Identification of 19 novel hepatitis C virus subtypes—further expanding HCV classification

  • Background: Hepatitis C virus (HCV) is currently classified into 8 genotypes and 86 subtypes. The objective of this study was to characterize novel HCV subtypes and to investigate the impact of subtypes on treatment outcome. Methods: Full-genome sequencing was performed on HCV plasma samples with <85% sequence homology of NS3, NS5A, and/or NS5B to HCV genotype (GT) 1–8 reference strains. Results: A total of 14 653 patients with GT1–6 HCV infection were enrolled in clinical studies of sofosbuvir-based regimens. For the majority of the patients, a specific subtype could be assigned based on a close genetic relationship to previously described subtypes. However, for 19 patients, novel subtypes were identified with <85% homology compared with previously described subtypes. These novel subtypes had the following genotypes: 9 in GT2, 5 in GT4, 2 in GT6, and 1 each in GT1, GT3, and GT5. Despite the presence of polymorphisms at resistance-associated substitution positions, 18 of the 19 patients treated with sofosbuvir-containing therapy achieved SVR12. Conclusions: Nineteen novel HCV subtypes were identified, suggesting an even greater genetic diversity of HCV subtypes than previously recognized.

Download full text files

Export metadata

Author:Charlotte Hedskog, Bandita Parhy, Silvia Chang, Stefan ZeuzemORCiDGND, Christophe Moreno, Stephen D. Shafran, Sergio M. Borgia, Tarik Asselah, Laurent Alric, Armand Abergel, Jyh-Jou Chen, Jane Collier, Dharmesh Kapoor, Robert Hyland, Peter Simmonds, Hongmei Mo, Evguenia S. Svarovskaia
Pubmed Id:
Parent Title (English):Open Forum Infectious Diseases
Publisher:Oxford University Press
Place of publication:Oxford
Document Type:Article
Year of Completion:2019
Date of first Publication:2019/02/22
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2019/04/18
Tag:direct-acting antivirals (DAAs); phylogenetic analysis; resistance-associated substitutions (RAS); sofosbuvir; velpatasvir; voxilaprevir
Issue:3, ofz076
Page Number:9
First Page:1
Last Page:9
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (, which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work is properly cited. For commercial re-use, please contact
Institutes:Medizin / Medizin
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Licence (German):License LogoCreative Commons - Namensnennung-Nicht kommerziell - Keine Bearbeitung 4.0