The Blood Flagellates 587 



tions has been noted in the kidney, brain, inner ear, fetal heart, lymph 

 glands, wall of the stomach, and the choroid plexus. Chronic inflamma- 

 tion of the brain is not observed until after the trypanosomes have 

 reached the cerebrospinal fluid. Capillary hemorrhages sometimes occur, 

 and there is a proliferation of neuroglia and endothelial cells, the latter 

 sometimes even in the arteries. Some of the neurons may degenerate 

 and atrophy of dendrities is observed occasionally. The spinal cord is 

 usually affected less severely than the cerebral cortex. 



Rhodesian sleeping sickness is similar in many respects to the Gambian 

 variety but is generally more acute. Fever is more evident in early stages, 

 while early enlargement of lymph glands is less common than in the 

 Gambian variety. Also, the mortality is higher in Rhodesian sleeping 

 sickness, although mild cases supposedly of the Rhodesian type have been 

 reported occasionally. 



Diagnosis. During the acute phase, laboratory diagnosis is compara- 

 tively easy. The trypanosomes can usually be detected in fresh or stained 

 blood films and in material obtained by puncture of enlarged lymph 

 glands. In later stages fewer flagellates are present in the blood, so that 

 examination of several blood films, or preferably thick smears, may be 

 necessary to detect the parasites. Smears from centrifuged blood may be 

 positive when thin films or thick smears are negative. During the sleeping 

 sickness stage, blood examination is much more likely to be negative. 

 Therefore, the examination of cerebrospinal fluid, obtained by lumbar 

 or cisternal puncture, may be necessary if other methods fail. 



Chemotherapy. A number of drugs have been used in treatment of 

 Gambian sleeping sickness, some with fair success and others with good 

 results. In the experience of Kellersberger (34) with more than 9,000 

 cases, Bayer 205 was effective in early stages but useless after the central 

 nervous system was involved. Atoxyl also was not curative in later stages. 

 Tryparsemide showed more activity in early stages and also was the most 

 effective drug in later stages, even arresting a few apparently moribund 

 cases. However, this drug is quite toxic and dosage is usually spread 

 over a period of two or three months. In treatment of early cases, p-arseno- 

 phenyl butyric acid (24), germanin and pentamidine all seem to be 

 fairly effective. Orsanine seems to be active in cases showing involvement 

 of the central nervous system. Good results have been obtained also with 

 melarsen oxide which may be given orally or by injection and has shown 

 low toxicity and relatively rapid action. The trypanocidal activity of 

 tryparsemide, mapharsen and stilbamine involves effects on hexokinase 

 and other enzymes of trypanosomes (16). 



Chemotherapy has been less successful in Rhodesian sleeping sickness. 

 In recent years, apparent cures have ranged from 16 to 48 per cent during 

 various outbreaks in Tanganyika Territory. Particular drugs may differ 

 in their activity against T. rhodesiense and T. gambiense. Bayer 205 



