i 



CHAPTER X. 

 HUMAN TRYPANOSOMIASIS. 



(SLEEPING SICKNESS.) 



DISEASES due to the presence in the blood of trypano- 

 somes. The best known the African forms manifest 

 themselves as long-continued fevers, at first of a severe 

 type, but later low forms of hectic fever, or periodic 

 attacks of fever, and associated with enlargement of the 

 lymphatic glands, especially the cervical ; evanescent 

 rashes, and often splenic enlargement. They usually 

 terminate fatally with cerebral symptoms, those of the 

 form long known as sleeping sickness being the most usual, 

 or death occurs earlier from intercurrent diseases or from 

 cardiac failure. 



Geographical Distribution of Sleeping Sickness. The 

 disease is only known in Tropical Africa as an indigenous 

 disease, but many cases have been reported in Europe, all 

 in persons who had resided in Africa within the last few 

 years. As judged by the distribution of its terminal phase 

 sleeping sickness the disease has within recent years 

 been spreading rapidly across Africa. There are differ- 

 ences in the parasites in Rhodesia from those in Uganda 

 and the Congo, and the former is the more severe type, but, 

 clinically, they resemble each other and are considered 

 here together. It was unknown on the Zambesi and 

 south of it till recently, and is now known in the 

 neighbourhood of Lake Nyasa, and to the west of this 

 lake. It is prevalent throughout the Congo, but is rare 

 on the Gold Coast, in Lagos, and in Southern Nigeria. 

 It has been introduced into the neighbourhood of Vic- 

 toria Nyanza within the last twenty years, and now 

 extends throughout that district and down the Nile some 



