The strategy to fight malaria in Africa includes antimalarial drugs and several other initiatives to prevent the mosquito from infecting people. The use of insecticide treated bednets and indoor spraying have been the most widely used.
These are all targeted at the malaria vector, the mosquito. But there are two challenges.
Firstly, mosquitoes have adopted survival tactics, changing their human biting behaviour and developing resistance to insecticides such as DDT and pyrethroid.
Before the widespread use of treated bednets, only 5% of mosquitoes were biting humans between 6pm and 9pm before people went to bed. Since bednets have been introduced, up to 15% of mosquitoes bite people before they go to bed, increasing the risk of infection.
Mosquitoes have also started to avoid resting on insecticide treated surfaces inside houses and instead bite and flee the house.
The second challenge is climate change which has resulted in mosquitoes breeding faster and the disease, in turn, spreading faster. Malaria is now present in areas that were previously not marked as transmission zones.
A third challenge faced in the urban environment is the lack of well managed drainage systems that would discourage mosquito breeding.