Background:In industrialised countries, injecting drug use is currently the most important risk factor for infection with hepatitis C, resulting in high prevalence of hepatitis C among injecting drug users (IDUs) in Slovakia in the range od 25 – 40 %. Aims: The first aim of the present work was in the risk group of IDUs determine the seroprevalence of HCV evolution in years 2004 – 2009. The second objective was to evaluate the success of the treatment of chronic hepatitis C (CHHC) by combined immunomodulatory therapy with pegylated interferon-alfa (PEG-IFN-α) + ribavirin (R). Methods:A total number of 962 probands (682 males and 280 females) with mean age 27 years were investigated in the years 2004 – 2009. Standard virological tests were performed. We evaluated the success of treatment in 302 previously untreated abstinent IDUs (AIDUs) (83 F, 219 M) with CHHC with a mean age of 28 years (17 – 50 years) who have completed treatment. Administered PEG-IFN-α and R in the standard dosing regimen and duration of treatment varies according to genotype – patients with genotype 3 were treated with 24 and 48 weeks with genotype 1. The criterion for the assessment of sustained virological response (SVR) were HCV RNA negative at 24 weeks after stopping treatment. Results:In the epidemiological study the prevalence of anti-HCV positivity ranged between 34 % – 78 %, and HCV RNA in the range of 17 % – 71 %. Distribution of genotypes during the period offset the slight predominance of genotype 3. In the treatment group after 12 week and at the end of treatment response HCV RNA negative findings 270 (89 %) and 290 (96 %) of patients, respectively. The overall SVR was reported in 285 (94 %) of patients, with genotype 3 patients responded in 98 % (186 patients), 95 (88 %) with genotype 1 and 4 (100 %) patients with combination of genotypes 1 and 3. Conclusion:The results of epidemiological studies confirm persistence of high positive anti-HCV and HCV RNA in the risk group of IDUs. Factors involved in achieving high efficiency of treatment were: early detection of infection in young population of AIDUs through the search program; prevalence of genotype 3, and a low degree of fibrosis. Optimal adherence to therapy also significantly contributed to the high efficiency of treatment.

Key words: intravenous drug users – hepatitis C – pegylated interferon-alfa – ribavirin