HBV subgenotype misclassification expands quasi-subgenotype A3.

Recently, we proposed a new classification for 'subgenotype A' of hepatitis B virus (HBV), in which the novel 'quasi-subgenotype A3' group comprising HBV 'subgenotype A3', 'tentative A4', and A5 was introduced. Newly 'Tentative subgenotype A7' strains from Cameroon were introduced by Hubschen et al. However, our meticulous phylogenetic analysis demonstrated that these isolates should also be classified into 'quasi-subgenotype A3'. Such misclassification can be avoided by following established principles for HBV subgenotyping. Moreover, their close evolutionary relationship with A3 highlights our hypothesis that geographical origin may be an important factor in further classification of HBV subgenotypes. 2010 The Authors. Clinical Microbiology and Infection; 2010 European Society of Clinical Microbiology and Infectious Diseases.