Kofi Akosah in Accra, Ghana, writes in the latest Campaign for Fighting Diseases newsletter about the prospects for the use of DDT in fighting malaria in his home country. He first describes the devastation that the disease wreaks: “More than 17 million of Ghana’s 20 million people are infected by malaria every year, costing the nation a colossal 850 million cedis (US$94 million) for treatment alone.”
He continues, “Those infected by malaria are in and out of hospital and unable to work. Malaria takes an especially heavy toll on farmers. Swarms of mosquitoes make it impossible for farmers and their families to sleep indoors especially, during the rainy seasons when they are forced to sleep outdoors around bonfires.”
Akosah blames in large part the regulations and methods used by the World Health Organization, which he says have “advocated the use of insecticide-treated bednets in vector control, almost to the exclusion of other proven measures.” One such measure that the WHO has decided to reintroduce in limited use, is “Indoor Residual Spraying, which involves spraying the interior walls of dwellings with a small amount of DDT. This acts as an irritant to the mosquitoes, which prevents them from coming in the house in the first place. Those that do make it inside are quickly repelled outside.”
One of the reasons that DDT had been excluded from WHO treatments against malaria was the havoc that the use of the chemical caused nearly fifty years ago. As Chuck Colson writes, the WHO “sprayed the people’s thatch-roofed huts with DDT—and set in motion a life-and-death illustration of the importance of respecting the natural order.”
He says that the unintended consequences of the application of DDT to the huts followed after the mosquitos had been killed: “The pesticide killed the mosquitoes, but it also killed a parasitic wasp that kept thatch-eating caterpillars under control. The result? People’s roofs began caving in.”
“And then things really got bad,” Colson continues. “The local geckos feasted on the toxic mosquitoes—and got sick. Cats gorged on sick geckos—and dropped dead. And then, with no cats, the rats began running wild, threatening the people with deadly bubonic plague.” All this points to the dangers of the unintended consequences of any policy initiative, but especially one that involves the alteration of the natural environment.
The way to deal with the reality Colson describes, however, is not necessarily to abandon the use of DDT altogether, but to learn from the mistakes of the past. This is why current advocates of the use of DDT emphasize that it is indoor spraying that is the legitimate use of the chemical.
The statement of the Kill Malarial Mosquitos NOW! coalition (PDF) states vehemently that it is in favor “only for indoor residual spraying (which results in zero-to-negligible external environmental residue) – and not for aerial or any other form of outdoor application.”
For more on the coalition, see this entry from the PowerBlog, “Add DDT to the Malaria-Fighting Arsenal.”