title: Distribution and diversity of the vectors of Rift Valley fever along the livestock movement routes in the northeastern and coastal regions of Kenya.
abstract: BACKGROUND
  Knowledge of vector ecology is important in understanding the transmission dynamics of vector borne disease. In this study, we determined the distribution and diversity of mosquitoes along the major nomadic livestock movement routes (LMR) in the traditional pastoral ecozone of northeastern Kenya. We focused on the vectors of Rift Valley fever virus (RVFv) with the aim of understanding their ecology and how they can potentially influence the circulation of RVFv.
  
  
  METHODS
  Mosquito surveys were conducted during the short and long rainy seasons from November 2012 to August 2014 using CO2-baited CDC light traps at seven sites selected for their proximity to stopover points that provide pasture, water and night bomas (where animals spend nights). We compared mosquito abundance and diversity across the sites, which were located in three ecological zones (IV, V and VI), based on the classification system of agro-ecological zones in Kenya.
  
  
  RESULTS
  Over 31,000 mosquitoes were trapped comprising 21 species belonging to 6 genera. Overall mosquito abundance varied significantly by ecological zones and sites. Mansonia species (Ma. uniformis and Ma. africana) were predominant (n = 12,181, 38.3%). This was followed by the primary RVF vectors, Ae. ochraceus and Ae. mcintoshi comprising 17.9 and 14.98%, respectively, of the total captures and represented across all sites and ecological zones. The Shannon diversity index ranged from 0.8 to 2.4 with significant zone, site and seasonal variations. There was also significant species richness of RVF vector across ecological zones.
  
  
  CONCLUSIONS
  Our findings highlight differential occurrence of RVFv vectors across ecological zones and sampling sites, which may be important in determining areas at risk of emergence and circulation of RVFv. Moreover, the vector distribution map along LMR generated in this study will guide potential interventions for control of the disease, including strategic vaccination for livestock.
authors.affiliation: International Centre of Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi, Kenya. sokello@icipe.org.|Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Pretoria, Hatfield, 0083, South Africa. sokello@icipe.org.
authors.forename: Samwel O
authors.initials: SO
authors.lastname: Arum
authors.affiliation: Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Pretoria, Hatfield, 0083, South Africa. cwweldon@zoology.up.ac.za.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Weldon
authors.affiliation: International Centre of Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi, Kenya. borindi@icipe.org.
authors.forename: Benedict
authors.initials: B
authors.lastname: Orindi
authors.affiliation: International Centre of Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi, Kenya. tlandmann@icipe.org.
authors.forename: Tobias
authors.initials: T
authors.lastname: Landmann
authors.affiliation: International Centre of Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi, Kenya. dtchouassi@icipe.org.
authors.forename: David P
authors.initials: DP
authors.lastname: Tchouassi
authors.affiliation: International Centre of Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi, Kenya. haffognon@icipe.org.
authors.forename: Hippolyte D
authors.initials: HD
authors.lastname: Affognon
authors.affiliation: International Centre of Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi, Kenya. rsang@icipe.org.
authors.forename: Rosemary
authors.initials: R
authors.lastname: Sang
mesh_terms: D025041:Animal Migration; D000818:Animals; D044822:Biodiversity; D009033:Culicidae / Q000145:classification / Q000502:physiology*; D007303:Insect Vectors / Q000145:classification / Q000502:physiology*; D007630:Kenya; D058751:Livestock / Q000502:physiology / Q000821:virology; D012295:Rift Valley Fever / Q000635:transmission* / Q000821:virology; D012296:Rift Valley fever virus / Q000502:physiology