HCV serostatus and injection sharing practices among those who obtain syringes from pharmacies and directly and indirectly from syringe services programs in rural New England

Abstract

Abstract Background Among people who inject drugs (PWID), obtaining syringes via syringe services programs (SSPs) and pharmacies reduces injection sharing practices associated with hepatitis C virus (HCV). Whether indirect use of SSPs via secondary exchange confers a similar benefit remains unknown, particularly in rural settings. We compared HCV serostatus and injection sharing practices by primary syringe source among a sample of rural PWID. Methods Data are from a cross-sectional study of adults who use drugs recruited from eleven rural counties in New Hampshire, Vermont, and Massachusetts using respondent-driven sampling (2018–2019). Study staff performed HCV antibody testing. An audio computer-assisted self-interview assessed sociodemographic characteristics, past 30-day injection practices, and past 30-day primary syringe source. Primary syringe source was classified as direct SSP, pharmacy, indirect SSP (secondary exchange), or “other” (friend/acquaintance, street seller, partner/relative, found them). Mixed effects modified Poisson models assessed the association of primary syringe source with HCV seroprevalence and injection sharing practices. Results Among 397 PWID, the most common primary syringe source was “other” (33%), then pharmacies (27%), SSPs (22%), and secondary exchange (18%). In multivariable models, compared with those obtaining most syringes from “other” sources, those obtaining most syringes from pharmacies had a lower HCV seroprevalence [adjusted prevalence ratio (APR):0.85, 95% confidence interval (CI) 0.73–0.9985]; however, the upper bound of the 95% CI was close to 1.0. Compared with those obtaining most syringes from other sources, PWID obtaining most syringes directly from SSPs or pharmacies were less likely to report borrowing used syringes [APR(SSP):0.60, 95% CI 0.43–0.85 and APR(Pharmacies):0.70, 95% CI 0.52–0.93], borrowing used injection equipment [APR(SSP):0.59, 95% CI 0.50–0.69 and APR (Pharmacies):0.81, 95% CI 0.68–0.98], and backloading [APR(SSP):0.65, 95% CI 0.48–0.88 and APR(Pharmacies):0.78, 95% CI 0.67–0.91]. Potential inverse associations between obtaining most syringes via secondary exchange and injection sharing practices did not reach the threshold for statistical significance. Conclusions PWID in rural New England largely relied on informal syringe sources (i.e., secondary exchange or sources besides SSPs/pharmacies). Those obtaining most syringes from an SSP or pharmacy were less likely to share injection equipment/syringes and had a lower HCV seroprevalence, which suggests using these sources reduces the risk of new HCV infections or serves as proxy for past injection behavior.