682 



INFECTION AND IMMUNITY. 



Douriiie. 



evansi is pathogenic for "nearly all animals." It is 

 longer than T. brucei. 



Surra affects horses chiefly, and has caused immense 

 losses in India and in the Philippine Islands. In India 

 it is certainly transmitted by certain flies, and the same 

 probably is true in the Philippines. Musgrave and Clegg 

 demonstrated also that fleas may be of great importance 

 as carriers. By this means they were able to transfer 

 the disease from dog to dog, rat to rat, and rat to dog. 

 They frequently found the parasites in native rats and 

 believe that this animal may serve as a host in which the 

 disease is maintained. Cattle are susceptible to infec- 

 tion, but the disease is less malignant in them and runs 

 a long course; hence, they may be an important factor 

 in maintaining an epidemic. The disease is also trans- 

 mitted from horse to horse. In India, camels, elephants 

 and buffaloes also suffer from the disease. Surra resem- 

 bles nagana in its clinical and anatomic aspects. 



Doflein gave the name of Trypanosoma equiperdurn to 

 an organism described by Rouget in horses and asses 

 suffering from dourine. Laveran and Mesnil call it T. 

 rougetii. According to Rouget, the parasite resembles 

 T. brucei closely. Doflein (1901) states that a nucleus 

 and vacuole have not been seen. Dourine occurs in 

 Algiers, southern France, Navarre and in the Pyrenees 

 districts of France and Spain. The infection is trans- 

 mitted by coitus and is limited largely to animals which 

 are used for breeding. Ulcerations, particularly of the 

 genitals, are characteristic. That it is not transmitted 

 by insects may be due to the absence of suitable insects 

 from these localities. The identity of dourine with 

 surra or nagana is not yet determined. It is said to be 

 more chronic than surra. Doflein recognizes the organ- 

 ism as an independent parasite. Infection may be trans- 

 ferred to dogs, white mice and other animals. 



Trypanosoma equinum (Voges) or T. elmassianii is 

 Caderas. the parasite found in mal de caderas, a disease of horses 

 in South America, resembling surra, nagana and dourine. 



Two different species have been found in the blood of 

 South African cattle: T. theileri (Bruce, 1902) and T. 

 transvaaliense (Laveran and Mesnil, 1902). The char- 

 acteristic feature of the latter is the location of the 



Mal le 



Infections 

 of Other 

 Animals. 



