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]
Catalogue details

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.

    18/30 page 46
    the research will involve a large amount of experimental work, which I think it impossible to expect from isolated units of men, no matter who they are, studying in the wilderness of Africa, it is necessary to centralise in a large Commission. Dr. A. G. Bagshawe : As I was another member of the much-criticised Glossina Sub-Commitee, if I were not to say something it might give rise to misconception. In fact, I came with notes, prepared “ to keep my end up,” but Dr. Guv Marshall has done that so excellently for me that I shall refrain from saying anything on that head. He has shewn that this scheme which has been critcised by Dr. Yorke is not a cut-and-dried scheme, but one which can be modified. The method of carrying it out will depend very much on the funds which can be obtained. Professor Yorke would have the work of entomological, medical and veterinary research into the problem of trypanosomiasis combined under one central organisation in Africa. I wonder if the time is suitable for a great investigation of that kind : it would cost a great deal of money, and, if the funds were not ample, the pinch would be felt either by the entomological or pathological side; hitherto it has been the entomological side which has suffered. I doubt if it is practical politics to explore all the links of the chain of the causation of trypanosomiasis on a great scale at once. It is the entomological link which has been least explored, and it is proposed that entomologists should now have their chance. The disease has never been systematically approached from the insect side. I incline to think that the restriction of fly is at least as likely to be realised as is the restriction of game, including under that head such animals as pig. At the moment both seem to be extraordinarily difficult problems. Professor Yorke still believes that the morphologically identical trypanosomes which infect domestic animals and man respectively in East Tropical Africa are identical biologically. But, apart from the results of Taute’s and Huber’s gigantic experiment, there is the epidemiological objection to accepting his view. In the late campaign in East Africa there was no case of trypanosomiasis in man met with among British or German troops north of g° S., though tsetse-fly abounded and draught animals succumbed. It was not until the Germans got to 90 S. that they found human trypanosomiasis. Between that line and the other side of the equator there is a large amount of morsitans, and this trypanosome of game which corresponds morphologically to the human one has been found many times, and it has been found on' the West Coast of Africa too. But no human case of the disease has been found north of the 90 line near the East Coast. Now, to pass to another matter, which has not been touched on to-night. In the report of the French Committee there is a point which Professor Yorke has not men¬ tioned— of course he had not time to mention everything. The French Committee say that in French West Africa epidemics of human trypanosomiasis are due to mosquitoes, which, in their opinion, transmit infection from one member of a family to another, lead¬ ing to the so-called house or family infection. The endemicity is due to the Glossina, but the epidemics in villages are due to transmission by domestic mosquitoes. The Governors of the French Colonies in West Africa, in accordance with this advice, have enacted that all Europeans leaving French Possessions in Africa should be examined for trypanoso¬ miasis, and, in the event of their being infected, that they shall receive an injection of atoxyl before they embark. It seems very sound for their own sakes that such cases should be discovered early, but the reason is lest these persons should infect their cabin companions through the agency of mosquitoes on the voyage home. Infection through the agency of mosquitoes is against British experience. Obviously it might occur, but I know of no record that it has, and this French measure seems to be an ultra-precaution. In the great epidemic in Uganda, though large numbers of natives visited the lake shore beyond the narrow fly-infested zone, and returned to their homes with sleeping sickness, no case of transmission of the disease to a person who had not visited the lake shore was reported or discovered, though in many of the villages concerned mosquitoes must have abounded. This goes against the theory that the spread of sleeping sickness n the great epidemic on the Victoria Nyanza was due to mechanical transmission. If it was due to mechanical
    No text description is available for this image
    No text description is available for this image
    No text description is available for this image