title: [Emerged Pdm09 influenza virus increased purifying selection of seasonal H1N1 influenza virus].
abstract: Pdm09 virus outbreak occurred in Mainland China in May 2009, a few months later, the prevalence of seasonal H1N1(sH1N1) influenza virus that already circulated in human for tens of years began to decline and disappeared afterwards. To identify the reason for the rapid decline of sH1N1 in mainland China, we sequenced the HA1 of sH1N1 during 2006-2011, and then analyzed the selective pressure in different phases. Our results showed before Pdm09 outbreak, the omega value was 0. 36 while after Pdm09 outbreak the omega value was 0. 28 and significant difference (t test, P<0. 05) was identified. We concluded that sH1N1 obtained stronger purifying selection after Pdm09 outbreak in China. This might one of the major reasons causing the disappearance of sH1N1 in human.
authors.affiliation: Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, China CDC, Beijing 102206, China. lanyu@cnic.org.cn
authors.forename: Yu
authors.initials: Y
authors.lastname: Lan
authors.forename: Wei-Juan
authors.initials: WJ
authors.lastname: Huang
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Sui
authors.forename: Xi-Yan
authors.initials: XY
authors.lastname: Li
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhao
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Yao-Yao
authors.initials: YY
authors.lastname: Chen
authors.forename: Jun-Feng
authors.initials: JF
authors.lastname: Guo
authors.forename: Yan-Hui
authors.initials: YH
authors.lastname: Cheng
authors.forename: Min-Ju
authors.initials: MJ
authors.lastname: Tan
authors.forename: Zhao
authors.initials: Z
authors.lastname: Wang
authors.forename: Ning
authors.initials: N
authors.lastname: Xiao
authors.forename: He-Jiang
authors.initials: HJ
authors.lastname: Wei
authors.forename: Da-Yan
authors.initials: DY
authors.lastname: Wang
authors.forename: Yue-Long
authors.initials: YL
authors.lastname: Shu
mesh_terms: D002681:China; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D007251:Influenza, Human / Q000821:virology*; D010802:Phylogeny; D012621:Seasons; D012641:Selection, Genetic