KALA-AZAR 567 



organism in the trypanosoma direction. Others have looked 

 on it as a piroplasma, but Minchin suggests that in the present 

 incomplete state of knowledge it may be well to place it in a 

 provisional genus, Leishmania, of the flagellata. In this genus 

 there would be at present two species, the Leishmania donovani, 

 and the organism seen in Dehli sore, Leishmania tropica, 

 presently to be alluded to. 



The question arises, given that the Leishmania donovani is 

 the cause of kala-azar, how is infection spread 1 ? On this we 

 have as yet no certain information. The fact that in some 

 centres of the disease natives who are supplied with good water 

 are less liable than those who rely on the ordinary polluted 

 native cisterns, has led to the opinion that water may be the 

 carrier of infection. On the other hand, the possible relation- 

 ship of the organism to the trypanosomata naturally suggests 

 the idea of an insect as an intermediary, and Rogers has brought 

 forward some evidence that the bed-bug is the extra-human host, 

 but the organism has not as yet been demonstrated in the body 

 of this insect. It has been objected to the theory of an insect 

 carrier that the organism probably does not occur in the blood, 

 but it has been pointed out that invisible spirillary forms may 

 be the instruments of infection, and that such may exist in the 

 blood. It may be said here that all attempts to communicate 

 the disease to animals have been hitherto unsuccessful. 



With regard to kala-azar as a whole, we may say that we are 

 dealing with a disease fairly widespread in various sub-tropical 

 regions, which is, there is every reason to believe, a separate 

 entity. All attempts to include it among the malarial cachexias, 

 which clinically it so much resembles, have failed. In this atypical 

 cachexial fever there is always present a parasite of very special 

 characters belonging or closely allied to a group which contains 

 many varieties capable of giving rise to similar diseases. 

 Beyond this we cannot go, but at present we must admit that 

 there is strong presumptive evidence of the parasite described 

 being the cause of the disease. 



Methods of Examination. The Leishmania donovani can 

 be readily seen in films or sections of the organs in which we 

 have mentioned its occurrence. These should be stained by the 

 Romanowsky stains. Fluid taken from the enlarged spleen during 

 life may be examined, but it is probable that in this disease 

 puncture of the spleen may not be a very safe operation, as 

 death from haemorrhage from this organ is a not uncommon 

 natural terminal event. During life the main points on which 

 a pathological diagnosis may be based are the absence of 



