Genetic analysis and evaluation of the reassortment of influenza B viruses isolated in Taiwan during the 2004-2005 and 2006-2007 epidemics.
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.
Jian
Jhih-Wei
JW
National Influenza Center, Centers for Disease Control, Taipei, Taiwan, ROC.
Lai
Cheng-Tsung
CT
Kuo
Chuan-Yi
CY
Kuo
Steve Hsu-Sung
SH
Hsu
Li-Ching
LC
Chen
Pei-Jer
PJ
Wu
Ho-Sheng
HS
Liu
Ming-Tsan
MT
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
D019267:Hemagglutinin Glycoproteins, Influenza Virus; C057959:NA glycoprotein, Influenza B virus; D012367:RNA, Viral; D014764:Viral Proteins; C493831:hemagglutinin HA1, influenza B virus