Risk of transmission associated with sharing drug injecting paraphernalia: analysis of recent hepatitis C virus (HCV) infection using cross-sectional survey data.

Sharing injecting paraphernalia (containers, filters and water) poses a risk of transmitting the hepatitis C virus (HCV). The prevalence of, and risk of HCV from, such behaviour has not been extensively reported in Europe. People who inject drugs (PWID) were recruited in cross-sectional surveys from services providing sterile injecting equipment across Scotland between 2008 and 2010. Participants completed a questionnaire and provided a blood spot for anonymous testing. Logistic regression was used to examine the association between recent HCV infection (anti-HCV negative and HCV-RNA positive) and self-reported measures of injecting equipment sharing in the 6 months preceding interview. Twelve per cent of the sample reported sharing needles/syringes, and 40% reported sharing paraphernalia in the previous 6 months. The adjusted odds ratios (AOR) for sharing needles/syringes (+/- paraphernalia), and sharing only paraphernalia in the last 6 months were 6.7 (95% CI 2.6-17.1) and 3.0 (95% CI 1.2-7.5), respectively. Among those who reported not sharing needles/syringes, sharing containers and filters were both significantly associated with recent HCV infection (AOR 3.1, 95% CI 1.3-7.8 and 3.1, 95% CI 1.3-7.5, respectively); sharing water was not. We present the first study to apply a cross-sectional approach to the analysis of the association between sharing paraphernalia and incident HCV infection and demonstrate consistent results with previous longitudinal studies. The prevalence of paraphernalia sharing in our study population is high, representing significant potential for HCV transmission.