AFRICAN TRYPANOSOMIASIS 147 



In searching for trypanosomes, the following methods are avail- 

 able : — 



(i) The peripheral blood, fresh blood films. Stained blood better 

 for details of parasite, but less frequently successful. 



(2) Scarification of the epidermis. Examine resulting lymph for 

 the trypanosomes. Not very successful. 



(3) Citrated blood, centrifuged repeatedly. Examine the third sedi- 

 ment. The results are better. 



(4) Centrifuge citrated blood in small tubes and examine the leuco- 

 cytic layer. Button and Todd's method. 



(5) Puncture the glands and examine the juice. The glands are 

 often small and natives object to the puncture. A valuable method. 



(6) Centrifuge cerebro-spinal fluid for 15 minutes, examine sediment 

 fresh and stained. It is negative in febrile but positive in sleeping 

 sickness stage. A valuable method, introduced by Castellani. 



(7) Inoculate susceptible animals. Use 20 c.c. of blood or cerebro- 

 spinal fluid and inject it into monkeys or guinea-pigs, dogs or white 

 rats. Monkeys and white rats are soonest killed in positive cases. 

 See p. 132. 



PROGNOSIS. 



It is always serious. 



It is curable in the febrile stage but not in the sleeping sickness 

 stage. All Rhodesian cases, febrile and later stages have remained 

 uncured hitherto. There is one queried case of recovery diagnosed in 

 May, 1913. Of 500 trypanosome cases invalided to England, 300 are 

 already dead. 



Improvement is always possible except near the end. 



With treatment, life is prolonged; without it death is almost certain. 



The Congo gambiense strain of trypanosome is the least virulent. 



The Uganda gambiense strain of trypanosome is the more virulent. 



The Rhodesian gambiense strain of trypanosome is the most viru- 

 lent. 



Death is inevitable in the sleeping sickness stage. 



Whole villages have been depopulated by it in Senegambia, Angola, 

 Uganda and the Congo. The populations of the islands of Lake 

 Victoria Nyanza have been annihilated by it. 



TREATMENT. 



Nothing need be said here concerning good hygienic conditions, 

 the exclusion of accompanying diseases, &c. 

 There is no specific for the disease. 

 vSoamin has not realized the hopes of its inventor. 



