Word: ddt
(lookup in dictionary)
(lookup stats)
Dates: during 1970-1979
Sort By: most recent first
(reverse)
Resistant mosquitoes are defying DDT and infecting millions
...malaria. As recently as 15 years ago, health authorities were confident that they were well on the way to the total conquest of malaria. The dread disease, which afflicted as many as 300 million people at a time in the 1940s, was being swept away by the clouds of DDT spray that killed the malaria-transmitting Anopheles mosquitoes. Now, in Asia, Africa and Latin America, malaria is again on the rampage; the number of cases around the world has risen to an estimated 120 million...
...financing a massive extermination operation. In hundreds of yellow-painted Jeeps and trucks equipped with tanks of insecticides, crews traveled everywhere, spraying pools of stagnant water, obvious breeding areas for mosquitoes. Helmeted personnel entered millions of houses and shacks to spray the walls, on the rationale that the oily DDT residue would knock out any disease-carrying mosquito that alighted there.* The campaign succeeded so well that malaria was reduced in many countries to a minor public-health problem. Similar success was achieved under World Health Organization auspices in Asia and parts-but by no means all-of Africa...
...then, lulled into a false sense of security and hindered by oil price hikes, many governments cut back on their eradication programs. At the same time, Anopheles mosquitoes became increasingly resistant to DDT. As the mosquitoes swarmed, malaria made its maleficent comeback...
...effort to stem the tide of new cases, health authorities are now using more of other insecticides, such as Malathion and propoxur to kill DDT-resistant mosquitoes-but the insects are already showing signs of developing resistance to the newer chemicals. Thus the most practical response now to malaria's new challenge, says Dr. Robert Kaiser, of the Center for Disease Control in Atlanta, is a return to the pre-DDT approaches: draining mosquito-breeding areas and monitoring water supplies. In addition, several drugs can be used both to prevent and to treat human malarial infections. Says Kaiser...