TRYPANOSOMIASIS 499 



Course. — ^The course is usually one to two months, rarely 

 does death ensue in one to two weeks. 



Prognosis. — ^Bad. Nearly all cases die. 



Treatment. — ^In permanently infected districts, arsenic 

 (grs. X to XV daily for ten days in powder form as a bolus or 

 electuary) has given good results. Atoxyl (gj to v of a 4 

 per cent, solution subcutaneously) given at the same time 

 with arsenic (grs. x to xv per os) was less successful. 



Prevention. — ^Ridding the infested districts of fly harbors 

 (cutting brush, draining fields, tillage, cleanliness about 

 stables), pasturing only at night when the flies do not swarm, 

 applying agents to the skin to keep flies away (creolin, 

 petroleum), and encouraging the growth of citronella grass 

 are helpful. 



In non-infected localities quarantine should be established 

 against animals from infected countries. The killing and 

 cremation of all infected animals are indicated. By taking 

 the temperatures frequently during fresh outbreaks, making 

 blood examinations and animal inoculations (rats, mice) 

 the animals harboring the trypanosomes may be identified 

 and destroyed leading to the eradication of the disease in 

 districts and countries where it has not yet gained a firm 

 foothold. 



Nagana (Tsefae Disease). — ^Definition. — Nagana is an African 

 trypanosomiasis of horses and cattle, more rarely in sheep, 

 goats, and dogs, due to the Trypanosoma brucei and trans- 

 mitted by the tsetse fly. In character it much resembles 

 surra. 



Occurrence. — ^Nagana was formerly widespread in Central 

 and South Africa, but of late years has grown less common 

 (disappearance of virus-carrying game?). Low, swampy, 

 river coimtries are most infectious. 



Etiology. — ^The Trypanosoma brucei, which is transmitted 

 from animal to animal by the bite of the tsetse fly (Glossina 

 morsitans) or other closely related flies (Gl. fusca, Gl. 

 pallidipes, etc.). 



Symptoms. — ^In horses the period of incubation is two to 

 ten days. The symptoms are high fever (104° to 105.8° F.) ; 

 congestion of mucous membranes (eye); edematous swelling 



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