title: Genetic data provide evidence for wind-mediated transmission of highly pathogenic avian influenza.
abstract: Outbreaks of highly pathogenic avian influenza in poultry can cause severe economic damage and represent a public health threat. Development of efficient containment measures requires an understanding of how these influenza viruses are transmitted between farms. However, the actual mechanisms of interfarm transmission are largely unknown. Dispersal of infectious material by wind has been suggested, but never demonstrated, as a possible cause of transmission between farms. Here we provide statistical evidence that the direction of spread of avian influenza A(H7N7) is correlated with the direction of wind at date of infection. Using detailed genetic and epidemiological data, we found the direction of spread by reconstructing the transmission tree for a large outbreak in the Netherlands in 2003. We conservatively estimate the contribution of a possible wind-mediated mechanism to the total amount of spread during this outbreak to be around 18%.
authors.affiliation: Center for Infectious Disease Control, National Institute of Public Health and the Environment, Bilthoven, The Netherlands. rolf.ypma@rivm.nl
authors.forename: Rolf J F
authors.initials: RJ
authors.lastname: Ypma
authors.forename: Marcel
authors.initials: M
authors.lastname: Jonges
authors.forename: Arnaud
authors.initials: A
authors.lastname: Bataille
authors.forename: Arjan
authors.initials: A
authors.lastname: Stegeman
authors.forename: Guus
authors.initials: G
authors.lastname: Koch
authors.forename: Michiel
authors.initials: M
authors.lastname: van Boven
authors.forename: Marion
authors.initials: M
authors.lastname: Koopmans
authors.forename: W Marijn
authors.initials: WM
authors.lastname: van Ballegooijen
authors.forename: Jacco
authors.initials: J
authors.lastname: Wallinga
mesh_terms: D000818:Animals; D004196:Disease Outbreaks; D053126:Influenza A Virus, H7N7 Subtype / Q000235:genetics / Q000302:isolation & purification*; D005585:Influenza in Birds / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D017720:Molecular Epidemiology; D009426:Netherlands / Q000453:epidemiology; D011200:Poultry; D011201:Poultry Diseases / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D012367:RNA, Viral / Q000235:genetics; D014919:Wind
chemical_list: D012367:RNA, Viral