High prevalence of hepatitis C virus infection in Belgian intravenous drugusers and potential role of the "Cotton-filter" in transmission: the GEMT study

Aims: To estimate viral seroprevalences for HCV, HBV and HIV among belgian intravenous (IVDU) and non intravenous (non-IVDU) drug users; to assess ris k factors for HCV infection in IVDU; to assess feasability of chronic hepat itis C follow-up in this population. Design : Cross-sectional study. Demographic and behavioural characteristics were obtained by a standardized questionnaire. Serum samples were tested f or ACV, HBV and HIV. Subjects and setting : 329 patients (244 IVDU and 85 non-IVDU) attending te n general practitioners in 1995. Results: HCV seroprevalence was 78.3%; it was 35.7% for HBV and 0.9% for HI V in IVDU, vs 2.4%, 8.3% and OB, respectively, in non-IVDU. In logistic reg ression analysis, independent risk factors for HCV infection were : 1/ shar ing of syringes and/or of "cottons" used as filters (adjusted prevalence od ds ratio [POR] = 31.7: 95% confidence interval [CI] = 9.8 - 102.5), 2/ dura tion of injecting upper than one month (adjusted FOR = 8.6; CI = 3.0-23.7) and 3/ age (adjusted FOR = 1.2 by year of difference; CI = 1.0-1.3). A bioc hemical follow-up was obtained in 70% of HCV seropositive users; 79.5% of t hem had chronic hepatitis C (mean value of ALT = 3.5 times upper normal val ue, range 1.1-23.0), Among these, 24.7% went through liver biopsy during th e three years follow-up period of the study. Conclusions: HCV seroprevalence is very high among belgian IVDU. Prevention strategics have to focuse on neophytes injectors. They must be urgently re visited for what concern needles/syringes exchange programs: "cottons'' mus t be included. Follow-up and treatment of chronic hepatitis C seem to be po orly effective among drug users.