title: Frequent HCV reinfection and superinfection in a cohort of injecting drug users in Amsterdam.
abstract: OBJECTIVE
  This study investigates the occurrence of HCV reinfection and superinfection among HCV seroconverters participating in the Amsterdam Cohort Studies among drug users from 1985 through 2005.
  
  
  METHODS
  HCV seroconverters (n=59) were tested for HCV RNA at five different time points: the last visit before seroconversion (t=-1), the first visit after seroconversion (t=1), six months after (t=2) and one year after (t=3) seroconversion, and the last visit prior to November 2005 (t=4). If HCV RNA was present, part of the NS5B region was amplified and sequenced. Additional phylogenetic analysis and cloning was performed to establish HCV reinfection and superinfection.
  
  
  RESULTS
  Multiple HCV infections were detected in 23/59 (39%) seroconverters; 7 had HCV reinfections, 14 were superinfected, and 2 had reinfection followed by superinfection. At the moment of HCV reinfection, 7/9 seroconverters were HIV-negative: persistent HCV reinfection developed in both HIV-positive cases but also in 4/7 HIV-negative cases. In total, we identified 93 different HCV infections, varying from 1 to 4 infections per seroconverter. Multiple HCV infections were observed in 10/24 seroconverters with spontaneous HCV clearance (11 reinfections, 3 superinfections) and in 13/35 seroconverters without viral clearance (20 superinfections).
  
  
  CONCLUSIONS
  HCV reinfection and superinfection are common among actively injecting drug users. This might further complicate the development of an effective HCV vaccine.
authors: Cluster of Infectious Diseases, Public Health Service, Nieuwe Achtergracht 100, 1018 WT Amsterdam, The Netherlands. tvdlaar@ggd.amsterdam.nl
authors: Thijs J W
authors: TJ
authors: van de Laar
authors: Richard
authors: R
authors: Molenkamp
authors: Charlotte
authors: C
authors: van den Berg
authors: Janke
authors: J
authors: Schinkel
authors: Marcel G H M
authors: MG
authors: Beld
authors: Maria
authors: M
authors: Prins
authors: Roel A
authors: RA
authors: Coutinho
authors: Sylvia M
authors: SM
authors: Bruisten
mesh_terms: D000328:Adult; D001483:Base Sequence; D015331:Cohort Studies; D017931:DNA Primers / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D016174:Hepacivirus / Q000145:classification / Q000235:genetics; D006526:Hepatitis C / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D018937:Hepatitis C Antibodies / Q000097:blood; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008969:Molecular Sequence Data; D009426:Netherlands / Q000453:epidemiology; D010802:Phylogeny; D012367:RNA, Viral / Q000097:blood / Q000235:genetics; D012008:Recurrence; D015819:Substance Abuse, Intravenous / Q000150:complications*; D015163:Superinfection / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D017361:Viral Nonstructural Proteins / Q000235:genetics; D055815:Young Adult; D012324:RNA-Dependent RNA Polymerase
chemical_list: D017931:DNA Primers; D018937:Hepatitis C Antibodies; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase