title: A prospective study of hepatitis C incidence in Australian prisoners.
abstract: OBJECTIVE
  To document the relationships between injecting drug use, imprisonment and hepatitis C virus (HCV) infection.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Multiple prisons in New South Wales, Australia.
  
  
  METHODS
  HCV seronegative prisoners with a life-time history of injecting drug use (IDU) were enrolled and followed prospectively (n = 210) by interview and HCV antibody and RNA testing 6-12-monthly for up to 4 years when in prison.
  
  
  METHODS
  HCV incidence was calculated using the person-years method. Cox regression was used to identify predictors of incident infection using time-dependent covariates.
  
  
  RESULTS
  Almost half the cohort reported IDU during follow-up (103 subjects; 49.1%) and 65 (31%) also reported sharing of the injecting apparatus. There were 38 HCV incident cases in 269.94 person-years (py) of follow-up with an estimated incidence of 14.08 per 100 py [confidence interval (CI) = 9.96-19.32]. Incident infection was associated independently with Indigenous background, injecting daily or more and injecting heroin. Three subjects were RNA-positive and antibody-negative at the incident time-point, indicating early infection, which provided a second incidence estimate of 9.4%. Analysis of continuously incarcerated subjects (n = 114) followed over 126.73 py, identified 13 new HCV infections (10.26 per 100 py, CI = 5.46-17.54), one of which was an early infection case. Bleach-cleansing of injecting equipment and opioid substitution treatment were not associated with a significant reduction in incidence.
  
  
  CONCLUSIONS
  In New South Wales, Australia, imprisonment is associated with high rates of hepatitis C virus transmission. More effective harm reduction interventions are needed to control HCV in prison settings.
authors.affiliation: Inflammation and Infection Research Centre, School of Medical Sciences, The University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Fabio
authors.initials: F
authors.lastname: Luciani
authors.forename: Neil Arvin
authors.initials: NA
authors.lastname: Bretaña
authors.forename: Suzy
authors.initials: S
authors.lastname: Teutsch
authors.forename: Janaki
authors.initials: J
authors.lastname: Amin
authors.forename: Libby
authors.initials: L
authors.lastname: Topp
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Dore
authors.forename: Lisa
authors.initials: L
authors.lastname: Maher
authors.forename: Kate
authors.initials: K
authors.lastname: Dolan
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Lloyd
mesh_terms: D000328:Adult; D005260:Female; D006526:Hepatitis C / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D009517:New South Wales / Q000453:epidemiology; D011329:Prisoners / Q000706:statistics & numerical data*; D011446:Prospective Studies; D012307:Risk Factors; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*; D055815:Young Adult
keywords: Hepatitis C virus; incarceration; incidence; injecting drug use; risk behaviour