LEISHMANIASIS 19 



a. T. gambiense (Plate II, Fig. D, 1, 2, 3). This species 

 was named by Button in 1902 from specimens taken from a 

 fever patient in Tropical Africa. It is the cause of one type 

 of sleeping sickness. It ranges from 18 to 30 microns in 

 length and 1.5 to 2.5 microns in width. Polymorphism is 

 exhibited by this species there being short, stumpy forms 

 14 to 20 microns long, intermediate forms 20 to 24 microns 

 long, and long forms 23 to 33 microns long. Tsetse flies of 

 the genus Glossina transmit it from man to man. 



6. T. rhodesiense. This species is so similar to T. gam- 

 biense in morphology that the two are difficult to separate. 

 T. rhodesiense occurs in northwestern Rhodesia, and Portu- 

 guese and German East Africa. 



c. T. cruzi (Plate II, Fig. E) causes Chagas' disease in 

 Brazil. It is about 20 microns long and passes through a 

 leishmania stage, especially in the muscles. The bug, 

 Triatoma, is the transmitting agent. 



3. Methods of diagnosis. Blood films should be made and 

 stained as described for the malarial parasites (page 15). 

 The trypanosome nature of the organism can be recognized 

 at once but the species diagnosis is very difficult. 



Special Literature on Trypanosomiasis 



LAVERAN, A., AND MESNIL, F. : Trypanosomes and Trypanosomiasis. 

 2d ed. 1000 pp. Paris, 1912. 



Reports Sleeping Sickness Commission, Royal Society of London, 

 ' 1903. 



Sleeping Sickness Bulletin, London, 1908-1912. 



THIMM, C. A.: Bibliography of Trypanosomiasis. Sleeping Sick- 

 ness Bureau, London, 1909. 



C. Organisms that Cause Leishmaniasis in Man 



1. Classification. The organisms that cause leishmaniasis 

 are included among the Haemoflagellates, and belong to the 

 genus Leishmania. Forms with flagella usually appear only 

 in cultures. 



