Malarial prophylaxis in small isolated communities in central Africa / by R. Howard.

  • Howard, R.
Date:
1908
Catalogue details

Licence: Public Domain Mark

Credit: Malarial prophylaxis in small isolated communities in central Africa / by R. Howard. Source: Wellcome Collection.

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    30 At Malindi the effect has been to quite alter the character of the beach. Below the shelving part is a nearly flat, uneven expanse of sand, and now as the lake level falls each dry season, this is exposed. Here pools suitable for both anophelines and culicines to breed in are of frequent occurrence. They are often stretches of water several yards long, where there is a hollow in the sand, shut off from the lake by an inter- vening ridge. At other times they are pools formed by back eddies, or by the rush of water down the beach during a rainstorm. The reeds have increased in thickness, and drift material mixed with sand is apt to collect among them, and shut off little pools at the edge of the lake, so that fish cannot reach them. All these breeding places are somewhat uncertain, and the waves raised by a storm in the lake may wash most of them away ; but they form again in a few days, and larve, both of anophelines and culicines, can readily be found in them. The season when the condition of the lake shore is at its worst is between June and August; in April, when the lake is at its highest, it still reaches up to the steep beach, and by September it has fallen below the flat part, and the slope of the shore is again steeper, so that few pools form. Little can be done’ in the way a mosquito de- struction. Cutting the reeds is a help, and sometimes if pools are few, they can be filled up; but the greatest difficulty lies in their varying position. In August, after the lake has fallen sufficiently, any remaining hollows can be filled in, and the wet ground planted with vegetables. This has been satisfactorily tried on both sides of the station. It must be recognised, therefore, that so long as the lake level remains low, there will be a considerable number of anophelines breeding on the shore, especi- ally between May and August, and as the European houses are only 50 yards distant, they are within easy reach. On the other hand, fortunately for the health record of Malindi, there is practically segregation of the Europeans. The main native villages are over a mile away on either side, and the steep hill prevents any building behind the station. The key to prophylaxis is the maintenance and im- provement of this isolation. With this object in view more land has been rented on either side of the
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