True, there are other variables in affect, poor sanitation, climate variation, poverty, imprudent human practices involving pollution (discarded tires, bottles, dams), warfare, etc. I was simply trying to point out that DDT is not the cure all solution. Looking back, even if the DDT eradication program had success in some areas it failed miserably to reduce the overall number of malaria cases. It should be a multilevel approach.
But the one thing I must give gungasnake credit for bringing up is the fear behind this compound. In malaria ridden countries, DDT used sparingly to spray houses is not that dangerous to the environment as overuse in the sense of large scale agricultural spraying. Recently, around 2007, in sub-Saharan Africa, there have been instances of inside wall being coated with DDT.
The irony of the controversy around this compound is that some parts of developed countries eradicated malaria using DDT.