MASTIGOPHORA 1095 



The parasite is probably transmitted by some insect, either cimex 

 (Rogers), or by the dog flea, Ctenocephalus canis (Wenyon), or a 

 plant-feeding bug, Conorhinus, which occasionally sucks blood. 



Animal Pathogenicity. Wenyon in 1913 8 inoculated a dog with 

 splenic emulsion from a man who died in London of kala-azar con- 

 tracted in Calcutta. The parasite has been successfully carried 

 through five animals, and in 1915 an examination of the bone marrow 

 showed not only typical leishmania, but also a few large, well-marked 

 leptomonad forms. Similar forms were described by Escomel in 1911, 

 from South American dermal lesions. Monkeys may also be infected. 



Leishmania tropica (Delhi or Aleppo boil) is the organism found 

 in a local skin affection variously termed Delhi boil, Aleppo boil or 

 tropical ulcer. While it is probably transmitted by some insect, 

 there is as yet no definite proof. The incubation period is about 

 two months, while the disease, once manifest, lasts twelve to eighteen 

 months and is followed by immunity for life. 



The parasite, which was first described by J. H. Wright, 9 shows 

 minor differences from leishmania donovani, particularly a variable 

 morphology, all gradations, from the usual oval to elongated narrow 

 forms with pointed ends, being found. 



Cultures may be obtained on the N. N. N. blood agar, which 

 develop into leptomonads, as with Leishmania donovani. Dogs and 

 monkeys are susceptible to artificial inoculation, and it is possible 

 that in nature the disease is carried from dogs to human beings by 

 some insect. 



Leishmania infantum (Infantile Splenomegaly) was described by 

 Nicolle in 1909 from cases of infantile splenomegaly occurring in 

 Northern Africa. It is, however, not limited to this region, but 

 occurs throughout the whole Mediterranean District. Javarone 10 

 described 110 cases observed in Naples from 1913 to 1920. The 

 disease resembles kala-azar in all respects, except that the patients 

 are young children, and it is possible it is the same disease. With- 

 out treatment the disease, like kala-azar runs a progressive course 

 almost always leading to death. The parasites are found in abun- 

 dance in the liver, spleen and bone marrow at autopsy and may be 

 cultivated in the usual way on the N. N. N. blood agar. 



8 Wenyon, Jour. Trop. Med. and Hyg., London, 1915, xviii, 218. 



9 Wright, J. H., Jour. Med. Res. Bost. 1903, x, 472. 



10 Javarone, N., Infantile Leishmaniasis hi Naples and Neighborhood, Tropical 

 Diseases Bulletin, London, 1920, 16, 454, 



