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©2007 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Jan 7, 2007; 13(1): 14-21
Published online Jan 7, 2007. doi: 10.3748/wjg.v13.i1.14
Published online Jan 7, 2007. doi: 10.3748/wjg.v13.i1.14
Hepatitis B virus taxonomy and hepatitis B virus genotypes
Stephan Schaefer, Abteilung für Virologie, Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universität Rostock, Schillingallee 70, D-18057 Rostock, Germany
Author contributions: All authors contributed equally to the work.
Correspondence to: Stephan Schaefer, Abteilung für Virologie, Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universität Rostock Schillingallee 70, D-18057 Rostock, Germany. stephan.schaefer@med.uni-rostock.de
Telephone: +49-381-4945920 Fax: +49-381-4945925
Received: September 1, 2006
Revised: September 14, 2006
Accepted: October 12, 2006
Published online: January 7, 2007
Revised: September 14, 2006
Accepted: October 12, 2006
Published online: January 7, 2007
Abstract
Hepatitis B virus (HBV) is a member of the hepadnavirus family. Hepadnaviruses can be found in both mammals (orthohepadnaviruses) and birds (avihepadnaviruses). The genetic variability of HBV is very high. There are eight genotypes of HBV and three clades of HBV isolates from apes that appear to be additional genotypes of HBV. Most genotypes are now divided into subgenotypes with distinct virological and epidemiological properties. In addition, recombination among HBV genotypes increases the variability of HBV. This review summarises current knowledge of the epidemiology of genetic variability in hepadnaviruses and, due to rapid progress in the field, updates several recent reviews on HBV genotypes and subgenotypes.
Keywords: Orthohepadnavirus; Avihepadnavirus; Hepatitis B virus; Genotype, Subgenotype; Recombi-nation