56 DISEASES DUE TO PROTOZOA 



Kala-azar. 

 DEFINITION. 



A chronic, specific, infective, febrile disease, caused by Leishmania 

 donovani ; characterized by irregular fever, enlargement of the spleen 

 and liver, emaciation and anaemia, frequent hyperpigmentation of the 

 skin, and accompanied by a heavy mortality. 



HISTORY. 



1869. It was noticed by British officers in India, decimating and, 

 in some instances, depopulating numerous districts of the Garo Hills. 

 The Garos called it " kala-azar," or the black fever, 



1875. It became epidemic with a very heavy mortality. 



1882. The first account of it was published by Clarke. 



1889. It spread to Assam along the lines of communication. 



1900. Sir William Leishman found the parasite in the spleen of 

 a soldier at Xetley, but he did not publish it until 1903, in which vear 

 Donovan found the parasite by splenic puncture during life. 



1907. Patton found the parasite in the leucocytes of the peripheral 

 blood, also that it became flagellated in the alimentary canal of bugs. 



DISTRIBUTION. 



It is endemic, and may become epidemic in East India, Assam, 

 Madras and Calcutta. It is present in Arabia, Ceylon, Burma, Indo- 

 China, China, the Yangtse valley, Sudan, Egypt, Tunis, Algeria, 

 Sicily and Portugal. 



The Indian epidemic began in the Lower Bengal at the foot of the 

 Garo Hills, slowly advancing up the valley of the Bramaputra, travel- 

 ling 100 miles in seven years. 



■It followed the lines of intercourse, attacking first the larger 

 stations. Isolated villages seemed to escape. As it spread into new 

 villages ahead it died out in those first attacked. 



It seemed to cling to a place for about six years, and then died out 

 without apparent cause. A house would appear to retain the infection 

 for months. 



The disease terrorized the natives, those afiflicted were expelled from 

 their villages, made semi-drunken, and taken into the bush to be 

 destroyed. 



There have been sporadic cases in other parts difficult to account 

 for, although they seemed to be typical cases of Kala-azar. 



AETIOLOGY. 



The disease is spread by Leishmania donovani. 



The carrier blamed by Donovan is a Conorhinus. 



The predisposing causes are explained by the habits of bugs thus : — • 



