KALA AZAR. 22Q 



this rat trypanosomiasis can apparently be brought about through the agency of 

 both fleas and lice. In the flea there is apparently a developmental cycle of a dura- 

 tion of one week. 



There are many trypanosomes in birds, fish, frogs, etc. 



Trypanoplasma. 



The genus Trypanoplasma has a rather large blepharoplast, from which arise 

 two flagella. One extends forward as a free anterior flagellum, while the other 

 projects posteriorly, running along the border of the undulating membrane. This 

 genus is not known for man. 



Leishmania. 



The genus Leishmania includes three species: L. donovani, the para- 

 site of kala azar, L. tropica,the parasite of oriental sore andL. infantum 

 the cause of a leishmaniasis among children in northern Africa. 



The disease known as ponos, which exists in the Grecian islands Spezzia and 

 Hydra has been found by Galle to be a leishmaniasis. Nicolle has found a disease 

 of very young children (as a rule in the second year of life) in Tunis due to L. 

 infantum. This protozoon morphologically resembles L. tropica but is smaller. 

 It is found chiefly in the spleen, liver and bone marrow. The symptoms are extreme 

 anaemia, splenic, and to a less degree, hepatic enlargement. Irregular temperature, 

 rapid pulse and a mononuclear leukocytosis and transient oedema are also noted. 

 It can be inoculated into the dog and monkey; other animals are practically immune. 



A similar disease has been noted in Italy, Malta, and Portugal. L. infantum 

 grows rapidly in Novy MacNeal medium, in which medium L. donovani will not grow. 

 Furthermore inoculation of L. donovani into dogs and monkeys has been unsuccess- 

 ful. These are undoubtedly different species, inasmuch as in sections of India, 

 where tropical ulcer was common, there was no kala azar, and in Assam where kala 

 azar prevailed there were no Leishman-Donovan bodies to be found in smears from 

 the tropical ulcerations there present, except rarely in cases of general infection. 

 L. tropica has been cultivated by Nicolle. 



It is interesting that the parasite of kala azar cannot be cultivated except in 

 sterile media while that of oriental sore will grow in media contaminated with cocci. 



These parasites are typically intracellular, being within either polymorpho- 

 nuclears, which contain only one or two of the bodies, or in large mononuclears, in 

 which there may be as many as six. They may be packed, however, in phagocytic 

 endothelial cells. 



In kala azar smears taken during life we may find the bodies imbedded in a faintly 

 blue staining matrix; after death and in sections of tissue such an appearance is 

 not seen. In the spleen they are not found in the Malpighian bodies, but in the 

 phagocytic cells lining the lymph spaces. The parasites occur in the peripheral 

 circulation in about 80% of the cases. They abound in the liver and spleen. The 

 parasite is oval and about 2 X 3/. There are two distinct chromatin staining masses. 

 The larger nucleus is more or less spherical, peripherally situated, and stains faintly, 



