HUMAN TRYPANOSOMIASIS 14! 



be reduced, and life much prolonged by its administra- 

 tion. The effects were not permanent ; if the arsenic were 

 pushed the animals died from arsenical poisoning, whilst 

 if given in smaller amounts the trypanosomes became 

 tolerant of the drug and the animals died of trypanoso- 

 miasis. 



In human trypanosomiasis it was soon found that only 

 a few persons could tolerate arsenic given by the mouth 

 in sufficient quantities for the parasites to be affected, 

 and one case so treated is still in good health eleven years 

 after the treatment was commenced. Various forms of 

 injection of the drug were tried, cacodylates and the like, 

 but arsenic in the form of atoxyl or soamin appears to 

 be both the safest and most promising. In the lower 

 animals very large doses seemed to effectively control the 

 disease without producing arsenical poisoning. In man 

 smaller doses have to be used or arsenical poisoning will 

 result. The most successful method is to use a freshly 

 made 10 per cent, solution of atoxyl in normal saline. 

 The solution must be sterilized before use and injected 

 whilst still warm into one of the large muscles, such as 

 the gluteus maximus : 20 irt every alternate day can 

 always be borne, and the dose should be gradually in- 

 creased and given more frequently till a decided effect is 

 produced, 2\ to 3 gr. of atoxyl will usually suffice 

 for each dose ; in some persons symptoms of poisoning 

 are produced by 25 in, but a larger dose is better 

 and in most cases can be taken. In some 70 -\\\ or 

 more may be well borne ; 30 n| every other day 

 appears to be an effective dose, the parasites diminish 

 in number and ultimately cannot be found. The glands 

 become small and hard, the temperature normal, and the 

 eruption ceases to appear. The general health also is 

 completely restored. Relapses occur, particularly if there 

 be any intercurrent disease. The atoxyl treatment should 

 be continued for at least two years after the symptoms 

 have disappeared. Sufficient time has not yet elapsed for 

 certainty as to the completeness and permanency of the 



