TREPANOSOMA GAMBIENSE 239 



TRYPANOSOMA GAMBIENSE 



Castellan! found that this trypanosome is the cause of sleeping- 

 sickness among the natives of South Africa, and the organism has 

 been found quite regularly in the blood, and also the cerebro- 

 spinal fluid sometimes as well, in this disease. The disease has a 

 long period of incubation (months), runs a long course usually, 

 and, at its full development, it is a meningo-encephalomyelitis. 

 This is characterized by hebetude, somnolence, and coma. 



FIG. 75. Trypanosomes; showing ordinary structural appearance on left; 

 in middle a trypanosome undergoing division; on the right a group dividing 

 in radial manner. (Tyson's Practice.) 



These symptoms are accompanied by disturbance of the motor 

 apparatus, oedema, irregular temperature, rapid pulse, emaciation, 

 skin eruptions, and death in coma. In these cases the parasites 

 may be seen in the blood slowly winding their way through the 

 corpuscles. The pathogenic action is due no doubt to some 

 toxin elaborated. 



The disease is transmitted from man to man by the tsetse-fly 

 (Glossina palpalis). In the fly it exists as a true parasite in a 

 host, and not merely passively. It becomes infective within 

 three days of biting and remains so for four weeks. 



The disease does not depend upon the age, sex of the individual, 

 nor upon drinking water, food, seasons, etc. 



The organism may be stained by the ordinary blood stains, 



