title: Impact of Insecticide Resistance on the Effectiveness of Pyrethroid-Based Malaria Vectors Control Tools in Benin: Decreased Toxicity and Repellent Effect.
abstract: Since the first evidence of pyrethroids resistance in 1999 in Benin, mutations have rapidly increased in mosquitoes and it is now difficult to design a study including a control area where malaria vectors are fully susceptible. Few studies have assessed the after effect of resistance on the success of pyrethroid based prevention methods in mosquito populations. We therefore assessed the impact of resistance on the effectiveness of pyrethroids based indoor residual spraying (IRS) in semi-field conditions and long lasting insecticidal nets (LLINs) in laboratory conditions. The results observed showed low repulsion and low toxicity of pyrethroids compounds in the test populations. The toxicity of pyrethroids used in IRS was significantly low with An. gambiae s.l (< 46%) but high for other predominant species such as Mansonia africana (93% to 97%). There were significant differences in terms of the repellent effect expressed as exophily and deterrence compared to the untreated huts (P<0.001). Furthermore, mortality was 23.71% for OlyseNet® and 39.06% for PermaNet®. However, with laboratory susceptible "Kisumu", mortality was 100% for both nets suggesting a resistance within the wild mosquito populations. Thus treatment with pyrethroids at World Health Organization recommended dose will not be effective at reducing malaria in the coming years. Therefore it is necessary to study how insecticide resistance decreases the efficacy of particular pyrethroids used in pyrethroid-based vector control so that a targeted approach can be adopted.
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
authors.forename: Fiacre R
authors.initials: FR
authors.lastname: Agossa
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
authors.forename: Virgile
authors.initials: V
authors.lastname: Gnanguenon
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
authors.forename: Rodrigue
authors.initials: R
authors.lastname: Anagonou
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
authors.forename: Roseric
authors.initials: R
authors.lastname: Azondekon
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
authors.forename: Nazaire
authors.initials: N
authors.lastname: Aïzoun
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
authors.forename: Arthur
authors.initials: A
authors.lastname: Sovi
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Oké-Agbo
authors.affiliation: Laboratoire Evolution, Biodiversité des Arthropodes et Assainissement, FAST-UAC, Abomey-Calavi, Bénin.
authors.forename: Michel
authors.initials: M
authors.lastname: Sèzonlin
authors.affiliation: Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.|Laboratoire Evolution, Biodiversité des Arthropodes et Assainissement, FAST-UAC, Abomey-Calavi, Bénin.
authors.forename: Martin C
authors.initials: MC
authors.lastname: Akogbéto
mesh_terms: D000818:Animals; D000852:Anopheles / Q000187:drug effects* / Q000235:genetics; D001541:Benin; D005260:Female; D007302:Insect Repellents / Q000008:administration & dosage / Q000633:toxicity*; D007305:Insecticide Resistance; D057148:Insecticide-Treated Bednets; D008288:Malaria / Q000517:prevention & control* / Q000635:transmission; D011722:Pyrethrins / Q000008:administration & dosage / Q000633:toxicity*
chemical_list: D007302:Insect Repellents; D011722:Pyrethrins