WASHINGTON (Reuters) – Mosquitoes that carry malaria, dengue fever and yellow fever avoid homes that have been sprayed with DDT, researchers reported on Wednesday.
The chemical not only repels the disease-carrying insects physically, but its irritant and toxic properties helps keep them away, the researchers reported in the Public Library of Science journal PLoS ONE.
They estimate that DDT spray reduced the risk of disease transmission by nearly three-quarters.
Malaria affects more 40 percent of the world’s population, killing more than a million people every year, most of them young children.
DDT use has been discontinued in most countries because of fears the pesticide may cause cancer and because of its potential effects on animals such as birds.
But the World Health Organization last year recommended the use of DDT in places like Africa where malaria is still common, saying the benefits outweighed the risks.
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DDT use against malaria was discontinued in some countries because malaria was effectively beaten back. It was discontinued in some countries because the governments fell apart. In several nations where DDT was not a problem, DDT used was discontinued because it kills beneficial insects and animals and poisons humans. It was discontinued in other countries because it ceased being effective. In no country was DDT discontinued due solely to a fear of cancer.