@article{fdi:010044044,
  title = {{I}nsecticide resistance in {A}nopheles gambiae from south-western {C}had, {C}entral {A}frica},
  author = {{K}erah-{H}inzoumbe, {C}. and {P}eka, {M}. and {N}wane, {P}. and {D}onan-{G}ouni, {I}. and {E}tang, {J}. and {S}ame-{E}kobo, {A}. and {S}imard, {F}r{\'e}d{\'e}ric},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground: {I}ndoor residual spraying and insecticide-treated nets ({ITN}) are essential components of malaria vector control in {A}frica. {P}yrethroids are the only recommended compounds for nets treatment because they are fast-acting insecticides with low mammalian toxicity. {H}owever, there is growing concern that pyrethroid resistance may threaten the sustainability of {ITN} scaling-up programmes. {H}ere, insecticide susceptibility was investigated in {A}nopheles gambiae sensu lato from an area of large scale {ITN} distribution programme in southwestern {C}had. {M}ethods: {S}usceptibility to 4% {DDT}, 0.05% deltamethrin, 0.75% permethrin, 0.1% bendiocarb and 5% malathion was assessed using the {WHO} standard procedures for adult mosquitoes. {T}ests were carried out with two to four days-old, non-engorged female mosquitoes. {T}he {A}n. gambiae {K}isumu strain was used as a reference. {K}nockdown effect was recorded every 5 min and mortality scored 24 h after exposure. {M}osquitoes were identified to species and molecular form by {PCR}-{RFLP} and genotypes at the kdr locus were determined in surviving specimens by {H}ot {O}ligonucleotide {L}igation {A}ssay ({HOLA}). {R}esults: {D}uring this survey, full susceptibility to malathion was recorded in all samples. {R}educed susceptibility to bendiocarb (mortality rate of 96.1%) was found in one sample out of nine assayed. {I}ncreased tolerance to pyrethroids was detected in most samples (8/9) with mortality rates ranging from 70.2 to 96.6% for deltamethrin and from 26.7 to 96.3% for permethrin. {P}yrethroid tolerance was not associated with a significant increase of knock-down times. {A}nopheles arabiensis was the predominant species of the {A}n. gambiae complex in the study area, representing 75 to 100% of the samples. {S}creening for kdr mutations detected the {L}1014{F} mutation in 88.6% ({N} = 35) of surviving {A}n. gambiae sensu stricto {S} form mosquitoes. {A}ll surviving {A}n. arabiensis ({N} = 49) and {M} form {A}n. gambiae s.s. ({N} = 1) carried the susceptible allele. {C}onclusion: {T}his first investigation of malaria vector susceptibility to insecticides in {C}had revealed variable levels of resistance to pyrethroid insecticides (permethrin and deltamethrin) in most {A}n. gambiae s.l. populations. {R}esistance was associated with the {L}1014{F} kdr mutation in the {S} form of {A}n. gambiae s.s.. {A}lternative mechanisms, probably of metabolic origin are involved in {A}n. arabiensis. {T}hese results emphasize the crucial need for insecticide resistance monitoring and in-depth investigation of resistance mechanisms in malaria vectors in {C}had. {T}he impact of reduced susceptibility to pyrethroids on {ITN} efficacy should be further assessed.},
  keywords = {},
  booktitle = {},
  journal = {{M}alaria {J}ournal},
  volume = {7},
  numero = {},
  pages = {art. 192},
  year = {2008},
  DOI = {10.1186/1475-2875-7-192},
  URL = {https://www.documentation.ird.fr/hor/fdi:010044044},
}