High incidence of the hepatitis C virus recombinant 2k/1b in Georgia: Recommendations for testing and treatment

Aim The first hepatitis C virus (HCV) recombinant, RF2k/1b, was initially described from Russia and has since then been identified from patients in Ireland, Estonia, Uzbekistan and Cyprus. Many of these patients originated from Georgia; however, there is no information on its prevalence in Georgia or its susceptibility to antiviral treatment. Methods We retrospectively sequenced the non-structural region 5B (NS5B) of the HCV genome in samples from 72 Georgian patients, 36 of whom had been treated with pegylated interferon and ribavirin. Results The HCV genotype was determined using the Versant HCV Genotype v2 kit. Based on this typing, 32 patients (44.4%) were infected with genotype 1, 21 (29.1%) genotype 2 and 19 (26.3%) genotype 3. Partial NS5B of these strains was sequenced and analyzed for type, with concordant genotype results for all type 1 and 3 strains. Discrepant results were observed for genotyped 2 strains, with 16 (76%) having NS5B of subtype 1b. On phylogenetic analysis, 15 NS5B sequences of these strains were found in a clade formed by recombinant RF2k/1b strains. The remaining discordant sequence was found within a clade formed by 1b strains. Conclusion Our findings show that the RF2k/1b recombinant strain is common among Georgian patients previously assumed to be infected with genotype 2. Because genotyping is mainly performed to decide treatment strategies, there is a need to determine the genotype by analysis of at least two genomic regions in strains from Georgian patients considered infected with genotype 2 based on standard HCV genotyping methods.