Chronic hepatitis C virus (HCV) infection and its progression are major health problems that many countries including Saudi Arabia are facing. Determination of HCV genotypes and subgenotypes is critical for epidemiological and clinical analysis and aids in the determination of the ideal treatment strategy that needs to be followed and the expected therapy response. Although HCV infection has been identified as the second most predominant type of hepatitis in Saudi Arabia, little is known about the molecular epidemiology and genetic variability of HCV circulating in the Jeddah province of Saudi Arabia. The aim of this study was to determine the dominance of various HCV genotypes and subgenotypes circulating in Jeddah using partial sequencing of the NS5B region. To the best of our knowledge, this is the first study of its kind in Saudi Arabia. To characterize HCV genotypes and subgenotypes, serum samples from 56 patients with chronic HCV infection were collected and subjected to partial NS5B gene amplification and sequence analysis. Phylogenetic analysis of the NS5B partial sequences revealed that HCV/1 was the predominant genotype (73%), followed by HCV/4 (24.49%) and HCV/3 (2.04%). Moreover, pairwise analysis also confirmed these results based on the average specific nucleotide distance identity: ±0.112, ±0.112, and ±0.179 for HCV/1, HCV/4, and HCV/3, respectively, without any interference between genotypes. Notably, the phylogenetic tree of the HCV/1 subgenotypes revealed that all the isolates (100%) from the present study belonged to the HCV/1a subgenotype. Our findings also revealed similarities in the nucleotide sequences between HCV circulating in Saudi Arabia and those circulating in countries such as Morocco, Egypt, Canada, India, Pakistan, and France. These results indicated that determination of HCV genotypes and subgenotypes based on partial sequence analysis of the NS5B region is accurate and reliable for HCV subtype determination.
El Hadad, S., Al-Hamdan, H., & Linjawi, S. (2017). Partial sequencing analysis of the NS5B region confirmed the predominance of hepatitis C virus genotype 1 infection in Jeddah, Saudi Arabia. PLoS ONE, 12(5). https://doi.org/10.1371/journal.pone.0178225