title: Multiannual patterns of influenza A transmission in Chinese live bird market systems.
abstract: BACKGROUND
  Avian influenza viruses (AIV) cause huge economic losses in poultry industries and pose a substantial threat to human health. However, predicting AIV epizootics and emergence in humans is confounded by insufficient empirical data on the ecology and dynamics of AIV in poultry systems. To address this gap, we quantified incidence patterns for 13 hemagglutinin subtypes of AIV using 6 years of surveillance data that were collected from ten different species of poultry and three different types of poultry holdings (contexts) - retail, wholesale, or farms.
  
  
  METHODS
  We collected 42 646 samples in Shantou, China between 2000 and 2006. We screened samples for hemagglutinin subtypes 1-13 of AIV and Avian Paramyxovirus-type-1 (APMV-1) using monospecific antisera in hemagglutination inhibition tests. We analyzed the data to determine seasonality patterns, subtype-host, and subtype-subtype interactions as well as subtype bias in incidence in different contexts.
  
  
  RESULTS
  H3, H6, H9, and APMV-1 were the most prevalent. No significant seasonality was found when all subtypes were considered together. For most AIV subtypes and APMV-1, there was subtype specificity for host, context, and coinfection partner. H5 showed the most generalized host usage pattern, followed by H9 and H6.
  
  
  CONCLUSIONS
  Subtype-specific patterns because of host, context, and other subtypes suggest that risk assessments that exclude these details are likely inaccurate. Surveillance should include longitudinal sampling of multiple host species in multiple contexts. Quantitative models of control strategies must consider multiple subtypes, hosts, and source contexts to assess the effectiveness of interventions.
authors.affiliation: International Institution of Infection and Immunity, Shantou University Medical College, Shantou, China Colorado State University, Fort Collins, CO, USA.
authors.forename: Kim M
authors.initials: KM
authors.lastname: Pepin
authors.forename: Jia
authors.initials: J
authors.lastname: Wang
authors.forename: Colleen T
authors.initials: CT
authors.lastname: Webb
authors.forename: Gavin J D
authors.initials: GJ
authors.lastname: Smith
authors.forename: Mary
authors.initials: M
authors.lastname: Poss
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hudson
authors.forename: Wenshan
authors.initials: W
authors.lastname: Hong
authors.forename: Huachen
authors.initials: H
authors.lastname: Zhu
authors.forename: Steven
authors.initials: S
authors.lastname: Riley
authors.forename: Yi
authors.initials: Y
authors.lastname: Guan
mesh_terms: D000818:Animals; D002645:Chickens / Q000821:virology; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks; D004372:Ducks / Q000821:virology; D006385:Hemagglutination Inhibition Tests; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000145:classification / Q000235:genetics*; D058507:Host Specificity; D006801:Humans; D015994:Incidence; D009980:Influenza A virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D005585:Influenza in Birds / Q000453:epidemiology / Q000635:transmission* / Q000821:virology; D011200:Poultry / Q000821:virology*; D011201:Poultry Diseases / Q000453:epidemiology / Q000635:transmission* / Q000821:virology; D015995:Prevalence; D013045:Species Specificity
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus