In this study, we analysed observations of resistance levels in some of the most important malaria vector species sampled from 1183 locations spanning 38 African countries. If mosquitoes show cross-resistance to multiple insecticide types, then the number of insecticides that remain effective is limited. Therefore, our research looked for evidence of common patterns of resistance amongst the different types of insecticides that are most important in mosquito control programs.
We found strong relationships in resistance to three commonly used pyrethroids, which were also linked to resistance to DDT. These relationships were consistent across a large part of sub-Saharan Africa. We also found links between patterns of resistance and genetic variation across wild mosquito populations. These results can guide the design of resistance management strategies, and they also highlight the need for the development of novel insecticides.