Insecticide susceptibility of <it>Aedes aegypti</it> populations from Senegal and Cape Verde Archipelago

<p>Abstract</p> <p>Background</p> <p>Two concomitant dengue 3 (DEN-3) epidemics occurred in Cape Verde Archipelago and Senegal between September and October 2009. <it>Aedes aegypti</it> was identified as the vector of these epidemics as several DEN-3 virus strains were isolated from this species in both countries. The susceptibility to pyrethroids, organochlorine, organophosphates and carbamate was investigated in two field strains of <it>Aedes aegypti</it> from both countries using WHO diagnostic bioassay kits in order to monitor their the current status of insecticide susceptibility.</p> <p>Findings</p> <p>The two tested strains were highly resistant to DDT. The Cape Verde strain was found to be susceptible to all others tested insecticides except for propoxur 0.1%, which needs further investigation. The Dakar strain was susceptible to fenitrothion 1% and permethrin 0.75%, but displayed reduced susceptibility to deltamethrin, lambda-cyhalothrin and propoxur.</p> <p>Conclusions</p> <p>As base-line results, our observations stress a careful management of insecticide use for the control of <it>Ae. aegypti</it>. Indeed, they indicate that DDT is no longer efficient for the control of <it>Ae</it>. <it>aegypti</it> populations in Cape Verde and Dakar and further suggest a thorough follow-up of propoxur susceptibility status in both sites and that of deltamethrin and lambda-cyhalothrin in <it>Ae. aegypti</it> populations in Dakar. Thus, regular monitoring of susceptibility is greatly needed as well as the knowing if this observed resistance/susceptibility is focal or not and for observed resistance, the use of biochemical methods is needed with detailed comparison of resistance levels over a large geographic area.</p> <p>Keywords</p> <p><it>Aedes aegypti</it>, Insecticides, Susceptibility, Cape Verde, Senegal</p