1088 



PATHOGENTC PROTOZOA 



duration ; Castellan! in 1903 found the parasite in the cerebro-spinal 

 fluid of well-marked eases of sleeping sickness occurring among 

 natives of Uganda. 



Clinical Signs. The disease begins with slight febrile attacks, 

 headache and increasing weakness, emaciation, swelling of the eyelids 

 and enlargement of the lymph nodes. The temperature increases, 

 edema of the extremities appears and the spleen enlarges. During 

 the last stages nervous symptoms predominate and the patient sleeps 

 day and night, but may have periods of excitement or convulsions, 

 yet finally sinks into deep coma and dies of exhaustion. 



FIG. 140. TRYPANOSOMA GAMBIENSE. Calkin, "Protozoology." 



Etiology. The disease is transmitted by the bite of the tsetse fly, 

 Glossina palpalis, which is apparently able to transmit the infection 

 mechanically immediately after biting an infected host, yet in most 

 flies the trypanosomes disintegrate and disappear from the intestinal 

 tract within four or five days. In from five to ten per cent of the 

 flies, however, the trypanosomes multiply in the intestinal tract, and 

 after eighteen to fifty-three days they again become infectious and 

 remain so for a long period, the parasites being found regularly in 

 the salivary glands and in the proboscis. 



It is possible that the disease is transmitted in other ways than 

 by Glossina palpalis; blood-sucking insects, such as stomoxys, 



