By Jessie Stone, a medical doctor, is the founder and director of Soft Power Health, a nonprofit organization in Uganda (THE NEW YORK TIMES, 22/09/06):
TO many of us in the malaria-control business, it came as no great surprise last week when the World Health Organization recommended wider use of DDT in Africa to combat the mosquitoes that cause the disease, which kills more than a million people a year, most of them children in Africa.
The W.H.O.’s endorsement of DDT for spraying inside houses has the support of Congress and the Bush administration. With the W.H.O.’s encouragement, several African nations have approved DDT for use in indoor residual spraying (that is, spraying the walls of huts to kill the mosquitoes that wait there until dark). Uganda’s Ministry of Health and National Malaria Control Program, for example, have embraced this approach. Newspaper articles across Africa have assured readers that DDT has gotten a bad rap and is, in fact, safe for use.
But people have short memories. Doesn’t anyone remember the American bald eagle? DDT brought it to the brink of extinction. In part because of that, the use of DDT was banned in 1972. (The Department of Health and Human Services, the International Agency for Research on Cancer and the Environmental Protection Agency have all listed DDT and its breakdown products, DDE and DDD, as possible carcinogens.) DDT is a persistent organic compound and can remain in the environment long after its initial use, entering the food chain and accumulating in fatty tissue. Even when the United States instituted spraying in 2000 to kill the mosquitoes that carry West Nile virus, it didn’t use DDT.
Although DDT helped eliminate malarial mosquitoes in South Africa, the case was unique — that type of malaria was directly related to the length and intensity of the rainy season, when malarial mosquitoes are active — and we still don’t know the broader impact of its use there. In the African countries where the burden of malaria is greatest, the disease is endemic. Uganda, where it rains throughout the year, could not be more different from South Africa in terms of malaria, and it is a mistake to apply the same formula here. The use of DDT for indoor residual spraying will not produce the same results and will almost certainly have dire consequences.
And spraying is costly. This year in Kabale, in southwestern Uganda, 100,000 huts were sprayed as part of an indoor spraying project. A permethrin derivative, not DDT, was used and the spraying was controlled and safe. The cost was close to $2 million.
Uganda has a population of 28 million, with 7 people on average to a hut. Any comprehensive, nationwide spraying effort would have to reach some four million huts, costing more than $80 million, and that’s only for the first of several rounds of spraying. With Uganda’s resources already overburdened, it makes little sense to embrace an approach that is exceedingly costly from fiscal, human and environmental standpoints.
In Uganda, where I run a malaria education, prevention and treatment program, the most effective weapon against the disease is basic education about how people contract it and how they can protect themselves.
For instance, insecticide-treated bed nets can reduce the incidence of malaria by at least 50 percent and perhaps as much as 90 percent. Combination-drug therapy along with targeted non-DDT spraying inside huts will also be effective in controlling malaria.
DDT is not the magic bullet that will eradicate malaria. We need to refocus resources and attention on something most Africans do not have: basic malaria education, and prevention with insecticide-treated bed nets. A mosquito net costs $6.50 and can last up to five years. An average of three people can sleep under it, and the only harmful effect we have heard about, after having distributed 11,000 nets in the Kamuli, Jinja and Kayung districts over the last two years, is people being hot at night.
We do not have to reinvent the wheel here. We just have to help educate people — even those with the best intentions.