MOLECULAR EPIDEMIOLOGY OF NON-1B HCV STRAINS INFECTING ROMANIAN PATIENTS.

Introduction: Through its severe complications, hepatitis C virus (HCV) infection is an important cause of liver disease worldwide. The numerous HCV genotypes and subtypes are widely spread, associated with different regions or populations/social groups, and display distinct response to antivirals. Some genotypes/subtypes are prone to mutation, making them less susceptible even to the direct-acting antivirals. HCV prevalence in Romania is considered the highest in Europe, predominating subtype 1b. Circulation of other HCV subtypes in Romania is documented. Objectives: We conducted a study to characterize non-1b HCV isolates circulating in Romania between 2013 and 2014 in naïve patients. Methods: Blood samples were used for HCV genotyping, phylogenetic analysis, detection of antiviral resistance mutations, and IL28B genotyping. Results: Subtypes 1a, 3a and 4a were detected by sequencing a fragment of core region. Phylogenetic analysis showed high resemblance between the non-1b strains identified in this study and older Romanian strains. As well as the previous non-1b Romanian strains, most of the isolates in our study originated from intravenous drug users. The low genetic diversity of non-1b isolates circulating in Romania, corroborated with the epidemiological data, suggested that the number of introduction events of non-1b isolates in our country was limited and that they have been endemically circulating in a specific group. Subtype 1a strains were assigned to clade II, known to gather isolates not harboring NS3 Q80K polymorphism responsible for simeprevir resistance. Conclusion: The transmission of non-1b HCV strains identified in this study could be related to the administration of intravenous drugs. [ABSTRACT FROM AUTHOR]