title: The role of live poultry movement and live bird market biosecurity in the epidemiology of influenza A (H7N9): A cross-sectional observational study in four eastern China provinces.
abstract: BACKGROUND
  A new reassortant influenza A (H7N9) virus emerged early 2013 in eastern China. Exposure to H7N9 infected poultry at live bird markets (LBM) was implicated as the main risk factor for human infection. We aimed to identify the role of LBM biosecurity indicators and poultry movement in the affected areas.
  
  
  METHODS
  A cross-sectional survey was carried out in 24 LBMs at the beginning of H7N9 outbreak in all affected provinces. We used univariable analysis to identify the biosecurity factors associated with the H7N9 presence in LBMs and social network and spatial analysis to quantify the connectivity and geographic variation in the connectivity of poultry movements.
  
  
  RESULTS
  Chickens were the predominant poultry species traded by affected LBMs. The presence of H7N9 in LBMs was significantly associated with the type of LBM and with LBMs that sold chicken to other markets. The chicken movements were significantly spatially clustered and was highest in counties from Jiangsu and Anhui provinces.
  
  
  CONCLUSIONS
  LBM biosecurity and chicken movement played an important role in the emergence of H7N9. This study identified highly connected areas in eastern China which continue to report human infections highlighting candidate areas for more detailed epidemiological investigations.
authors.affiliation: School of Veterinary Science, The University of Queensland, Australia; Food and Agriculture Organization of the United Nations (FAO), PR China. Electronic address: xiaoyan.zhou@uq.edu.au.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Food and Agriculture Organization of the United Nations (FAO), PR China; China Animal Health and Epidemiology Centre, Ministry of Agriculture, PR China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Li
authors.affiliation: China Animal Health and Epidemiology Centre, Ministry of Agriculture, PR China.
authors.forename: Youming
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Veterinary Science, The University of Queensland, Australia; Food and Agriculture Organization of the United Nations (FAO), PR China.
authors.forename: John
authors.initials: J
authors.lastname: Edwards
authors.affiliation: Food and Agriculture Organization of the United Nations (FAO), PR China.
authors.forename: Fusheng
authors.initials: F
authors.lastname: Guo
authors.affiliation: Research School of Population Health, The Australian National University, Australia.
authors.forename: Archie C A
authors.initials: AC
authors.lastname: Clements
authors.affiliation: China Animal Health and Epidemiology Centre, Ministry of Agriculture, PR China.
authors.forename: Baoxu
authors.initials: B
authors.lastname: Huang
authors.affiliation: School of Veterinary Science, The University of Queensland, Australia; Child Health Research Centre, School of Medicine, The University of Queensland, Australia.
authors.forename: Ricardo J Soares
authors.initials: RJ
authors.lastname: Magalhaes
mesh_terms: D000818:Animals; D002645:Chickens / Q000821:virology*; D002681:China / Q000453:epidemiology; D003132:Commerce; D003430:Cross-Sectional Studies; D004196:Disease Outbreaks; D062305:Geographic Mapping; D062306:Geography, Medical; D006801:Humans; D064766:Influenza A Virus, H7N9 Subtype; D005585:Influenza in Birds / Q000453:epidemiology* / Q000635:transmission / Q000821:virology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology; D012307:Risk Factors; D062206:Spatial Analysis; D015047:Zoonoses / Q000821:virology*
keywords: Biosecurity; Influenza A (H7N9); Live bird markets; Meat chicken; Poultry movement; Social network analysis