title: Estimating the number of injecting drug users in Scotland's HCV-diagnosed population using capture-recapture methods.
abstract: In countries maintaining national hepatitis C virus (HCV) surveillance systems, a substantial proportion of individuals report no risk factors for infection. Our goal was to estimate the proportion of diagnosed HCV antibody-positive persons in Scotland (1991-2010) who probably acquired infection through injecting drug use (IDU), by combining data on IDU risk from four linked data sources using log-linear capture-recapture methods. Of 25,521 HCV-diagnosed individuals, 14,836 (58%) reported IDU risk with their HCV diagnosis. Log-linear modelling estimated a further 2484 HCV-diagnosed individuals with IDU risk, giving an estimated prevalence of 83. Stratified analyses indicated variation across birth cohort, with estimated prevalence as low as 49% in persons born before 1960 and greater than 90% for those born since 1960. These findings provide public-health professionals with a more complete profile of Scotland's HCV-infected population in terms of transmission route, which is essential for targeting educational, prevention and treatment interventions.
authors.affiliation: Health Protection Scotland, Glasgow, Scotland, UK.
authors.forename: S A
authors.initials: SA
authors.lastname: McDonald
authors.forename: S J
authors.initials: SJ
authors.lastname: Hutchinson
authors.forename: C
authors.initials: C
authors.lastname: Schnier
authors.forename: A
authors.initials: A
authors.lastname: McLeod
authors.forename: D J
authors.initials: DJ
authors.lastname: Goldberg
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006526:Hepatitis C / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012107:Research Design; D012606:Scotland / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000453:epidemiology* / Q000821:virology