title: Spatial multi-criteria decision analysis to predict suitability for African swine fever endemicity in Africa.
abstract: BACKGROUND
  African swine fever (ASF) is endemic in several countries of Africa and may pose a risk to all pig producing areas on the continent. Official ASF reporting is often rare and there remains limited awareness of the continent-wide distribution of the disease.In the absence of accurate ASF outbreak data and few quantitative studies on the epidemiology of the disease in Africa, we used spatial multi-criteria decision analysis (MCDA) to derive predictions of the continental distribution of suitability for ASF persistence in domestic pig populations as part of sylvatic or domestic transmission cycles. In order to incorporate the uncertainty in the relative importance of different criteria in defining suitability, we modelled decisions within the MCDA framework using a stochastic approach. The predictive performance of suitability estimates was assessed via a partial ROC analysis using ASF outbreak data reported to the OIE since 2005.
  
  
  RESULTS
  Outputs from the spatial MCDA indicate that large areas of sub-Saharan Africa may be suitable for ASF persistence as part of either domestic or sylvatic transmission cycles. Areas with high suitability for pig to pig transmission ('domestic cycles') were estimated to occur throughout sub-Saharan Africa, whilst areas with high suitability for introduction from wildlife reservoirs ('sylvatic cycles') were found predominantly in East, Central and Southern Africa. Based on average AUC ratios from the partial ROC analysis, the predictive ability of suitability estimates for domestic cycles alone was considerably higher than suitability estimates for sylvatic cycles alone, or domestic and sylvatic cycles in combination.
  
  
  CONCLUSIONS
  This study provides the first standardised estimates of the distribution of suitability for ASF transmission associated with domestic and sylvatic cycles in Africa. We provide further evidence for the utility of knowledge-driven risk mapping in animal health, particularly in data-sparse environments.
authors.affiliation: The Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire AL9 7TA, UK. w.a.de-glanville@sms.ed.ac.uk.
authors.forename: William A
authors.initials: WA
authors.lastname: de Glanville
authors.forename: Laurence
authors.initials: L
authors.lastname: Vial
authors.forename: Solenne
authors.initials: S
authors.lastname: Costard
authors.forename: Barbara
authors.initials: B
authors.lastname: Wieland
authors.forename: Dirk U
authors.initials: DU
authors.lastname: Pfeiffer
mesh_terms: D000349:Africa / Q000453:epidemiology; D000357:African Swine Fever / Q000453:epidemiology*; D000818:Animals; D003661:Decision Support Techniques; D004196:Disease Outbreaks; D019353:Endemic Diseases / Q000662:veterinary*; D008954:Models, Biological; D015203:Reproducibility of Results; D012307:Risk Factors; D013552:Swine