Mosquitoes' resistance to DDT studied in western Kenya
The study demonstrated that the Anopheles gambiae mosquito has developed a strong resistance to DDT and pyrethroids. The species has also developed a somewhat weaker resistance against carbamates. Fortunately, there is no sign of a resistance against organophosphates.
These results will help researchers and health care workers choose control tools. Now they know that non-pyrethroid-based vector control tools may be more efficient than other prevention methods for malaria in Kenya.
During the last 10 years, there has been a significant increase of insecticide-treated nets (ITNs) and indoor residual spraying (IRS) of various insecticides. These methods are often used in areas that are endemic with malaria around the world. Thanks to these methods, many regions have had a significant decrease in mosquitoes.
Using ITNs and IRS alongside artemisinin combination treatments has decreased the prevalence of malaria and the incidence of the disease. Unfortunately, only some sites have seen a steady, low level of transmission while others show either stable or resurging cases of malaria and vector populations. The researchers attribute this to the growing resistance of the mosquitoes to pyrethroid insecticides.