common among young adult IDUs. Increased efforts to prevent these risky practices should address social and environmental contexts of injection and incorporate knowledge and skills building, self-efficacy, and peer norms.