Hepatitis C virus molecular epidemiology in Uzbekistan.

The aim of this study was to identify hepatitis C virus (HCV) genotypes and to estimate their prevalence in various risk groups and the regional distribution in Uzbekistan. Preliminary serological screening of 1,269 subjects revealed 6.5% anti-HCV-positive in a general population, 27.1% in patient groups, and 51.7% among intravenous drug users. HCV genotypes of 104 anti-HCV-positive subjects were determined using a PCR-genotyping system in core region, and the results were supported by nucleotide sequencing of the NS5B region. Genotype 1b identified in total 64.2%, was the most prevalent. The genotype 3a identified in 25.0% was the second one distributed. HCV genotypes 2a, 1a, 2b, and 3b were identified in 3.8%, 2.9%, 2.9%, and 1.0% of cases, respectively. The intravenous drug users were distinguished from other groups by having the highest prevalence of genotype 3a, i.e., 50.0%, higher than the 33.3% for genotype 1b in this group. Geographically, genotype 1b was common; genotype 3a was also found frequently in all three regions. Uncommon HCV genotypes (1a, 2a, 2b, and 3b) were found in comparatively greater variability in the western region. Molecular evolutionary analysis based on the NS5B region did not reveal specific clustering or indigenous strains among Uzbekistan HCV isolates. In summary, two main mechanisms of HCV infection distribution were observed in Uzbekistan: HCV 1b genotype infection is widespread through blood products, and HCV 3a genotype infection is spreading through the growing number of intravenous drug users. Copyright 2003 Wiley-Liss, Inc.