Ddt In The Tropics

ONE of the interesting and most impor tant discoveries of United Nations’ scientists has been in the field of fumigation and insect extermination.

Typhus, dengue, malaria, may eventually be brought under control as a result of the discovery of the insecticide known as DDT. Although on the official secret list until June, 1944, DDT, a white powder in appearance,. has been widely publicised recently, because of the almost miracu lous results in its use against the typhus carrying louse and the malarial mos quito.

The most spectacular experiment was undertaken in January, 1944, when, by fumigating almost the whole city of Naples by dusting every man, woman and child, a serious epidemic of typhus was brought under control, in winter, for the first time in medical history.

Since the Naples epidemic, experiments have x been carried out in many fields, and research is still going on. At this stage, it would not be wise to expect too much of this discovery although, it is past the primary experimental stages, and any experiments which are still being carried out are more in the nature of verification of results obtained elsewhere.

Tests in Fiji last year, proved amongst other things that DDT is an effective and economic medium for destroying mosquito larvae in swampy areas.

Walls, ceilings and furnishings when treated with DDT are unharmed, but for some time after treatment remain fatal to insects such as ants, cockroaches and mosquitoes settling upon them. Sprayed on beds infected with bugs, the pests are exterminated, and the beds remain immune from insects of all kinds for some months. Horses, dogs and cattle, after treatment, repel fly and fleas for a short period, and it appears possible that a solution may be found to the blow fly in sheep and the cattle tick problems in Australia.

DDT appears to have many future uses, particularly in the tropics. It has been used to exterminate caterpillars and other pests, but it is in this field that further

research is necessary. Success has been achieved already by the use of DDT, as an alternative to lead arsenate.

Unpleasant effects may follow if swal lowed, or if much of it is allowed to come into contact with the skin for a pro longed penod, but if handled with ordinary care, DDT has no harmful effects »on man.

At present there is no surplus for general civilian use, heavy supplies are re quired for military purposes, but when restrictions are lifted after the war, it should be of great value in island homes

and in tropical agriculture.-

Pjm.

Editorial Note

THE RAAF is already using DDT insec ticide for aerial spraying of large malarial areas in New Guinea, New Britain and Bougainville. The work is being done from Beaufort bombers, which are equipped with special tanks in their wings.

In the fight against malaria DDT destroys both adult and larval mosqui toes. It is mixed with lighter malariol and emitted in a fine spray over sago swamps and such haunts of the mos quito as are inaccessible from the ground.

Experts are confident that the incidence of both malaria and dengue fever will show a marked decline in the Pacific Islands as a result of this air blitz on mosquitoes.