Evolution of the and Mutations and Their Potential Impact on the Use of Carbamate and Organophosphates in IRS for Controlling , the Major Malaria Mosquito in Senegal.

Widespread of insecticide resistance amongst the species of the complex continues to threaten vector control in Senegal. In this study, we investigated the presence and evolution of the and resistance genes in natural populations of the main malaria vector in Senegal. Using historical samples collected from ten sentinel health districts, this study focused on three different years (2013, 2017, and 2018) marking the periods of shift between the main public health insecticides families (pyrethroids, carbamates, organophosphates) used in IRS to track back the evolutionary history of the resistance mutations on the and loci. The results revealed the presence of four members of the complex, with the predominance of followed by , , and hybrids. The mutation was only detected in and . hybrids at low frequencies varying between 0.006 and 0.02, while the mutation was found in all the species with a frequency ranging between 0.02 and 0.25. The and genes were highly diversified with twenty-two and thirty-one different haplotypes, respectively. The neutrality tests on each gene indicated a negative Tajima's D, suggesting the abundance of rare alleles. The presence and spread of the and resistance mutations represent a serious threat to of the effectiveness and the sustainability of IRS-based interventions using carbamates or organophosphates to manage the widespread pyrethroids resistance in Senegal. These data are of the highest importance to support the NMCP for evidence-based vector control interventions selection and targeting.