High prevalence of genotype 4 among hepatitis C virus-infected intravenous drug users in north-eastern Poland.

The aim of this study was to describe the distribution of hepatitis C genotypes among intravenous drug users in north-eastern Poland. The study group included intravenous drug users recruited at a drug treatment center and a clinic for HIV-infected patients. HCV infection was confirmed by qualitative nested RT-PCR to test for the presence of HCV RNA. Genotypes were determined by 5'UTR sequencing and comparing the results with known genotype sequences. Among 111 HCV-infected and HCV-RNA-positive intravenous drug users, the most prevalent genotypes were 1 (38.7%), 3 (37.8%), and 4 (23.4%). Most infections with genotype 4 (88.5%) were found among HCV-HIV-coinfected drug users. The study demonstrated a high prevalence of genotype 4 (23.4%) among HCV-infected Polish drug users.