title: Climate change projections of West Nile virus infections in Europe: implications for blood safety practices.
abstract: BACKGROUND
  West Nile virus (WNV) is transmitted by mosquitoes in both urban as well as in rural environments and can be pathogenic in birds, horses and humans. Extrinsic factors such as temperature and land use are determinants of WNV outbreaks in Europe, along with intrinsic factors of the vector and virus.
  
  
  METHODS
  With a multivariate model for WNV transmission we computed the probability of WNV infection in 2014, with July 2014 temperature anomalies. We applied the July temperature anomalies under the balanced A1B climate change scenario (mix of all energy sources, fossil and non-fossil) for 2025 and 2050 to model and project the risk of WNV infection in the future. Since asymptomatic infections are common in humans (which can result in the contamination of the donated blood) we estimated the predictive prevalence of WNV infections in the blood donor population.
  
  
  RESULTS
  External validation of the probability model with 2014 cases indicated good prediction, based on an Area Under Curve (AUC) of 0.871 (SD = 0.032), on the Receiver Operating Characteristic Curve (ROC). The climate change projections for 2025 reveal a higher probability of WNV infection particularly at the edges of the current transmission areas (for example in Eastern Croatia, Northeastern and Northwestern Turkey) and an even further expansion in 2050. The prevalence of infection in (blood donor) populations in the outbreak-affected districts is expected to expand in the future.
  
  
  CONCLUSIONS
  Predictive modelling of environmental and climatic drivers of WNV can be a valuable tool for public health practice. It can help delineate districts at risk for future transmission. These areas can be subjected to integrated disease and vector surveillance, outreach to the public and health care providers, implementation of personal protective measures, screening of blood donors, and vector abatement activities.
authors.affiliation: European Centre for Disease Prevention and Control, Stockholm,, SE-171 83, Sweden. Jan.Semenza@ecdc.europa.eu.
authors.forename: Jan C
authors.initials: JC
authors.lastname: Semenza
authors.affiliation: CIRAD, UPR Animal et Gestion Intégrée des Risques, Montpellier,, F-34093, France. annelise.tran@cirad.fr.
authors.forename: Annelise
authors.initials: A
authors.lastname: Tran
authors.affiliation: European Centre for Disease Prevention and Control, Stockholm,, SE-171 83, Sweden. Laura.Espinosa@ecdc.europa.eu.
authors.forename: Laura
authors.initials: L
authors.lastname: Espinosa
authors.affiliation: European Centre for Disease Prevention and Control, Stockholm,, SE-171 83, Sweden. Bertrand.Sudre@ecdc.europa.eu.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Sudre
authors.affiliation: European Centre for Disease Prevention and Control, Stockholm,, SE-171 83, Sweden. Dragoslav.Domanovic@ecdc.europa.eu.
authors.forename: Dragoslav
authors.initials: D
authors.lastname: Domanovic
authors.affiliation: Department of Geography and Environmental Studies, University of Haifa, Mt. Carmel, Haifa,, 31905, Israel. shlomit@geo.haifa.ac.il.
authors.forename: Shlomit
authors.initials: S
authors.lastname: Paz
mesh_terms: D001782:Blood Donors / Q000706:statistics & numerical data; D058731:Blood Safety / Q000592:standards; D001803:Blood Transfusion / Q000706:statistics & numerical data; D057231:Climate Change; D062665:Epidemiological Monitoring; D005060:Europe / Q000453:epidemiology; D006801:Humans; D008962:Models, Theoretical; D015995:Prevalence; D014901:West Nile Fever / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D014902:West Nile virus / Q000502:physiology