title: Insecticide resistance status in Culex quinquefasciatus in Benin.
abstract: BACKGROUND
  Culex quinquefasciatus, an arboviral and filarial vector, is present year round in several cities of the Republic of Benin. There is more information on the resistance status to malaria vectors compared to Culicines. It is therefore unfortunate that the international focus is on Anopheles control and not so much done against Cx. quinquefasciatus, a rather more resilient mosquito to many insecticides that deserves attention. The present study aims to assess the resistance status of Cx. quinquefasciatus to carbamates, pyrethroids and organochlorine and discuss the implications for vector control in four contrasting localities of the country.
  
  
  METHODS
  Four contrasting localities of the country were selected for mosquito collection during the dry season based on their variation in agricultural production, use of insecticides and/or ecological settings. Bioassay were performed on adults collected from the field to assess the susceptibility of Cx. quinquefasciatus to insecticide-impregnated papers (permethrin 0.75%, delthamethrin 0.05%, DDT 4%, and bendiocarb 0.1%) following WHOPES guidelines. Molecular assays were carried out to detect the presence of knock down resistance (kdr) and acetylcholinesterase (ace. 1) mutations in surviving specimens using PCR techniques.
  
  
  RESULTS
  WHO diagnostic tests showed high frequency of resistance in Cx. quinquefasciatus to permethrin (ranging from 4 to 24% mortality), deltamethrin (24 to 48%), DDT (4 to 12%) and bendiocarb (60 to 76%) in the four selected areas. This was consistent with the presence of target site insensitivity due to kdr and ace.1 mutations, which were significantly higher in areas where farmers used insecticides for pests control than in areas where no insecticides were used (p < 0.05.).
  
  
  CONCLUSIONS
  These findings showed that wild populations of Cx. quinquefasciatus have developed resistance against pyrethroids, organochlorine and carbamate. This situation of resistance may seriously jeopardize the efficacy of Insecticide Residual Spray (IRS) and Long-Lasting Insecticide nets (LLINs) on which, most African countries including Benin, rely to reduce malaria transmission.
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, République du Bénin. anges33@yahoo.fr.|Ecole Normale Supérieure de Natitingou-Université de Parakou, Parakou, Benin. anges33@yahoo.fr.
authors.forename: Agnes
authors.initials: A
authors.lastname: Yadouléton
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, République du Bénin. kefilathbadirou@yahoo.fr.
authors.forename: Kefilath
authors.initials: K
authors.lastname: Badirou
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, République du Bénin. ramloving@yahoo.fr.
authors.forename: Ramziath
authors.initials: R
authors.lastname: Agbanrin
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemmorrhagic Fever Reference and Research, Bernhard-Nocht-Strasse 74, Hamburg, Germany. hanna.joest@gmx.de.|German Centre for Infection Research, partner site Hamburg-Luebeck-Borstel, Hamburg, Germany. hanna.joest@gmx.de.
authors.forename: Hanna
authors.initials: H
authors.lastname: Jöst
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, République du Bénin. ermyon2012@yahoo.fr.
authors.forename: Roseline
authors.initials: R
authors.lastname: Attolou
authors.affiliation: AVRDC-The World Vegetable Center, Shanhua, Tainan, 74151, Taiwan. srini.ramasamy@worldveg.org.
authors.forename: Ramasamy
authors.initials: R
authors.lastname: Srinivasan
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, République du Bénin. pagergil@yahoo.fr.|Université d'Abomey-Calavi, Faculté des Sciences et Techniques, Cotonou, Benin. pagergil@yahoo.fr.
authors.forename: Gil
authors.initials: G
authors.lastname: Padonou
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, République du Bénin. akogbetom@yahoo.fr.|Université d'Abomey-Calavi, Faculté des Sciences et Techniques, Cotonou, Benin. akogbetom@yahoo.fr.
authors.forename: Martin
authors.initials: M
authors.lastname: Akogbéto
mesh_terms: D063147:Animal Distribution; D000818:Animals; D001541:Benin; D003465:Culex / Q000145:classification / Q000187:drug effects*; D005260:Female; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D009154:Mutation; D016133:Polymerase Chain Reaction
chemical_list: D019476:Insect Proteins; D007306:Insecticides