DDT for malaria control: the issue of trade.
In September, 2006, WHO recommended wider use of indoor spraying with dichlorodiphenyltrichloro ethane (DDT)--once banned because of its toxic effects on the environment--and other insecticides to control malaria. Since then, a number of African countries have made their old foe DDT their new friend. Malawi is the latest, announcing last week that it would be introducing indoor residual spraying with DDT in its fight against malaria. WHO cited many reasons for making DDT a main intervention in malaria control, alongside insecticide-treated bednets. DDT has the potential to substantially reduce malaria transmission. The chemical is better than other insecticides, as it lasts longer, thereby reducing the number of times that houses need to be sprayed, is cheaper, and can repel mosquitoes from indoor environments, as well as kill those that land on sprayed surfaces. But DDT is far from problem-free. WHO, and countries that decide to adopt indoor residual spraying with the insecticide, need to monitor any negative effects of the chemical on health. They also need to ensure that DDT does not contaminate crops. (excerpt)