title: A spatiotemporal model to assess the introduction risk of African horse sickness by import of animals and vectors in France.
abstract: BACKGROUND
  African horse sickness (AHS) is a major, Culicoides-borne viral disease in equines whose introduction into Europe could have dramatic consequences. The disease is considered to be endemic in sub-Saharan Africa. Recent introductions of other Culicoides-borne viruses (bluetongue and Schmallenberg) into northern Europe have highlighted the risk that AHS may arrive in Europe as well. The aim of our study was to provide a spatiotemporal quantitative risk model of AHS introduction into France. The study focused on two pathways of introduction: the arrival of an infectious host (PW-host) and the arrival of an infectious Culicoides midge via the livestock trade (PW-vector). The risk of introduction was calculated by determining the probability of an infectious animal or vector entering the country and the probability of the virus then becoming established: i.e., the virus's arrival in France resulting in at least one local equine host being infected by one local vector. This risk was assessed using data from three consecutive years (2010 to 2012) for 22 regions in France.
  
  
  RESULTS
  The results of the model indicate that the annual risk of AHS being introduced to France is very low but that major spatiotemporal differences exist. For both introduction pathways, risk is higher from July to October and peaks in July. In general, regions with warmer climates are more at risk, as are colder regions with larger equine populations; however, regional variation in animal importation patterns (number and species) also play a major role in determining risk. Despite the low probability that AHSV is present in the EU, intra-EU trade of equines contributes most to the risk of AHSV introduction to France because it involves a large number of horse movements.
  
  
  CONCLUSIONS
  It is important to address spatiotemporal differences when assessing the risk of ASH introduction and thus also when implementing efficient surveillance efforts. The methods and results of this study may help develop surveillance techniques and other risk reduction measures that will prevent the introduction of AHS or minimize AHS' potential impact once introduced, both in France and the rest of Europe.
authors.affiliation: INRA UR346 Animal Epidemiology, Vetagrosup, F-69280, Marcy l'Etoile, France. celine.faverjon@vetagro-sup.fr.
authors.forename: C
authors.initials: C
authors.lastname: Faverjon
authors.affiliation: INRA UR346 Animal Epidemiology et Département Hippique, VetAgroSup, F-69280, Marcy L'Etoile, France. agnes.leblond@vetagro-sup.fr.
authors.forename: A
authors.initials: A
authors.lastname: Leblond
authors.affiliation: ANSES, Direction scientifique des laboratoires - unité Survepi, 94700, Maisons-Alfort, France. pascal.hendrikx@anses.fr.
authors.forename: P
authors.initials: P
authors.lastname: Hendrikx
authors.affiliation: CIRAD, UMR CMAEE, F-34398 Montpellier, France ; INRA, UMR1309 CMAEE, F-34398, Montpellier, France. thomas.balenghien@cirad.fr.
authors.forename: T
authors.initials: T
authors.lastname: Balenghien
authors.affiliation: Central Veterinary Institute, part of Wageningen UR, PO Box 65, 8200 AB, Lelystad, The Netherlands. clazien.devos@wur.nl.
authors.forename: C J
authors.initials: CJ
authors.lastname: de Vos
authors.affiliation: Central Veterinary Institute, part of Wageningen UR, PO Box 65, 8200 AB, Lelystad, The Netherlands. egil.fischer@wur.nl.
authors.forename: E A J
authors.initials: EA
authors.lastname: Fischer
authors.affiliation: Central Veterinary Institute, part of Wageningen UR, PO Box 65, 8200 AB, Lelystad, The Netherlands. aline.dekoeijer@wur.nl.
authors.forename: A A
authors.initials: AA
authors.lastname: de Koeijer
mesh_terms: D000355:African Horse Sickness / Q000191:economics / Q000453:epidemiology / Q000635:transmission*; D000818:Animals; D002417:Cattle; D002519:Ceratopogonidae / Q000502:physiology*; D003132:Commerce; D018397:Equidae; D008954:Models, Biological; D012307:Risk Factors