Background: Genotype distribution of hepatitis C virus (HCV) is relatively uniform in Prague, Czech Republic. Unlike the other developed countries where HCV genotype 3 is increasingly associated with injection drug users (IDU), subtype 1b remains the most prevalent HCV subtype in Prague, regardless of risk factors.
Objective: We wished to determine if subtype 1b strains could be further differentiated by comparing the conserved 5'NC sequences of the strains infecting IDU and non-IDU populations.
Study design: All prospectively collected serum samples that were HCV RNA positive were genotyped according to the 5'NC and NS5b regions. All 5'NC sequences were further analyzed for new mutations and these data were compared to patient epidemiologic information.
Results: We found eight 5'NC sequence variants among 96 specimens tested. Further analysis of subtype 1b strains showed that a variant with a nucleotide insertion at -138 positions was found only among non-IDU subjects, while the variant with T-->C substitution at -94 was found only among the IDUs.
Conclusions: These observations suggest that the current HCV transmission between the IDU and non-IDU populations is uncommon, and may reflect the beginning of divergence of HCV genotypes in the IDU population in Prague.