114 TRYPANOSOMES AND SLEEPIxNG SICKNESS 



form is that in which the predominating symptoms result from 

 an enlarged but insufficient thyroid gland — goitre, cretinism, con- 

 vulsions, swollen skin and various functional disturbances, includ- 

 ing imperfect heart and intellectual defects. Another chronic form 

 is that in which the heart is especially affected. The fact that 

 the parasites have a special predilection for the heart muscles 

 makes this form of the disease very common. The results of locali- 

 zation of the parasites in the nervous system have already been 

 mentioned. The intensity of the motor disturbances, varying 

 from paralysis or spasmodic convulsions of a single muscle to 

 complete paralysis or convulsions of the whole body, has no rela- 

 tion to the degree of intellectual affection, which may vary from 

 a simple cretinoid condition to complete idiocy or infantilism. 



It is doubtful whether the disease is ever recovered from entirely 

 if left to run its course. Sometimes the symptoms become 

 gradually less intense, in other cases they become worse and new 

 ones develop, or recurrences of acute sjanptoms may develop, 

 due either to reinfection or to a loss of the trypanocidal power of 

 the blood. 



Treatment and Prevention. — The treatment of Chagas' dis- 

 sease is still in the experimental stage but there is some evidence 

 that tartar emetic may prove to be of great value in dealing with 

 it, at least in early stages. In fact it was the success obtained by 

 Vianna in combating the disease with tartar emetic that first 

 suggested to him its use against Leishmanian diseases. 



Prevention of the disease consists largely in avoiding and ex- 

 terminating the barbeiros. It is practicall}' impossible to keep 

 the bugs out of mud or thatched houses. For this reason the re- 

 building of houses with other material is being urged everywhere 

 in Brazil and with good results. The town of Bello Herizonte, 

 for example, which was formerly termed " a nest of cretins " is 

 now nearly free from Chagas' disease, due to the remodeling of 

 the houses. People traveling through infected districts can 

 readily protect themselves by sleeping under mosquito nets and 

 by avoiding the native houses. There is said to be no danger 

 of being bitten by the bugs in daytime or in the presence of arti- 

 ficial light, since they come forth only in the dark. 



The extermination in the \'icinity of villages of armadillos and of 

 the various rodents which harbor the trypanosomes would be a 

 valuable aid in the reduction of the disease. 



