title: Avian influenza A virus (H7N7) epidemic in The Netherlands in 2003: course of the epidemic and effectiveness of control measures.
abstract: An epidemic of high-pathogenicity avian influenza (HPAI) A virus subtype H7N7 occurred in The Netherlands in 2003 that affected 255 flocks and led to the culling of 30 million birds. To evaluate the effectiveness of the control measures, we quantified between-flock transmission characteristics of the virus in 2 affected areas, using the reproduction ratio Rh. The control measures markedly reduced the transmission of HPAI virus: Rh before detection of the outbreak in the first infected flock was 6.5 (95% confidence interval [CI], 3.1-9.9) in one area and 3.1 in another area, and it decreased to 1.2 (95% CI, 0.6-1.9) after detection of the first outbreak in both areas. The observation that Rh remained >1 suggests that the containment of the epidemic was probably due to the reduction in the number of susceptible flocks by complete depopulation of the infected areas rather than to the reduction of the transmission by the other control measures.
authors.affiliation: Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. j.a.stegeman@vet.uu.nl
authors.forename: Arjan
authors.initials: A
authors.lastname: Stegeman
authors.forename: Annemarie
authors.initials: A
authors.lastname: Bouma
authors.forename: Armin R W
authors.initials: AR
authors.lastname: Elbers
authors.forename: Mart C M
authors.initials: MC
authors.lastname: de Jong
authors.forename: Gonnie
authors.initials: G
authors.lastname: Nodelijk
authors.forename: Fred
authors.initials: F
authors.lastname: de Klerk
authors.forename: Guus
authors.initials: G
authors.lastname: Koch
authors.forename: Michiel
authors.initials: M
authors.lastname: van Boven
mesh_terms: D000818:Animals; D004196:Disease Outbreaks / Q000517:prevention & control / Q000662:veterinary*; D053126:Influenza A Virus, H7N7 Subtype; D009980:Influenza A virus / Q000302:isolation & purification*; D005585:Influenza in Birds / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D015233:Models, Statistical; D009426:Netherlands / Q000453:epidemiology; D011200:Poultry