Hepatitis C virus (HCV) genotype 1b displays higher genetic variability of hypervariable region 1 (HVR1) than genotype 3

The Transmission Route and Selection Pressure in HCV Subtype 3a and 3b Chinese Infections: Evolutionary Kinetics and Selective Force Analysis

Hepatitis C virus (HCV) genotype 3 (GT-3) represents 22–30% of all infections and is the second most common genotype among all HCV genotypes. It has two main subtypes, GT-3a and GT-3b, that present epidemiological differences in transmission groups. This report generated 56 GT-3a and 64 GT-3b whole-genome sequences to conduct an evolutionary kinetics and selective force analysis with reference sequences from various countries. Evolutionary analysis showed that HCV GT-3a worldwide might have been transmitted from the Indian subcontinent to South Asia, Europe, North America and then become endemic in China. In China, GT-3a may have been transmitted by intravenous drug users (IDUs) and become endemic in the general population, while GT-3b may have originated from IDUs and then underwent mutual transmission between blood donors (BDs) and IDUs, ultimately becoming independently endemic in IDUs. Furthermore, the spread of GT-3a and GT-3b sequences from BD and IDU populations exhibit different selective pressures: the proportion of positively selected sites (PPSs) in E1 and E2 from IDUs was higher than in BDs. The number of positive selection sites was higher in GT-3b and IDUs. These results indicate that different selective constraints act along with the GT-3a and GT-3b genomes from IDUs and BDs. In addition, GT-3a and GT-3b have different transmission routes in China, which allows us to formulate specific HCV prevention and control strategies in China.

Similarities, differences, and possible interactions between hepatitis E and hepatitis C viruses: Relevance for research and clinical practice

Hepatitis E virus (HEV) and hepatitis C virus (HCV) are both RNA viruses with a tropism for liver parenchyma but are also capable of extrahepatic manifestations. Hepatitis E is usually a viral acute fecal-oral transmitted and self-limiting disease presenting with malaise, jaundice, nausea and vomiting. Rarely, HEV causes a chronic infection in immunocompromised persons and severe fulminant hepatitis in pregnant women. Parenteral HCV infection is typically asymptomatic for decades until chronic complications, such as cirrhosis and cancer, occur. Despite being two very different viruses in terms of phylogenetic and clinical presentations, HEV and HCV show many similarities regarding possible transmission through organ transplantation and blood transfusion, pathogenesis (production of antinuclear antibodies and cryoglobulins) and response to treatment with some direct-acting antiviral drugs. Although both HEV and HCV are well studied individually, there is a lack of knowledge about coinfection and its consequences. The aim of this review is to analyze current literature by evaluating original articles and case reports and to hypothesize some interactions that can be useful for research and clinical practice.

Distribution of hepatitis C virus genotypes in Punjab region, Pakistan, based on a study of 4177 specimens

Hepatitis C virus (HCV) is a heterogenetic infectious agent that affects a huge proportion of population around the globe. Diverse distribution of multiple subtypes of HCV makes it mandatory and remarkably imperative to understand the genotypic distribution in target population. It could serve as an indictive guideline for the improvement of diagnostic methodologies, and development of effective therapies against this viral infection, in order to improve the infected patients' quality of life. This study included HCV infected patients presented to the diagnostic facility of the Centre for Applied Molecular Biology, University of Punjab, Lahore, between 2016 and 2019. During the 4 years of study, samples were collected from 4177 subjects. Our data revealed no significant differences regarding the prevalence of various genotypes between genders in the adult population. Genotyping was carried out by following the Ohno protocol. The obtained results shown that genotype 3a is the most frequent genotype and accounts for 66.29% of cases. Among other genotypes, 1a is 2.11%, 1b is 0.07%, 3b is 1.89%, 5a is 0.02%, while genome of 28.23% patients was untypable; 1.22% of the samples were non-detectable as viremic. An important concern is that this untypable genome in HCV infected patients may indicate possible mutation of HCV.