PROTOZOA IN THE CIRCULATORY SYSTEM 79 



increase in number by division, and the mass population 

 shifts to the anterior portion of the gut. By about the tenth 

 dav after feeding on the infected person, the flagellates 

 are often lodged in the proboscis of the fly. It is assumed 

 that these are introduced into man when the fly feeds 

 again. Adler and Ber (1941) succeeded in producing leish- 

 maniasis in 5 out of 8 human volunteers by bites of labora- 

 torv-bred Phlebotoimis papatasi which were infected arti- 

 ficially with Leishmauia tropica. 



1. Leishniania donovani (Laveran and Mesnil 1903) 



Svnonym: L. infantum Nicolle 1908 



This is the causative organism of Kala-azar or visceral 

 leishmaniasis which is widely distributed in parts of Eu- 

 rope, Africa, and Asia. In Europe it occurs in the southern 

 reeion which borders the Mediterranean Sea, such as 

 Portugal, Spain, Italy, Malta, Greece, and southern Russia. 

 In Africa it has been reported from Morocco, Algeria, 

 Tunisia, Libva, Abvssinia, Sudan, Northern Kenya, Ni- 

 geria, while in Asia south-eastern area of India, north of 

 Yangtze River in China, Turkestan, etc. The leishniania 

 body occurs in the macrophages, mononuclear leucocytes, 

 polymorphonuclears, etc., of the reticulo-endothelial sys- 

 tem of various organs such as the spleen, liver, bone mar- 

 row, intestinal mucosa, lymphatic glands, etc. When the in- 

 fected host cells are destroyed, the organisms will become 

 free in the blood plasma (Fig. 20, 2). 



The organism as seen in stained smears of spleen punc- 

 ture, is a rounded (1-3m in diameter) or ovoid (2-4m by 

 1.5-2.5|j) bodv (Fig. 20, ^-'^). Its cytoplasm is homogeneous 

 except one or more minute vacuoles. The nucleus is a com- 



