title: Culicidae diversity, malaria transmission and insecticide resistance alleles in malaria vectors in Ouidah-Kpomasse-Tori district from Benin (West Africa): A pre-intervention study.
abstract: BACKGROUND
  To implement an Insecticide Resistance Management (IRM) strategy through a randomized controlled trial (phase III), 28 villages were selected in southern Benin. No recent entomological data being available in these villages, entomological surveys were performed between October 2007 and May 2008, before vector control strategies implementation, to establish baseline data.
  
  
  METHODS
  Mosquitoes were sampled by human landing collection (16 person-nights per village per survey per village) during 5 surveys. Mosquitoes were identified morphologically and by molecular methods. The Plasmodium falciparum circumsporozoïte indexes were measured by ELISA, and the entomological inoculation rates (EIRs) were calculated. Molecular detection of pyrethroid knock down resistance (Kdr) and of insensitive acetylcholinesterase were performed.
  
  
  RESULTS
  44,693 mosquitoes belonging to 28 different species were caught from October 2007 to May 2008. Among mosquitoes caught, 318 were An. gambiae s.s., 2 were An. nili, 568 were An. funestus s.s., and one individual was An. leesoni. EIR was 2.05 ± 1.28 infective bites per human per 100 nights on average, of which 0.67 ± 0.60 were from An. funestus and 1.38 ± 0.94 infective bites were from An. gambiae. Important variations were noted between villages considering mosquito density and malaria transmission indicating a spatial heterogeneity in the study area. The kdr allelic frequency was 28.86% in An. gambiae s.s. on average and significantly increases from October 2007 (10.26%) to May 2008 (33.87%) in M molecular form of An. gambiae s.s. Ace 1 mutation was found in S molecular of An. gambiae s.s at a low frequency (< 1%).
  
  
  CONCLUSIONS
  This study updates information on mosquito diversity and malaria risk in rural villages from south Benin. It showed a high spatial heterogeneity in mosquito distribution and malaria transmission and underlines the need of further investigations of biological, ecological, and behavioral traits of malaria vectors species and forms. This study is a necessary prerequisite to cartography malaria risk and to improve vector control operations in southern Benin.
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Bénin. armeldj@yahoo.fr.
authors.forename: Armel
authors.initials: A
authors.lastname: Djènontin
authors.forename: Sahabi
authors.initials: S
authors.lastname: Bio-Bangana
authors.forename: Nicolas
authors.initials: N
authors.lastname: Moiroux
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Henry
authors.forename: Olayidé
authors.initials: O
authors.lastname: Bousari
authors.forename: Joseph
authors.initials: J
authors.lastname: Chabi
authors.forename: Razaki
authors.initials: R
authors.lastname: Ossè
authors.forename: Sébastien
authors.initials: S
authors.lastname: Koudénoukpo
authors.forename: Vincent
authors.initials: V
authors.lastname: Corbel
authors.forename: Martin
authors.initials: M
authors.lastname: Akogbéto
authors.forename: Fabrice
authors.initials: F
authors.lastname: Chandre
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