title: Incidence of hepatitis C in drug injectors: the role of homelessness, opiate substitution treatment, equipment sharing, and community size.
abstract: A prospective cohort study estimated the incidence of hepatitis C virus (HCV) in drug injectors in South Wales (UK). In total, 286/481 eligible seronegative individuals were followed up after approximately 12 months. Dried blood spot samples were collected and tested for anti-HCV antibody and behavioural data were collected at baseline and follow-up. HCV incidence was 5.9/100 person-years [95% confidence interval (CI) 3.4-9.5]. HCV incidence was predicted by community size [incident rate ratio (IRR) 6.6, 95% CI 2.11-20.51, P = 0.001], homelessness (IRR 2.9, 95% CI 1.02-8.28, P = 0.047) and sharing injecting equipment (IRR 12.7, 95% CI 1.62-99.6, P = 0.015). HCV incidence was reduced in individuals in opiate substitution treatment (IRR 0.34, 95% CI 0.12-0.99, P = 0.047). In order to reduce follow-up bias we used multiple imputation of missing data using switching regression; after imputation estimated HCV incidence was 8.5/100 person-years (95% CI 5.4-12.7). HCV incidence varies with community size, equipment sharing and homelessness are associated with increased HCV incidence and opiate substitution treatment may be protective against HCV.
authors.affiliation: National Public Health Service for Wales, Health Protection Team, Wales, UK. noel.craine@nphs.wales.nhs.uk
authors.forename: N
authors.initials: N
authors.lastname: Craine
authors.forename: M
authors.initials: M
authors.lastname: Hickman
authors.forename: J V
authors.initials: JV
authors.lastname: Parry
authors.forename: J
authors.initials: J
authors.lastname: Smith
authors.forename: A M
authors.initials: AM
authors.lastname: Walker
authors.forename: D
authors.initials: D
authors.lastname: Russell
authors.forename: B
authors.initials: B
authors.lastname: Nix
authors.forename: M
authors.initials: M
authors.lastname: May
authors.forename: T
authors.initials: T
authors.lastname: McDonald
authors.forename: M
authors.initials: M
authors.lastname: Lyons
mesh_terms: D000328:Adult; D005260:Female; D019698:Hepatitis C, Chronic / Q000453:epidemiology*; D006703:Ill-Housed Persons; D006801:Humans; D015994:Incidence; D007407:Interviews as Topic; D008297:Male; D016485:Needle Sharing; D011159:Population Surveillance; D011446:Prospective Studies; D012307:Risk Factors; D015819:Substance Abuse, Intravenous / Q000453:epidemiology / Q000534:rehabilitation / Q000821:virology*; D014852:Wales / Q000453:epidemiology; D055815:Young Adult