title: Laboratory-based surveillance and molecular epidemiology of influenza virus in Taiwan.
abstract: A laboratory-based surveillance network of 11 clinical virological laboratories for influenza viruses was established in Taiwan under the coordination of the Center for Disease Control and Prevention (CDC), Taiwan. From October 2000 to March 2004, 3,244 influenza viruses were isolated, including 1,969 influenza A and 1,275 influenza B viruses. The influenza infections usually occurred frequently in winter in the northern hemisphere. However, the influenza seasonality in Taiwan was not clear during the four seasons under investigation. For example, the influenza A viruses peaked during the winters of 2001, 2002, and 2003. However, some isolated peaks were also found in the summer and fall (June to November) of 2001 and 2002. An unusual peak of influenza B also occurred in the summer of 2002 (June to August). Phylogenetic analysis shows that influenza A isolates from the same year were often grouped together. However, influenza B isolates from the year 2002 clustered into different groups, and the data indicate that both B/Victoria/2/87-like and B/Yamagata/16/88-like lineages of influenza B viruses were cocirculating. Sequence comparison of epidemic strains versus vaccine strains shows that many vaccine-like Taiwanese strains were circulating at least 2 years before the vaccine strains were introduced. No clear seasonality of influenza reports in Taiwan occurred in contrast to other more continental regions.
authors.affiliation: Chang Gung Memorial Hospital & Chang Gung University, Taipei, Taiwan.
authors.forename: Shin-Ru
authors.initials: SR
authors.lastname: Shih
authors.forename: Guang-Wu
authors.initials: GW
authors.lastname: Chen
authors.forename: Ching-Chun
authors.initials: CC
authors.lastname: Yang
authors.forename: Weng-Zhi
authors.initials: WZ
authors.lastname: Yang
authors.forename: Ding-Ping
authors.initials: DP
authors.lastname: Liu
authors.forename: Jih-Hui
authors.initials: JH
authors.lastname: Lin
authors.forename: Shu-Chun
authors.initials: SC
authors.lastname: Chiu
authors.forename: Haur-Young
authors.initials: HY
authors.lastname: Chen
authors.forename: Kuo-Chien
authors.initials: KC
authors.lastname: Tsao
authors.forename: Chung-Guei
authors.initials: CG
authors.lastname: Huang
authors.forename: Ya-Ling
authors.initials: YL
authors.lastname: Huang
authors.forename: Chee-Keng
authors.initials: CK
authors.lastname: Mok
authors.forename: Chi-Jene
authors.initials: CJ
authors.lastname: Chen
authors.forename: Tzou-Yien
authors.initials: TY
authors.lastname: Lin
authors.forename: Jen-Ren
authors.initials: JR
authors.lastname: Wang
authors.forename: Chuan-Liang
authors.initials: CL
authors.lastname: Kao
authors.forename: Kwei-Hsian
authors.initials: KH
authors.lastname: Lin
authors.forename: Li-Kuang
authors.initials: LK
authors.lastname: Chen
authors.forename: Hock-Liew
authors.initials: HL
authors.lastname: Eng
authors.forename: Yung-Ching
authors.initials: YC
authors.lastname: Liu
authors.forename: Po-Yen
authors.initials: PY
authors.lastname: Chen
authors.forename: Jen-Shiou
authors.initials: JS
authors.lastname: Lin
authors.forename: Jen-Hsien
authors.initials: JH
authors.lastname: Wang
authors.forename: Cheng-Wen
authors.initials: CW
authors.lastname: Lin
authors.forename: Yu-Jiun
authors.initials: YJ
authors.lastname: Chan
authors.forename: Jang-Jih
authors.initials: JJ
authors.lastname: Lu
authors.forename: Chao A
authors.initials: CA
authors.lastname: Hsiung
authors.forename: Pei-Jer
authors.initials: PJ
authors.lastname: Chen
authors.forename: Ih-Jen
authors.initials: IJ
authors.lastname: Su
mesh_terms: D000818:Animals; D004285:Dogs; D006801:Humans; D009980:Influenza A virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D009981:Influenza B virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology; D007753:Laboratories; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D018571:Sentinel Surveillance; D017422:Sequence Analysis, DNA; D013624:Taiwan / Q000453:epidemiology; D014773:Virology