title: Modelling hotspots of the two dominant Rift Valley fever vectors (Aedes vexans and Culex poicilipes) in Barkédji, Sénégal.
abstract: BACKGROUND
  Climatic and environmental variables were used successfully by using models to predict Rift Valley fever (RVF) virus outbreaks in East Africa. However, these models are not replicable in the West African context due to a likely difference of the dynamic of the virus emergence. For these reasons specific models mainly oriented to the risk mapping have been developed. Hence, the areas of high vector pressure or virus activity are commonly predicted. However, the factors impacting their occurrence are poorly investigated and still unknown. In this study, we examine the impact of climate and environmental factors on the likelihood of occurrence of the two main vectors of RVF in West Africa (Aedes vexans and Culex poicilipes) hotspots.
  
  
  METHODS
  We used generalized linear mixed models taking into account spatial autocorrelation, in order to overcome the default threshold for areas with high mosquito abundance identified by these models. Getis' Gi*(d) index was used to define local adult mosquito abundance clusters (hotspot).
  
  
  RESULTS
  For Culex poicilipes, a decrease of the minimum temperature promotes the occurrence of hotspots, whereas, for Aedes vexans, the likelihood of hotspot occurrence is negatively correlated with relative humidity, maximum and minimum temperatures. However, for the two vectors, proximity to ponds would increase the risk of being in an hotspot area.
  
  
  CONCLUSIONS
  These results may be useful in the improvement of RVF monitoring and vector control management in the Barkedji area.
authors.affiliation: Unité d'Entomologie Médicale, Institut Pasteur de Dakar, B.P. 220, Dakar, Sénégal. ctalla@pasteur.sn.|Laboratoire d'Etudes et de Recherches en Statistiques et Développement, Université Gaston Berger, Saint-Louis, Sénégal. ctalla@pasteur.sn.
authors.forename: Cheikh
authors.initials: C
authors.lastname: Talla
authors.affiliation: Unité d'Entomologie Médicale, Institut Pasteur de Dakar, B.P. 220, Dakar, Sénégal. ddiallo@pasteur.sn.
authors.forename: Diawo
authors.initials: D
authors.lastname: Diallo
authors.affiliation: Unité d'Entomologie Médicale, Institut Pasteur de Dakar, B.P. 220, Dakar, Sénégal. dia@pasteur.sn.
authors.forename: Ibrahima
authors.initials: I
authors.lastname: Dia
authors.affiliation: Unité d'Entomologie Médicale, Institut Pasteur de Dakar, B.P. 220, Dakar, Sénégal. ba@pasteur.sn.
authors.forename: Yamar
authors.initials: Y
authors.lastname: Ba
authors.affiliation: Centre de Suivi Ecologique, Dakar, Sénégal. jacques-andre.ndione@cse.sn.
authors.forename: Jacques-André
authors.initials: JA
authors.lastname: Ndione
authors.affiliation: School of Environmental Sciences, University of Liverpool, Liverpool, UK. a.p.morse@live.ac.uk.|National Health Service, National Institute of Health Research, Health Protection Research Unit in Emerging and Zoonotic Infections, Liverpool, UK. a.p.morse@live.ac.uk.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Morse
authors.affiliation: Laboratoire d'Etudes et de Recherches en Statistiques et Développement, Université Gaston Berger, Saint-Louis, Sénégal. aliou.diop@ugb.edu.sn.
authors.forename: Aliou
authors.initials: A
authors.lastname: Diop
authors.affiliation: Unité d'Entomologie Médicale, Institut Pasteur de Dakar, B.P. 220, Dakar, Sénégal. diallo@pasteur.sn.
authors.forename: Mawlouth
authors.initials: M
authors.lastname: Diallo
mesh_terms: D000330:Aedes / Q000254:growth & development*; D000818:Animals; D002980:Climate; D003465:Culex / Q000254:growth & development*; D004777:Environment; D006813:Humidity; D007303:Insect Vectors; D012675:Senegal; D013696:Temperature