556 TRYPANOSOMIASIS 



lethargy has been recognised as prevailing on the West Coast of 

 Africa from the Senegal to Lagos and in the parts lying behind 

 the coast between these regions. It has also been found to be 

 rife from Cameroon to Angola and in the Congo valley, and to a 

 less extent up the Niger and its tributaries. In 1901 it began 

 to appear in the Uganda Protectorate, and it is in that region 

 that the investigations have been carried on which have led 

 to a knowledge of its cause ; here it has wrought very serious 

 havoc amongst the native population. It is characterised 

 in the early stages by a change in disposition leading to 

 moroseness, apathy, disinclination for work or exertion, and 

 slowness of speech and gait. There may be headache, indefinite 

 pains about the body, the evening temperature may be elevated 

 several degrees, the pulse tends to be soft and rapid, and in a 

 very large number of cases the superficial glands of the body are 

 enlarged. In a rapid case the lethargy becomes more pronounced ; 

 fine tremors, especially of the tongue and arms, develop ; pro- 

 gressive emaciation occurs blood changes appear, consisting of a 

 progressive diminution of the red cells and of the haemoglobin, 

 and of a lymphocytosis in which the percentage of both the 

 large and small mononuclear cells is increased, so that the former 

 may constitute from 20 to 30 and the latter from 30 to 40 per 

 cent of all the white cells present. As the disease progresses 

 the drowsiness increases till it deepens into a coma from which 

 the individual cannot be roused. Often during the disease there 

 occur irregular cedematous patches on the skin and sometimes 

 erythematous eruptions, and effusions into the serous cavities. 

 Not every case runs a progressively advancing course. Some- 

 times along with enlargement of glands the chief early feature 

 is the occurrence from time to time of attacks of fever which 

 may be mistaken for malaria, and from these apparently coin- 

 plete recovery may take place; recurrence, however, follows 

 as a rule, and ultimately the typical terminal phenomena 

 may commence. Such cases may go on for years, and it is 

 probable that many patients die of pneumonia without exhibiting 

 typical manifestations of the malady from which they really 

 suffer. The disease is an extremely fatal condition, and probably 

 no case where the actual lethargy is developed ever recovers. 



On considering the disease from the standpoint of patho- 

 logical anatomy there is little to be said. As Mott described, 

 the most striking feature is the presence of a chronic meningo- 

 encephalitis and meningo-myelitis. The pia-arachnoid is some- 

 times opaque and slightly thickened and may be adherent 

 to the brain, and its vessels usually show some congestion. 



