RESUMEN
There is a lack of updated nationwide records regarding hepatitis C virus (HCV) infection among drug addicts in Italy. The prevalence and characteristics of HCV infection in a national sample of drug addicts in Italy were determined. Five hundred forty-three drug addicts (mean age 35.3 years, 85.1% males), selected from 25 Italian Centers for Substance Dependence were enrolled to be evaluated for anti-HCV, HCV-RNA, HCV genotype, HBV markers, anti-HDV, and anti-HIV during the period of April-November 2009. Anti-HCV prevalence was 63.9%. HCV-RNA was detected in 68.3% of patients positive for anti-HCV. Genotypes 1 and 3 prevailed (49.3% and 39.7%, respectively). However, 9.3% of the subjects had genotype 4, a rate over threefold higher than the one observed in 1996 among drug addicts in central Italy. Needle sharing was the strongest independent predictor of the likelihood to contract an HCV infection (OR 8.9; 95% CI: 5.0-16.0). Only 19.3% of subjects received antiviral treatment for HCV. The prevalence of HBsAg and HIV positivity was 2.8% and 3.1%, respectively. The pattern of HBV markers showed that nearly one-third of subjects had been vaccinated, while 42.3% were negative for any marker of HCV. The prevalence of HCV infection is high among drug addicts in Italy. The incidence of Genotype 4 is increasing and this may lead to the spreading of the disease to the general population in the near future. Efforts should be made to improve the rate of antiviral treatment for drug addicts with HCV infection and vaccination against hepatitis B.