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Experiments to ascertain if Cattle may act as a Reservoir of the 

 Virus of Sleeping Sichyiess (Trypanosoma gambiense). 



By Colonel Sir David Bruce, C.B., F.E.S., Army Medical Service ; Captains 

 A. E. Hamerton, D.S.O., and H. K. Bateman, Eoyal Army Medical 

 Corps ; and Captain F. P. Mackie, Indian Medical Service. (Sleeping 

 Sickness Commission of the Eoyal Society, 1908 — 10.) 



(Received June 7, — Read June 16, 1910.) 



The question as to whether cattle can act as a reservoir of the virus of 

 Sleeping Sickness is an important one. It was usually helieved until lately 

 that man was the main reservoir, and that the other animals might he 

 ignored. But in view of the fact that the fly on the Lake-shore have 

 remained infective for some two years after the native population have been 

 removed, it is necessary to enquire if it is not possible that other animals may 

 act as well. 



In this regard cattle have been, perhaps, the most important, as on the 

 once thickly-populated Lake-shore and islands they were numerous, and in 

 many cases grazed and watered in the fly-area. Another reason of their 

 importance is, that if they can act as a reservoir, then the same will probably 

 be true of the different species of antelope which inhabit the Lake-shore. It 

 may be presumed that these will greatly increase now that the natives and 

 domestic animals have been removed, and that they will take the place of the 

 cattle in keeping up the infectivity of the Glossiua 'palpalis. 



The Commission, therefore, thought it would be well to enquire into the 

 question, and the result is given in this paper. 



Answers to the following questions were sought : Are cattle capable of 

 being infected with Sleeping Sickness by the sub-cutaneous injection of blood 

 containing Trj/pdnonoma (jumhicim? Can cattle be infected with Sleeping 

 Sickness by tlie bites of artificially-infected tsetse flies ? Can cattle be 

 infected with Sleeping Sickness by the bites of the naturally-infected flies 

 caught on the Lake-shore ? Is it possible to infect tsetse flies by feeding, 

 them on cattle infected with Sleeping Sickness, and afterwards to transmit 

 the disease by means of these IHes to healthy animals !' Finally, if these 

 questions are answered in the allinnative, will it be possible to lind that 

 cattle which liave lived in tlie fly-area are naturally infected with Sleeping. 

 Sickness ? 



