Phylogenetic Analysis of NS5B Region of Hepatitis C Genotype 3a Virus among Different Risk Groups in Iran

Hepatitis C virus (HCV) is a major cause of liver diseases. Transmission of HCV, as a blood-borne virus, is a major concern for the safety of blood products. In Iran, intravenous drug abuse is a major risk factor for HCV transmission. Recently a change in the distribution of HCV genotype among Iranian blood donors has been reported, and genotype 3a is reported as the most frequent genotype. Also, genotype 3a is the dominant genotype among IDUs.

To investigate the association between HCV genotype 3a circulating in the community, sequences of HCV genotype 3a were analyzed among different risk groups in Iran.

In this cross-sectional study, a partial sequence of the NS5B region of the HCV genome was isolated from 58 blood donors, 48 intravenous drug users (IDUs), and 31 patients with inherited bleeding disorders (IBDs) infected with HCV genotype 3a were included. The published sequence data were obtained from the Gen Bank database and were compared to construct the phylogenetic trees.

Of 58 blood donors infected with subtype 3a, 31 (53.5%) reported the risk of intravenous drug abuse. In the phylogenetic tree, no separate cluster was formed to differentiate between HCV sequences in blood donors and IDUs. A cluster at the middle level was found in the phylogenetic tree formed by sequences from blood donors, IDUs, and patients with inherited bleeding disorders.

The phylogenetic tree showed the phylogenetic mixing of genotype 3a sequences in BDs, IBD patients, and IDUs. The results confirmed the extensive transmission of IDU-related genotype 3a towards the general population.