title: Genetic analysis and evaluation of the reassortment of influenza B viruses isolated in Taiwan during the 2004-2005 and 2006-2007 epidemics.
abstract: Influenza B viruses were predominant in Taiwan during the 2004-2005 epidemic and both Victoria and Yamagata lineage viruses co-circulated. A reassortant influenza B virus that contained a Victoria lineage hemagglutinin (HA) gene and Yamagata lineage neuraminidase (NA) gene appeared first in 2002 and became predominant during the 2004-2005 epidemic. During the 2006-2007 epidemic, an influenza B outbreak occurred in Taiwan and only Victoria lineage viruses circulated. We characterized the viruses isolated in the 2006-2007 epidemic and found that the HA genes of influenza B viruses from that epidemic were highly similar to those from the 2004-2005 epidemic. We also analyzed the NA genes of isolates from the 2006-2007 epidemic and found that they all belonged to the Yamagata lineage and formed a new genetic subclade. Comparison of isolates from the 2004-2005 and 2006-2007 epidemics revealed four substitutions, N220K, E320D, K343R and E404K in NA genes. Although the HA sequences from the 2006-2007 epidemic were similar to those from the 2004-2005 epidemic, the NA sequences differed, suggesting distinct patterns of evolution of the HA and NA genes from 2004-2007 in Taiwan. This study emphasizes that the evolution of the NA genes may contribute to reemergence of influenza B viruses.
authors.affiliation: National Influenza Center, Centers for Disease Control, Taipei, Taiwan, ROC.
authors.forename: Jhih-Wei
authors.initials: JW
authors.lastname: Jian
authors.forename: Cheng-Tsung
authors.initials: CT
authors.lastname: Lai
authors.forename: Chuan-Yi
authors.initials: CY
authors.lastname: Kuo
authors.forename: Steve Hsu-Sung
authors.initials: SH
authors.lastname: Kuo
authors.forename: Li-Ching
authors.initials: LC
authors.lastname: Hsu
authors.forename: Pei-Jer
authors.initials: PJ
authors.lastname: Chen
authors.forename: Ho-Sheng
authors.initials: HS
authors.lastname: Wu
authors.forename: Ming-Tsan
authors.initials: MT
authors.lastname: Liu
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D004196:Disease Outbreaks; D019143:Evolution, Molecular; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D006801:Humans; D009981:Influenza B virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013624:Taiwan / Q000453:epidemiology; D014764:Viral Proteins / Q000235:genetics
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; C057959:NA glycoprotein, Influenza B virus; D012367:RNA, Viral; D014764:Viral Proteins; C493831:hemagglutinin HA1, influenza B virus