Expanded classification of hepatitis C virus into 7 genotypes and 67 subtypes: Updated criteria and genotype assignment web resource

Abstract

The 2005 consensus proposal for the classification of hepatitis C virus (HCV) presented an agreed and uniform nomenclature for HCV variants and the criteria for their assignment into genotypes and subtypes. Since its publication, the available dataset of HCV sequences has vastly expanded through advancement in nucleotide sequencing technologies and an increasing focus on the role of HCV genetic variation in disease and treatment outcomes. The current study represents a major update to the previous consensus HCV classification, incorporating additional sequence information derived from over 1,300 (near-)complete genome sequences of HCV available on public databases in May 2013. Analysis resolved several nomenclature conflicts between genotype designations and using consensus criteria created a classification of HCV into seven confirmed genotypes and 67 subtypes. There are 21 additional complete coding region sequences of unassigned subtype. The study additionally describes the development of a Web resource hosted by the International Committee for Taxonomy of Viruses (ICTV) that maintains and regularly updates tables of reference isolates, accession numbers, and annotated alignments (http://talk.ictvonline.org/links/hcv/hcv-classification.htm). The Flaviviridae Study Group urges those who need to check or propose new genotypes or subtypes of HCV to contact the Study Group in advance of publication to avoid nomenclature conflicts appearing in the literature. While the criteria for assigning genotypes and subtypes remain unchanged from previous consensus proposals, changes are proposed in the assignment of provisional subtypes, subtype numbering beyond “w,” and the nomenclature of intergenotypic recombinant. Conclusion: This study represents an important reference point for the consensus classification of HCV variants that will be of value to researchers working in clinical and basic science fields. (Hepatology 2014;59:318-327)

HCV genotype 3: a wolf in sheep’s clothing

“…Genotype 3 (HCV G3) is one of the seven recognized genotypes. [2] HCV G3 is the second most common genotype overall and is estimated to account for 54.3 million cases throughout the world (30.1%). [1] Although three-quarters of them occur in South Asia where it is endemic, the 3a subtype is an 'epidemic subtype' widely distributed geographically, probably associated with injecting drug use.…”

Interleukin-28B Polymorphism is a Pharmacogenetic Predictor during Sofosbuvir Plus Pegylated Interferon and Ribavirin Therapy for Chronic Hepatitis C Egyptian Patients

“…Seven HCV genotypes and sixty seven subtypes have been identified [12]. HCV genotype 4 (HCV-G4) is the most common infection in Egypt, approximately 90% of all HCV patients [13][14][15].…”

Historical Trends in the Hepatitis C Virus Epidemics in North America and Australia

“…The hepatitis C virus (HCV) genera are divided into 7 genotypes and 67 subtypes [6]. The subtypes that have a global presence are 1a, 1b, 2a, 2b, and 3a [7].…”