The paradox of the effectiveness of IRS insecticides (including DDT) and its impacts on human health - what can we fix if it isn’t broken?

Abstract

The effectiveness of DDT and other insecticides when properly used as indoor residual spray (IRS) to combat malaria is not in question [1]. However, the high body burden of DDT of those protected is very high [2], and the human health consequences due to IRS insecticides of those protected are of great concern [1-3]. What may be questioned though are the effectiveness, health impacts, social consequences, and sustainability of some IRS alternatives. Many promising ‘silver bullets’ (using anything but IRS) to beat malaria over the last number of decades have come and gone. Yet, the one proven method, IRS, gets less recognition or attention. IRS interrupts transmission where most infections occur - the home. It is also at home where those most likely to suffer malaria - babies, children and pregnant mothers - are to be found. The negative part of the IRS message though, remains the inevitable co-exposure of the very same susceptible groups to IRS insecticides. Protection by IRS comes at a cost, creating a paradox -protection from deadly malaria may carry a health burden due to the IRS chemicals used [1,3].