Research into the trypanosomiasis problem : a critical consideration of suggested measures : with discussion and report of the Glossina Sub-Committee / by Warrington Yorke.

  • Yorke, Warrington, 1883-1943.
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.

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    to commit the indiscretion) that the Colonial Office would be well advised to co-ordinate the work of its various bodies and committees like the Tropical Diseases Research Fund, Tropical Diseases Bureau, and the Imperial Bureau of Entomology by appointing a Tropical Research Council on lines similar to the admirable Medical Research Council which has recently been formed for the co-ordination of research work under Govern¬ ment auspices in this country. Increased support from the Treasury might be forthcoming if a close link were established with this Council. It would be the duty of the Tropical Research Council to enquire into the needs and to delimit the activities of the various bodies receiving Government aid. Colonel D. Harvey : I would like to make a few remarks on the discussion, but I have no intention of entering into the controversy. Professor Yorke, in his paper, referred to the fact that he had found 16 per cent, of the game in the district where they were working, the Luangwa Valley, were infected with trypanosomiasis, with the organism pathogenic to man, and he said that Commission, of which I was a member, confirmed this fact. That is hardly how we should have expressed it. I am giving my own ideas, as Sir David Bruce is, unfortunately, away from England. If Professor Yorke had said we found that the trypanosome that was present in cases of human trypanosomiasis in our district of Nyasaland was identical with the trypanosome which we found in game, I should have been at one with him. But when he says this trypanosome which they and we found was pathogenic to man, that was just the bit of evidence that was wanting. We spent three years trying very hard to identify as one or separate these two trypanosomes, but at the end of that time we had to confess we had not done so. The trypanosomes of game and those in man were the same morphologically in their action on experimental animals and their development in the fly, yet we could not say that the game trypanosome was pathogenic to man. Taute came to our camp, and stayed a fortnight, and we said to him, “All that remains now is to find out whether this game trypanosome is pathogenic to man.” He said, “ I am convinced it is not,” and he added, “ I am willing to demonstrate it on myself.” We said, “Very well, we have a nice strain of game trypanosome here.” He replied, “ I will not do it here ; you have the human trypanosome in your district; I will go to the other side of the lake, where there is no human sickness, and I will carry out the experiment there.” He went off, and shortly afterwards we received a letter from him, giving full details of the experiment on himself, shewing that he, at least, had not been infected either by the fly or the inoculation of the blood of infected animals. We said that this shewed only that Taute himself was immune to this particular trypanosome. Therefore, that point had not been settled. The only other thing we could see that remained to be done was to work out carefully the epidemiology, that is, to find out whether this disease was widespread wherever the game was to be found. We had to leave the question like that because we could not say more. Sir David Bruce stated in the report, “ It will be found difficult, or even impossible, to arrive at a certain decision with regard to identifying these two strains.” The only fresh evidence which Professor Yorke tells us about are these further experiments of Taute’s, and Professor Yorke says he does not think this carries us much further. But I think it carries us to this point, that the strain of trypanosome which Taute was working on was not pathogenic to man. The only other piece of evidence which has come along since is the epidemiological evidence which was afforded during the war, and which Dr. Bagshawe referred to. We have had interesting reports about that. Not only German but our own troops—South African and British—went through German East Africa, and it was only in certain parts— although morsitans is widely spread all over the country—that a few men were affected with the Rhodesian sickness. These regions were known before as the parts where this sickness was to be found, and it was when the troops got down near the Rovuma River, and one main road in Portuguese East Africa, that one or two men were infected. When the men went to a certain part of this road, half a dozen of them contracted rhodesiense sickness. This evidence, therefore, favours the view that the human Rhodesian trypano¬ some is a different strain, though a similar trypanosome.