In those children who survive, malaria also drains vital nutrients from them, impairing their physical and intellectual development. Malarial sickness is also one of the principal reasons for poor school attendance. Yet protection of children can often be easy. Randomised control trials conducted in the Gambia, Ghana, Kenya and Burkina Faso, for example, show that about 30 per cent of child deaths could be avoided if children slept under bednets regularly treated with recommended insecticides such as pyrethroids. Unlike early insecticides such as DDT, pyrethroids are derived from a naturally occurring substance, and will remain effective for 6 to 12 months.
Malaria is also particularly dangerous during pregnancy.
It causes severe anaemia, and is a major factor contributing to maternal deaths in malaria endemic regions. Pregnant mothers who have malaria and are HIV-positive are more likely to pass on their HIV status to their unborn child. The estimated costs of malaria, in terms of strains on the health systems and economic activity lost, are enormous. In affected countries, as many as 3 in 10 hospital beds are occupied by victims of malaria. In Africa, where malaria reaches a peak at harvest time and hits young adults especially hard, a single bout of the disease costs an estimated equivalent of 10 working days.