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Volume 37, Number 3, June 2004

Phylogenetic analysis of influenza B virus in Taiwan, 1997 to 2001

Chi-Ho Chan, You Chan, Happy-K Shieh, Cheng-Hsien Tsai, Chia-Yuan Chen, Shu-Chih Liu, Wu-Tse Liu
Department of Microbiology and Immunology, Chung Shan Medical University, Taichung; Department of Veterinary Medicine, National Chung Hsing University, Taichung; Division of Clinical Virology, Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei; Institute of Biotechnology in Medicine, School of Medical Technology and Engineering, National Yang Ming University, Taipei; Department of Pediatrics, Chung Shan Medical University Hospital, Taichung; and The Examination Yuan, Taipei, Taiwan, ROC

Received: September 4, 2003    Revised: October 30, 2003    Accepted: December 15, 2003   


Corresponding author:

Prof. W. T. Liu, No.1, Shih Yuan Road, Wenshan District, Taipei, Taiwan 116, ROC. E-mail: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it



Seventeen strains of influenza B virus were isolated and identified from 1997 to 2001. Throat swabs were collected in children who presented in medical centers in both central and northern parts of Taiwan. To clarify the molecular characteristics of these isolates, both partial hemagglutinin (HA) gene and nonstructural (NS) gene nucleotide sequences were cloned and subjected to nucleotide sequence analysis. The phylogenetic analysis of the HA gene revealed that 16 out of 17 strains were similar to B/Yamagata/16/88-like virus, but grouped together to form an independent cluster. Only one strain, B/Taiwan/21706/97, was similar to the B/Victoria/2/87-like lineage. In addition, all isolates, except for B/Taiwan/21706/97, were similar to B/Beijing/184/93 and B/Yamanashi/166/98, which were chosen as the recommended vaccine strains in 1999 and 2001. In contrast, the NS gene of these isolates was evolved from B/Guangdong/8/93. Based on the accumulation of antigenic drift in our isolates, we conclude that influenza B virus is still prevalent in Taiwan and the accumulation of nucleotide mutations indicated that our isolates form a new cluster that evolved from the YA88 lineage.


Key words:

Antigenic variation, disease outbreaks, evolution, genetic recombination, influenza B virus



J Microbiol Immunol Infect 2004;37:135-144.