Annual report of the Department of Public Health / Union of South Africa.

  • South Africa. Department of Health
Date:
[1930]
Catalogue details

Licence: Public Domain Mark

Credit: Annual report of the Department of Public Health / Union of South Africa. Source: Wellcome Collection.

    68/80 page 66
    m ANNEXURE “ B.” The Honourable the Minister of Public Health, Union Government of South Africa, Union Buildings, Pretoria. Sir, I have the honour to forward herewith some observations on what I have seen during my visit to the Union. In order that my conclusions may he understood, I submit as the first part of these memoranda, a copy of the conclusions that I reached during my investigations in Malaya. | These conclusions were published on pages 361-366 of my “ Prevention of Malaria in the Federated Malay States ” (1920).] Mosquito Reduction. 1. From a malarial standpoint, the Malay Peninsula can be divided into several zones which may conveniently be distinguished as, the Mangrove Zone, the coastal plain, the coastal hills, the inland plain, and the inland hills. 2. These zones may be malarial naturally, or may become so through the operations of man. 3. The part of the Mangrove Zone covered daily by the tide contains no anopheles and is non-malarial. When the forest is felled and the tidal flow obstructed, it may become intensely malarial from the appearance of A. ludlowi, which has been proved to be a natural carrier of malaria, and is probably the most important carrier in the Mangrove Zone. 4- The part of the Mangrove Zone covered only by the spring tides is naturally malarial from the presence of A. umbrosus, which has been proved to be a natural carrier of malaria. Clearing the forest allows A. ludlowi to enter this portion of the zone also. 5. Both A. ludlowi and A. umbrosus are eliminated by clean weeded drains and good drainage and many examples of how good agriculture abolished these mosquitoes and their malaria from the Mangrove Zone can be given. 6. The coastal plain is malarial from the presence of A. umbrosus in its virgin jungle. T. Hundreds of square miles of flat land in the coastal plain of Malaya have been freed from malaria by simply draining and felling the jungle, and cultivating the land. 8. The disappearance of malaria from the coastal plain coincides with the disappearance of A. umbrosus, which breeds in pools in undrained jungle, but cannot breed in open drains when kept free from weeds, and with a current of water. There are probably other reasons connected with the quality of the water in well-drained land. 9. Ten years ago the cost of these rural anti-malarial measures in Malaya was about £3 sterling an acre, being £2 to drain, and £1 to fell the heavy virgin jungle. This expenditure is, at the same time, the first step in agriculture, and the land has then acquired a considerably increased value. To-day the cost of draining and felling is about 70 per cent, higher. When an estate is newly opened, it is possible for the medical officer to select non-malarial sites, and the cost of controlling malaria is, of course—nil. 10. In the low coastal hills next to the coastal plain, malaria is preva¬ lent when the ravines are under jungle owing to the presence of A. umbrosus in large numbers. 11. Clearing and draining of these ravines free them from A. umbrosus, but does not free the land from malaria. 12. Malaria persists in the coastal hills after the ravines have been cleared and drained and after A. umbrosus has disappeared, from the appear¬ ance of A. maculatus. 13. A. maculatus does not live in ravines covered by heavy jungle but appears only after the shade has been removed- The cleaner the water, and the better drained the ravine, the more suitable the ravine becomes for A. maculatus.
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