KALA-AZAR 77 



Kala-azar 



About 1870 there began a great epidemic of a strange and 

 deadly disease in Assam, India, which spread up through the 

 Brahmaputra Valley. It was believed to have been imported 

 by the British from Rangpur, where a similar epidemic had been 

 raging for some time before. Whole villages and settlements 

 were depopulated and the country was terrorized by the " black 

 sickness." It is said that victims of the disease were driven out 

 of the villages, sometimes being made unconscious with drink, 

 taken into the jungle, and burnt to death. Some villages com- 

 pletely isolated themselves from the outside world, and still 

 others were entirely deserted for new and uninfected districts. 

 The natives were most severely affected, no doubt due both to 

 their filthiness and unsanitary habits and to their weak con- 

 dition as the result of almost universal malaria and hookworm. 

 Before the true nature of the disease was discovered it was usu- 

 ally diagnosed as "severe malaria"; one physician concluded 

 that it was excessive hookworm infection, since he found hook- 

 worms almost universally present in kala-azar sufferers. 



This Assam epidemic, which lasted for many years, is the only 

 recent case of a great epidemic of kala-azar, although the disease 

 now occurs endemically in many parts of India and Southern 

 China, and is spreading in the Sudan region of North Africa. 

 It has been pointed out that the endemic parts of China, chiefly 

 along the north bank of the Yangtse River and its tributaries, 

 correspond closely in latitude and climate to a considerable part 

 of southern United States, and since kala-azar is believed by some 

 to be spread by bedbugs and perhaps other vermin, there is danger 

 that once introduced it might become endemic in America. 

 A single case has been found in Brazil, contracted in a region 

 where another form of Leishmaniasis is prevalent. How this 

 case should be explained is difficult to know. 



Transmission. — In spite of numerous experimental investiga- 

 tions to discover the mode of transmission of the kala-azar para- 

 site, Leishmania donovani, the question is still obscure. Captain 

 Patton, of the British Medical Service in India, adduced some 

 evidence that the common Indian bedbug, Cimex hemipterus 

 (rotundaius) , is the normal intermediate host and transmitter 

 of kala-azar. Using laboratory-bred bugs, Patton succeeded in 



