TROPICAL KALA-AZAR 



1291 



Leishmaniasis. According to Christopherson the drug was dis- 

 covered by Basil Valentine in the sixteenth century, and accident- 

 ally caused the death of several monks, and thus acquired its 

 name ' antimony ' — i.e., anti-moine, against the monk. In 1914 

 Castellani in Ceylon used this method combined with oral therapy 

 for the treatment of tropical kala-azar. In 1915 Rogers treated 

 cases in India in the same manner, and later in the same year Rogers 

 and Hume administered this treatment to six cases of kala-azar in 

 Europeans. Christopherson has successfully employed the same 

 method in the Sudan; and this has now become the recognized 

 method of treatment. 



In addition to the above, much work has been done by the Indian 

 investigators, such as Mackie, Cornwall, and others, as well as by 

 Manson, Low, Statham, and others. 



Climatology. — -The disease is especially spread through the tropics, 

 but is unknown in Tropical America and Oceania. It is found in 

 the Sudan, Arabia, India and Ceylon, Burma, Indo-China, and 

 China. 



etiology. — Kala-azar is caused by a herpetomonad parasite 

 called Leishmania donovani R. Ross, 1903, described on pp. 369-370, 

 which lives especially in the endothelial cells of bloodvessels and 

 lymphatics, and is especially numerous in the spleen, the liver, and 

 the bone-marrow, but is also found in other organs, such as the 

 lungs and the kidney. Especially must be mentioned its presence 

 in the mesenteric lymphatic glands, and in ulcers of the intestinal 

 mucosa. 



It can also be found in mononuclear and polymorphonuclear 

 leucocytes in the peripheral blood, but only occasionally, as at other 

 times it is most difficult to find it in this situation. It also at times, 

 but very rarely, lies in the hollow of the biconcave disc of a red 

 blood cell, thus looking as though it was contained therein. The 

 parasites have been cultured from the blood by using the N.N.N, 

 medium. 



They are most abundant in the blood towards the fatal end of the 

 illness, and during fever or the presence of intestinal symptoms. 

 They are said to have been found in the motions during an attack 

 of kala-azar dysentery, and also in the scrapings from intestinal 

 ulcers. They have also been found in papules and ulcers in the 

 skin. 



As they occur in the peripheral blood and in the skin, it is possible 

 that they may pass into the alimentary canal of some blood-sucking 

 arthropod, but these animals are often naturally infected with 

 flagellate parasites of the leptomonad, crithidial, and trypanosomal 

 types, and therefore the mere finding of a flagellate in the interior 

 of a blood-sucking arthropod which has been fed upon a man or 

 animal infected with L. donovani is worthless from an aetiological 

 point of view. 



As they occur in the peripheral blood and in the intestinal mucosa, 

 they can equally escape in the faeces in the form of cysts, and thus 



