# Genetic Diversity of the Hepatitis C Virus Among Patients with HIV in EECA Countries

## TL;DR

This study examines the genetic diversity of Hepatitis C Virus (HCV) among people with HIV in three EECA countries, revealing dominant subtypes and shared transmission routes.

## Contribution

The study reports the first detection of HCV subtype 4a in Armenia and identifies transmission clusters among people who inject drugs.

## Key findings

- HCV subtype 3a was the most common in Armenia and Kyrgyzstan.
- HCV subtype 4a was detected for the first time in Armenia.
- Phylogenetic analysis showed shared transmission routes among people who inject drugs.

## Abstract

Against the backdrop of active efforts to combat HCV worldwide with the help of DAAs, knowledge of the genetic diversity of HCV in the general population and in groups most at risk of infection is becoming increasingly important. The aim of this study was to characterize the molecular genetic diversity of HCV among individuals with HIV in Armenia, Kyrgyzstan and the Krasnoyarsk Krai region of Russia. The study included residents of Armenia (n = 73), Kyrgyzstan (n = 180) and the Krasnoyarsk Territory (n = 141) with HIV/HCV co-infection who were under observation at AIDS centers in these countries, collected between 2021 and 2023. The Core/E1 gene fragments obtained were analyzed using the maximum likelihood method to create a phylogenetic tree. HCV subtype 3a was dominant in Armenia (56.2%) and Kyrgyzstan (51.4%). The circulation of HCV subtype 4a was detected for the first time in Armenia, while the spread of HCV genotype 2, represented by three different subtypes, was documented in Kyrgyzstan. The genetic diversity of HCV in Krasnoyarsk Krai is consistent with the findings of previous Russian studies. Phylogenetic analysis revealed the formation of HCV clusters with a high level of bootstrap support, suggesting shared transmission routes, predominantly among PWID. This suggests that there are common routes of HCV transmission between and within countries.