title: A prospective study to examine persistent HCV reinfection in injection drug users who have previously cleared the virus.
abstract: BACKGROUND
  Many HCV-infected persons with recent or ongoing injection drug use (IDU) do not receive HCV treatment due to the perceived risk of HCV reinfection. There are few prospective studies investigating HCV reinfection among IDUs.
  
  
  METHODS
  Two hundred and twenty-four persons with past or ongoing IDU were followed from 1997 to 2007. Baseline and every 6-month follow-up data were collected including demographics, IDU, and sexual behaviors. Serum was tested for the presence of HCV antibody and serially for HCV RNA. Resolvers were defined as HCV antibody and RIBA positive and RNA negative at two consecutive time points or as becoming HCV RNA negative after HCV antiviral treatment. Reinfection was defined by the presence of HCV RNA at > or =2 visits.
  
  
  RESULTS
  One hundred and eighty-six persons had chronic HCV and 38 had resolved HCV. The resolvers were followed for a total of 214 person-years. Forty-two percent of resolvers reported ongoing IDU, representing 58 person-years of IDU. Only one reinfection occurred in the resolvers, for a reinfection rate of 0.47 cases/100 person-years of follow-up. The single reinfection, which occurred in a person who continued to inject drugs, represents a reinfection rate of 1.75 cases/100 person-years of IDU.
  
  
  CONCLUSIONS
  These data suggest that despite ongoing IDU, persistent HCV reinfection is lower than previously published. This can be attributed to a more clinically relevant definition of reinfection. This information will better help clinicians make informed decisions regarding HCV treatment options for patients who may continue to inject illicit drugs.
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, CA 94121, USA. sue.currie@va.gov
authors.forename: Sue L
authors.initials: SL
authors.lastname: Currie
authors.forename: James C
authors.initials: JC
authors.lastname: Ryan
authors.forename: Daniel
authors.initials: D
authors.lastname: Tracy
authors.forename: Teresa L
authors.initials: TL
authors.lastname: Wright
authors.forename: Sally
authors.initials: S
authors.lastname: George
authors.forename: Rosemary
authors.initials: R
authors.lastname: McQuaid
authors.forename: Michael
authors.initials: M
authors.lastname: Kim
authors.forename: Hui
authors.initials: H
authors.lastname: Shen
authors.forename: Alexander
authors.initials: A
authors.lastname: Monto
mesh_terms: D000437:Alcoholism / Q000453:epidemiology; D003710:Demography; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification; D006526:Hepatitis C / Q000453:epidemiology* / Q000276:immunology / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012367:RNA, Viral / Q000235:genetics; D012008:Recurrence; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*; D011795:Surveys and Questionnaires
chemical_list: D012367:RNA, Viral