title: The hepatitis C epidemic among HIV-positive MSM: incidence estimates from 1990 to 2007.
abstract: BACKGROUND
  Outbreaks of acute hepatitis C virus (HCV) infection among HIV-infected MSM have been described since 2000. However, phylogenetic analysis suggests that the spread of HCV started around 1996. We estimated the incidence of HCV in HIV-infected MSM with well estimated dates of HIV seroconversion from 1990 to 2007.
  
  
  METHODS
  Data from 12 cohorts within the Concerted Action on SeroConversion to AIDS and Death in Europe (CASCADE) Collaboration were used. HCV incidence was estimated using standard incidence methods and methods for interval-censored data. We accounted for the fact that routine HCV data collection in each cohort started in different calendar years.
  
  
  RESULTS
  Of 4724 MSM, 3014 had an HCV test result and were included. Of these, 124 (4%) had only positive HCV test results, 2798 (93%) had only negative results and 92 (3%) had both. In 1990, HCV incidence ranged from 0.9 to 2.2 per 1000 person-years, depending on the analysis strategy used. HCV incidence increased up to 1995 when it was estimated to range between 5.5 and 8.1 per 1000 person-years. From 2002 onwards, it increased substantially to values between 16.8 and 30.0 per 1000 person-years in 2005 and between 23.4 and 51.1 per 1000 person-years in 2007.
  
  
  CONCLUSIONS
  Our data support phylodynamic findings that HCV incidence had already increased among HIV-infected MSM from the mid-1990s. However, the main expansion of the HCV epidemic started after 2002. Incidence estimates obtained from cohort studies may help identify changes in the spread of important infections earlier and should guide routine testing policies to minimize further disease burden.
authors.affiliation: Cluster of Infectious Diseases, Public Health Service Amsterdam, Amsterdam, The Netherlands. jvdhelm@ggd.amsterdam.nl
authors.forename: Jannie J
authors.initials: JJ
authors.lastname: van der Helm
authors.forename: Maria
authors.initials: M
authors.lastname: Prins
authors.forename: Julia
authors.initials: J
authors.lastname: del Amo
authors.forename: Heiner C
authors.initials: HC
authors.lastname: Bucher
authors.forename: Geneviève
authors.initials: G
authors.lastname: Chêne
authors.forename: Maria
authors.initials: M
authors.lastname: Dorrucci
authors.forename: John
authors.initials: J
authors.lastname: Gill
authors.forename: Osamah
authors.initials: O
authors.lastname: Hamouda
authors.forename: Mette
authors.initials: M
authors.lastname: Sannes
authors.forename: Kholoud
authors.initials: K
authors.lastname: Porter
authors.forename: Ronald B
authors.initials: RB
authors.lastname: Geskus
mesh_terms: D000328:Adult; D058872:Epidemics; D005060:Europe / Q000453:epidemiology; D006679:HIV Seropositivity / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D016174:Hepacivirus / Q000145:classification / Q000302:isolation & purification*; D006526:Hepatitis C / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D018451:Homosexuality, Male / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D010802:Phylogeny; D012725:Sexual Behavior