630 LEISHMANIOSIS 



as yet quite ignorant of many of the processes at work in the 

 body during a trypanosomal infection, and of the causes of the 

 symptoms and other morbid effects. 



LEISHMANIOSIS. 



Under this term there are grouped three human diseases, but 

 the exact zoological place of the parasites among the protozoa 

 cannot be said to be at present definitely settled. These 

 organisms are the Leishmania donovani, associated with the 

 human disease, kala-azar ; Leishmania infantum, derived from a 

 similar disease occurring in children; and Leishmania tropica, 

 which has been found in a skin ulceration of widespread 

 geographical distribution. Microscopically the organisms are 

 practically identical, but at present it is convenient to look upon 

 the three species as being distinct. 



Leishmania Donovani. Leishman noticed in several soldiers 

 invalided from India for remittent fever and cachexia that the 

 most careful examination of the blood failed to reveal the 

 presence of the malarial parasite. From the fact that such 

 patients had almost invariably been quartered during their 

 service at Dum-Dum, an unhealthy cantonment near Calcutta, 

 he suspected he had to deal with an undescribed disease. In 

 1900 he noticed in the spleen of such a case peculiar bodies 

 which, from comparison with certain appearances found in 

 degenerating forms of Tr. Brucei, he suggested might be 

 trypanosomes, and on publishing his observations in 1903 he 

 put forward the view that trypanosomiasis might prevail in 

 India and account for the aberrant cases of cachexial fever met 

 with there. Soon after Leishman's paper appeared, his observa- 

 tions were confirmed in India by Donovan, and the bodies 

 associated with the disease are usually called the " Leishman " or 

 the " Leishman-Donovan " bodies. They were found by Bentley, 

 and later by Rogers, in the disease known in Assam as kala-azar, 

 the pathology of which had long puzzled those who had worked 

 at it, from the fact that, while it resembled malaria in many 

 ways, no parasite could be demonstrated to occur in those 

 suffering from it. This disease has gone under various synonyms, 

 e.g. cachetic fever, Dum-Dum fever, non-malarial remittent 

 fever, but is now recognised as a single entity. 



Kala-azar (or "black disease," so called from the hue 

 assumed by chocolate-coloured patients suffering from it) has 

 been known since 1869 as a serious epidemic disease in Assam, 

 where it has spread from village to village up the Brahmaputra 



