Prevalence and incidence of hepatitis C in injecting drug users attending genitourinary medicine clinics

(Accepted 7 November 2008; first published online 23 December 2008)SUMMARYSurveillance reports and prevalence studies have indicated that injecting drug users (IDUs)contribute more to the hepatitis C epidemic in the United Kingdom than any other risk group.Information on both the prevalence and incidence of hepatitis C in IDUs is therefore essential tounderstanding the epidemiology of this infection. The prevalence of hepatitis C in specimens fromthe Unlinked Anonymous Prevalence Monitoring Programme collected in 1995, 1996, 1998, 1999,2000, and 2001 was determined using residual syphilis serology specimens from IDUs attending15 genitourinary medicine (GUM) clinics in and outside London. These specimens were tested forantibodies to hepatitis C virus (anti-HCV). Using this cross-sectional design, anti-HCV-negativespecimens were tested for HCV RNA to identify incident infections during the ‘window’ period ofinfection, and thus to estimate HCV incidence. Results of the multivariable analysis showed thatthere was marked variation in prevalence by clinic (P