Molecular characterization and epidemic history of hepatitis C virus using core sequences of isolates from Central Province, Saudi Arabia

Distribution pattern, molecular transmission networks, and phylodynamic of hepatitis C virus in China

In China, few molecular epidemiological data on hepatitis C virus (HCV) are available and all previous studies were limited by small sample sizes or specific population characteristics. Here, we report characterization of the epidemic history and transmission dynamics of HCV strains in China. We included HCV sequences of individuals belonging to three HCV surveillance programs: 1) patients diagnosed with HIV infection at the Beijing HIV laboratory network, most of whom were people who inject drugs and former paid blood donors, 2) men who have sex with men, and 3) the general population. We also used publicly available HCV sequences sampled in China in our study. In total, we obtained 1,603 Ns5b and 865 C/E2 sequences from 1,811 individuals. The most common HCV strains were subtypes 1b (29.1%), 3b (25.5%) and 3a (15.1%). In transmission network analysis, factors independently associated with clustering included the region (OR: 0.37, 95% CI: 0.19-0.71), infection subtype (OR: 0.23, 95% CI: 0.1-0.52), and sampling period (OR: 0.43, 95% CI: 0.27-0.68). The history of the major HCV subtypes was complex, which coincided with some important sociomedical events in China. Of note, five of eight HCV subtype (1a, 1b, 2a, 3a, and 3b), which constituted 81.8% HCV strains genotyped in our study, showed a tendency towards decline in the effective population size during the past decade until present, which is a good omen for the goal of eliminating HCV by 2030 in China.

Distribution of hepatitis C virus (HCV) genotypes in a Saudi Arabian hospital during the 2015-2020 period

Hepatitis C virus (HCV) is the leading cause of chronic liver disease. HCV genotypes and subtypes are important predictors of disease progression and antiviral treatment response. To our knowledge, there had been limited studies of HCV genotypes in Qatif, Saudi Arabia. This study aims to assess the distribution of HCV genotypes in Qatif Central Hospital, Qatif, Saudi Arabia. This is a retrospective study of adult patients with HCV infection between January 2015 and December 2020. Only patients with documented HCV genotyping were included. A total of 356 HCVinfected patients fulfilled the inclusion criteria and were included in further analysis. Of those patients, 179 (50.3%) were males, and most were Saudi (N=347, 97.5%). The median age was 60 years, and 191 (53.7%) were 50-69 years of age. Genotype 2 was present in 118 (33.1%) of the patients, followed by genotype 4 in 92 (25.8%), genotype 1B in 62 (17.4%), and genotype 1A in 37 (10.4%). The study showed that HCV genotype 2 is the predominant variant among chronic HCV patients in the study population. Monitoring the epidemiology of HCV genotypes may provide guidance in treatment decisions.

Phylogenetic analysis of the 5' untranslated region of HCV from cirrhotic patients in Khyber Pakhtunkhwa, Pakistan

Hepatitis C virus (HCV), a small, single-stranded RNA virus with a 9.6 kb genome, is one of the most common causes of liver diseases. Sequencing of the 5ʹ untranslated region (UTR) is usually used for HCV genotyping, but it is less important in numerous subtypes due to its scarce sequence variations. This study aimed to identify genotypes using the 5ʹ UTR of HCV from cirrhotic patients of Khyber Pakhtunkhwa (KP). Serum RNA samples (44) were screened by real time PCR to determine the HCV viral load. Nested PCR was performed to identify cDNA and the 5ʹ UTR. The HCV 5′ UTR was sequenced using the Sanger method. MEGA-7 software was used to analyze evolutionary relatedness. After 5ʹ UTR sequencing, 26 samples (59%) were identified as genotype 3, and 2 samples (6%) were identified as genotypes 1, 2 and 4. The most predominant genotype was 3a, and genotype 4 was rarely reported in the phylogenetic tree. Analysis of the HCV 5ʹ UTR is an efficient alternative method for confirmation of various genotypes. Phylogenetic analysis showed that genotype 3 was dominant in the area of KP, Pakistan.

Virological surveillance, molecular phylogeny, and evolutionary dynamics of hepatitis C virus subtypes 1a and 4a isolates in patients from Saudi Arabia

Hepatitis C virus (HCV) subtypes are pre-requisite to predict endemicity, epidemiology, clinical pathogenesis, diagnosis, and treatment of chronic hepatitis C infection. HCV genotypes 4 and 1 are the most prevalent in Saudi Arabia, however; less consensus data exist on circulating HCV subtypes in infected individuals. This study was aimed to demonstrate the virological surveillance, phylogenetic analysis, and evolutionary relationship of HCV genotypes 4 and 1 subtypes in the Saudi population with the rest of the world. Fifty-five clinical specimens from different parts of the country were analyzed based on 5′ untranslated region (5′ UTR) amplification, direct sequencing, and for molecular evolutionary genetic analysis. Pair-wise comparison and multiple sequence alignment were performed to determine the nucleotide conservation, nucleotide variation, and positional mutations within the sequenced isolates. The evolutionary relationship of sequenced HCV isolates with referenced HCV strains from the rest of the world was established by computing pairwise genetic distances and generating phylogenetic trees. Twelve new sequences were submitted to GenBank, NCBI database. The results revealed that HCV subtype 4a is more prevalent preceded by 1a in the Saudi population. Molecular phylogeny predicts the descendants’ relationship of subtype 4a isolates very close to Egyptian prototype HCV strains, while 1a isolates were homogeneous and clustering to the European and North American genetic lineages. The implications of this study highlight the importance of HCV subtyping as an indispensable tool to monitor the distribution of viral strains, to determine the risk factors of infection prevalence, and to investigate clinical differences of treatment outcomes among intergenotypic and intragenotypic isolates in the treated population.

Inhibition of hepatitis C virus genotype 4 replication using siRNA targeted to the viral core region and the CD81 cellular receptor

Hepatitis C virus (HCV) is one of the most important causative agents of hepatitis worldwide. The current study aimed to evaluate the silencing effect of the small interference RNA (siRNA) molecules designed against the core region of HCV genotype 4 (HCV-4) and the CD81 gene, which is the cellular receptor for HCV in the human hepatocytes. RT-PCR was used to measure the changes in both the viral HCV core and the cellular CD81 genes induced by the specific siRNA molecules. Additionally, the fluctuations in either the viral or the cellular proteins of the target regions were tested by flow cytometry and immunofluorescence. The results showed the effectiveness of the used siRNA molecules against the target genes in either RNA or protein levels. The effect of 100 nM of siCD81 and 40 nM of siCore was more evident at 24 and 48 h post-transfection. The combination of the two siRNA molecules resulted in an extra inhibitory effect of the HCV core at both the RNA (85.6%) and protein (98.5%) levels. The current study suggested that targeting of the CD81 cellular receptor and/or the viral HCV core region by the small interference molecules might be a suitable choice in the suppression of HCV-4 replication. This might assist the development of new antiviral medications and provides a new alternative strategy for the targeting and treatment of HCV genotype 4.

Profile of the VERSANT HCV genotype 2.0 assay

INTRODUCTION

Hepatitis C virus (HCV) is divided into 7 genotypes and 67 subtypes. HCV genotype studies reflect the viral transmission patterns as well as human migration routes. In a clinical setting, HCV genotype is a baseline predictor for the sustained virological response (SVR) in chronic hepatitis C patients treated with peginterferon or some direct acting antivirals (DAAs). The Versant HCV genotype 2.0 assay has been globally used for HCV genotyping over a decade. Areas covered: The assay is based on reverse hybridization principle. It is evolved from its former versions, and the accuracy and successful genotyping/subtyping rate are substantially improved. It shows an accuracy of 99-100% for genotypes 1-6. It can also reliably identify subtypes 1a and 1b. However, the assay does not allow a high resolution for many other subtypes. Reasons for indeterminate or inaccurate genotyping/subtyping results are discussed. Expert commentary: Genotyping helps to find the most efficacious and cost-effective treatment regimen. The rapid development of anti-HCV treatment regimens, however, is greatly simplifying laboratory tests. In the near future, the need for HCV genotyping and frequent serial on-treatment HCV RNA tests will decrease along with the wide use of the more potent and pan-genotypic DAA regimens.