HUMAN TRYPANOSOMIASIS 139 



trypanosomes are causes of disease in cattle, T. bnicci 

 and T. rhodesiense. No symptoms or changes have been 

 described in man in infections with this Rhodesian form 

 that have not been described in infections from the 

 Congo and Uganda. Anaemia is more frequent, orchitis 

 occurs in a larger proportion of cases, and death from 

 cardiac failure before the onset of cerebral symptoms is 

 more common. 



Diagnosis. The disease may be mistaken in the early 

 stages for malaria and typhoid fever and possibly pel- 

 lagra. In the later with any of the chronic forms of 

 intermittent, remittent, or " low fever," such as kala-azar. 



As the disease is confined to Tropical Africa, suspicion 

 may be excluded in patients who have not resided in that 

 country. The presence of enlarged glands and the 

 fugitive circinate eruptions are of great value in the 

 diagnosis. 



Certainty can only be obtained by finding trypanosomes 

 in the blood or fluid obtained by hypodermic puncture 

 of one of the enlarged glands, or by the results of the 

 injection of the blood into monkeys or other susceptible 

 animals, but with some of these, such as rats, the period 

 of incubation may be indefinitely prolonged. 



In the terminal stage the epileptiform convulsions and 

 the comatose condition might readily be mistaken for 

 other diseases. When this stage shows the peculiar 

 lethargy of sleeping sickness mistakes could hardly 

 occur. When cerebrospinal symptoms have set in try- 

 panosomes may not be found in the blood, but only in 

 the cerebrospinal fluid. This should be drawn off by 

 lumbar puncture, and centrifugalized, as the parasites are 

 usually scanty. Lumbar puncture can usually be readily 

 performed with the aid of a local anaesthetic, though it is 

 easier when chloroform is given. The patient should 

 lie on his side with the thighs flexed, and the back 

 arched as much as possible, to increase the space be- 

 tween the vertebrae. The space to be selected is between 

 the third and fourth lumbar vertebrae, and the needle 



