Research into the trypanosomiasis problem : a critical consideration of suggested measures : with discussion and report of the Glossina Sub-Committee / by Warrington Yorke.
- Warrington Yorke
- Date:
- [1920]
Licence: Public Domain Mark
Credit: Research into the trypanosomiasis problem : a critical consideration of suggested measures : with discussion and report of the Glossina Sub-Committee / by Warrington Yorke. Source: Wellcome Collection.
19/30 page 47
![transmission by G. palpalis, one would think there must have been a few cases of mechanical transmission through the agency of other biting flies which occur far from the lake, but this never occurred. A better instance is afforded by the conditions in Principe and S. Thome, which have been already referred to. In Principe, some years ago, sleeping sickness was rife, whereas in S. Thome, a few miles away, not a single indigenous case could be found by the Portu¬ guese investigators, though many infected persons had been imported from Angola. Both islands had abundance of biting insects. The only difference was that S. Thome had no tsetse-flies. Dr. G. C. Low: We have had both sides of the question—the entomological and the medical—discussed to-night, and it is Evident that there is still a great amount of doubt and uncertainty as to many of the points concerned. We have heard that the French authorities propose to treat with atoxyl all infected natives in their areas, so as to destroy the trypanosomes in their blood ; but will this be successful if antelopes and other game are reservoirs of infection? Can entomologists alone settle this very important point ? Dr. Guy Marshall : No. Dr. G. C. Low : Well, that is the whole thing; for settling this and other equally important questions a combination of medical specialists, protozoologists and entomologists is required, and not one of these branches alone. As regards Rhodesian trypanosomiasis, white people infected die with great rapidity, and some natives do so also. It is, however, possible that the disease may last longer in the latter in certain instances, and only large numbers of blood examinations can settle this. To me it looks far more likely that man gets his infection from the game, because human cases are few and far between. Again we await a definite solution of this, and until we get it money will be thrown away. The talk of destroying the whole of the game of Africa is generally indulged in by people who have never being in that country. I would suggest to such enthusiasts that they first try to destroy the rats in a small farm at home before airing their views as to destroying the fauna of a whole continent. The only way an experiment of destroying antelopes and the larger game can be carried out is to enclose a large area with fencing so as to prevent other animals from getting in, but, even then, how'’ can one be ceitain that small rodents, pigs, and animals of that sort are not present ? The fly might even take to feeding on birds in lieu of game. All these matters require careful consideration before any large scheme and spending of public money takes place. I heartily agree with Professoi Yorke s suggestion that this Society should have a say in such matters. We have in it men who know the subject from every standpoint, and a discussion such as we are having now shews how useful and valuable such knowledge is. . _ . „ . There cire m<iny other points I should like to rctise but tune presses. I shall limit myself to only one more question. If we destroy these special areas on the shoies of the Victoria Nyanza, mentioned by Dr. Marshall, what proof have we that the G. palpalis will not adapt itself to other areas ? If anopheline breeding-grounds are destroyed, we know the insects will lay their eggs on water in barrels and other sites never selected under natural conditions, and the same may hold good for tsetse-flies in depositing their eggs in special soils under special conditions. The habits of G. palpalis, as Dr. Marshall has already mentioned, are much different on the West Coast of Africa than in Uganda, approximating more to those of G. niorsitans. Here, again, we have another important point requiring solution. I would suggest that for further work on the subject there should be a happy combination of all experts, and that the research should not be limited to any one individual branch. [Adjourned to Friday, November 19th.]](https://iiif.wellcomecollection.org/image/b31366806_0019.jp2/full/800%2C/0/default.jpg)
