Insecticide resistance in Aedes aegypti across sub‐Saharan Africa: An overview and perspectives for effective arbovirus control

Abstract

Arboviruses transmitted by Aedes aegypti and Aedes albopictus , including Zika, yellow fever and especially dengue and chikungunya, represent a growing public health concern in Africa. Insecticide‐based strategies remain essential for the prevention and control of arboviral outbreaks. However, insecticide resistance in Ae. aegypti is globally widespread and appears to be rising in sub‐Saharan Africa. Here, we reviewed the distribution and phenotypic and molecular evidence of insecticide resistance in Ae. aegypti across sub‐Saharan Africa and summarized the underlying resistance mechanisms and key knowledge gaps. Bibliographic databases were searched for studies published between January 2010 and December 2023. The review identified 40 studies from 18 of 47 countries in sub‐Saharan Africa. Among adults mosquitoes, resistance to dichlorodiphenyltrichloroethane (DDT) and pyrethroids was reported in multiple studies across West and Central Africa, while resistance to carbamates was also documented in several countries, comparatively fewer studies reported resistance to organophosphates. For larvae 7 of 40 studies assessed susceptibility to temephos, with potential resistance reported in only one study. Molecular investigations identified five kdr mutations including F1534C, V1016I, V410L, V1016G and S989P in 12 countries while metabolic resistance involving cytochrome P450s, carboxylesterases, glutathione S‐transferases and other detoxification enzymes was reported in a smaller number of studies and countries. Overall, the evidence base remains geographically uneven and limited for several insecticide classes and resistance mechanisms. This review highlights important knowledge gaps, including the limited assessment of larvicides, emerging adulticide options, resistance intensity and Aedes‐targeted vector control interventions, and underscores the need for more systematic and standardized insecticide resistance surveillance across sub‐Saharan Africa.