title: Socio-economic and Climate Factors Associated with Dengue Fever Spatial Heterogeneity: A Worked Example in New Caledonia.
abstract: OBJECTIVE
  Understanding the factors underlying the spatio-temporal distribution of infectious diseases provides useful information regarding their prevention and control. Dengue fever spatio-temporal patterns result from complex interactions between the virus, the host, and the vector. These interactions can be influenced by environmental conditions. Our objectives were to analyse dengue fever spatial distribution over New Caledonia during epidemic years, to identify some of the main underlying factors, and to predict the spatial evolution of dengue fever under changing climatic conditions, at the 2100 horizon.
  
  
  METHODS
  We used principal component analysis and support vector machines to analyse and model the influence of climate and socio-economic variables on the mean spatial distribution of 24,272 dengue cases reported from 1995 to 2012 in thirty-three communes of New Caledonia. We then modelled and estimated the future evolution of dengue incidence rates using a regional downscaling of future climate projections.
  
  
  RESULTS
  The spatial distribution of dengue fever cases is highly heterogeneous. The variables most associated with this observed heterogeneity are the mean temperature, the mean number of people per premise, and the mean percentage of unemployed people, a variable highly correlated with people's way of life. Rainfall does not seem to play an important role in the spatial distribution of dengue cases during epidemics. By the end of the 21st century, if temperature increases by approximately 3 °C, mean incidence rates during epidemics could double.
  
  
  CONCLUSIONS
  In New Caledonia, a subtropical insular environment, both temperature and socio-economic conditions are influencing the spatial spread of dengue fever. Extension of this study to other countries worldwide should improve the knowledge about climate influence on dengue burden and about the complex interplay between different factors. This study presents a methodology that can be used as a step by step guide to model dengue spatial heterogeneity in other countries.
authors.affiliation: Epidemiology of Infectious Diseases, Institut Pasteur, Noumea, New Caledonia.|UMR 228, ESPACE-DEV, Institute for Research and Development (IRD), Noumea, New Caledonia.|UMR 182, LOCEAN, Institute for Research and Development (IRD), Noumea, New Caledonia.
authors.forename: Magali
authors.initials: M
authors.lastname: Teurlai
authors.affiliation: UMR 182, LOCEAN, Institute for Research and Development (IRD), Noumea, New Caledonia.
authors.forename: Christophe Eugène
authors.initials: CE
authors.lastname: Menkès
authors.affiliation: Météo-France, Noumea, New Caledonia.
authors.forename: Virgil
authors.initials: V
authors.lastname: Cavarero
authors.affiliation: UMR 182, Laboratoire d'Océanographie et du Climat, Expérimentation et Approches Numériques (LOCEAN), Institute for Research and Development (IRD), Paris, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Degallier
authors.affiliation: Department of Internal Medicine and Infectious Diseases, Territorial Hospital Centre, Noumea, New Caledonia.
authors.forename: Elodie
authors.initials: E
authors.lastname: Descloux
authors.affiliation: Health Department, Direction of Health and Social Affairs of New Caledonia, Noumea, New Caledonia.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Grangeon
authors.affiliation: Medical Entomology, Institut Pasteur, Noumea, New Caledonia.
authors.forename: Laurent
authors.initials: L
authors.lastname: Guillaumot
authors.affiliation: UMR 228, ESPACE-DEV, Université de Montpellier II, IRD, Montpellier, France.
authors.forename: Thérèse
authors.initials: T
authors.lastname: Libourel
authors.affiliation: Centro de Ciências Exatas e da Terra (CCET), Universidade Federal do Rio Grande do Norte (UFRN), Campus Universitário-Lagoa Nova, Brazil.
authors.forename: Paulo Sergio
authors.initials: PS
authors.lastname: Lucio
authors.affiliation: UMR 224 MIVEGEC, Institute for Research and Development (IRD), Noumea, New Caledonia.
authors.forename: Françoise
authors.initials: F
authors.lastname: Mathieu-Daudé
authors.affiliation: UMR 228, ESPACE-DEV, Université de Montpellier II, IRD, Montpellier, France.
authors.forename: Morgan
authors.initials: M
authors.lastname: Mangeas
mesh_terms: D000330:Aedes / Q000821:virology*; D000818:Animals; D002980:Climate; D057231:Climate Change; D003715:Dengue / Q000453:epidemiology*; D004777:Environment; D058872:Epidemics; D005260:Female; D006801:Humans; D015994:Incidence; D007303:Insect Vectors / Q000821:virology*; D008954:Models, Biological; D015999:Multivariate Analysis; D009510:New Caledonia / Q000453:epidemiology; D011891:Rain; D012959:Socioeconomic Factors; D062206:Spatial Analysis; D013696:Temperature