title: The Evolution and Transmission of Epidemic GII.17 Noroviruses.
abstract: In recent decades, the GII.4 norovirus genotype has predominated in epidemics worldwide and been associated with an increased rate of evolutionary change. In 2014, a novel GII.17 variant emerged and persisted, causing large outbreaks of gastroenteritis in China and sporadic infections globally. The origin, evolution, and transmission history of this new variant are largely unknown.
  
  
  
  We generated 103 full capsid and 8 whole-genome sequences of GII.17 strains collected between August 2013 and November 2015 in Guangdong, China. Phylogenetic analyses were performed by integrating our data with those for all publically available GII.17 sequences.
  
  
  
  The novel emergent lineage GII.17_Kawasaki_2014 most likely originated from Africa around 2001 and evolved at a rate of 5.6 × 10(-3) substitutions/site/year. Within this lineage, a new variant containing several important amino acid changes emerged around August 2013 and caused extensive epidemics in 2014-2015. The phylodynamic and epidemic history of the GII.17_Kawasaki lineage shows similarities with the pattern observed for GII.4 norovirus evolution. Virus movements from Hong Kong to neighboring coastal cities were frequently observed.
  
  
  
  Our results provide new insights into GII.17 norovirus evolution and transmission and highlight the potential for a rare norovirus genotype to rapidly replace existing strains and cause local epidemics.
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention Guangdong Provincial Institution of Public Health, Guangzhou, China Department of Zoology.
authors.forename: Jing
authors.initials: J
authors.lastname: Lu
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention.
authors.forename: Lin
authors.initials: L
authors.lastname: Fang
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention.
authors.forename: Huanying
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention.
authors.forename: Jiaqian
authors.initials: J
authors.lastname: Lao
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention.
authors.forename: Fen
authors.initials: F
authors.lastname: Yang
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention.
authors.forename: Limei
authors.initials: L
authors.lastname: Sun
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention Guangdong Provincial Institution of Public Health, Guangzhou, China.
authors.forename: Jianpeng
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention.
authors.forename: Jinyan
authors.initials: J
authors.lastname: Lin
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention.
authors.forename: Tie
authors.initials: T
authors.lastname: Song
authors.affiliation: Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, United Kingdom.
authors.forename: Tao
authors.initials: T
authors.lastname: Ni
authors.affiliation: Department of Zoology.
authors.forename: Jayna
authors.initials: J
authors.lastname: Raghwani
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention.
authors.forename: Changwen
authors.initials: C
authors.lastname: Ke
authors.affiliation: Department of Zoology.
authors.forename: Nuno R
authors.initials: NR
authors.lastname: Faria
authors.affiliation: Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, United Kingdom.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Bowden
authors.affiliation: Department of Zoology.
authors.forename: Oliver G
authors.initials: OG
authors.lastname: Pybus
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
mesh_terms: D000349:Africa; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000635:transmission / Q000821:virology*; D002681:China; D016000:Cluster Analysis; D018562:Disease Transmission, Infectious; D019143:Evolution, Molecular; D014644:Genetic Variation; D005838:Genotype; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D017720:Molecular Epidemiology; D029322:Norovirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
chemical_list: D012367:RNA, Viral
keywords: epidemic; norovirus; phylogenetic; phylogeographic; virus transmission