The intersection of Malaria-pesticides-parasites is a classic illustration of the field of gene-environment interactions.
Please read the material in the sub-menus here, and read (and watch) the follow:
1. Short movie (view the third on this web page, but the other two are also relevant):
2. How Malaria Has Affected the Human Genome and What Human
Genetics Can Teach Us about Malaria: Kwiatkowski-1
3. For reference, this is an excellent summary of all human health effects of DDT exposure: Eskenazi et al