XNli Annual Address. [February, 1917. 



On the other hand, the differentiation of kala-azar from 

 chronic malaria was not possible before the discovery of a 

 distinct parasite in the former, and up to quite recently it 

 remained very difficult on purely clinical grounds in many 

 cases. It is therefore not surprising that the two were for 

 long confused even by research workers, including myself in 

 mv report of 1897 on "the Assam epidemic and a little later by 



i great authority on malaria as sir nonaia txus* 

 I malaria to be mosquito borne. 



The Ravages of Epidemic Kala-Azar in Assam. 



who 



It is generally known that kala-azar spread through A> am 

 for a number of years causing a great mortal it v. but it is diffi- 

 cult to convey to those who have not seen its effects anything 

 like an adequate idea of the terrible nattfre of the affliction. 

 I show you a map the shaded portions of which were more than 

 decimated by the disease, while the figures indicate the years 

 in which different places and districts were invaded by the epi- 

 demic. The deeply shaded area between the Brahmaputra 

 river on the north, and the (Jaro and Khasia Hills on the south 

 including the Garo Hills, the southern portion of the Ooalpara 

 and Kamrup districts, and the whole of the sorely afflicted 

 Xowgong, lost about one-third of their entire population from 

 kala-azar. which spread about ten miles a year along the Grand 

 Trunk Road, which forms the main line of communication. The 

 more lightly shaded parts north of the Brahmaputra were 

 much less affected, communication with them being mainly b} 

 steamer across the river. At the time of my investigation . m 

 1896-97 the disease was at it- height in the Nou-ong district 

 the population of which in the decade 1891-1901 actually 

 showed a decrease of 315 per cent against an increase of 9 «° 

 16 per cent in the more easternly unaffected districts. Large 

 areas of land fell out of cultivation md e\eu at the head- 

 quarters town of Nowgong land absolutely lost it- value, hem 



quite unsaleable. When the tea gardens became Infected in 0* 



district and accurate figures were available, it was found that 

 the mortality in several hundred careful! v treated cases varied 

 from 90 to* 96 per cent. When I add that the unfortunate 

 patients suffered from fever with little inten -ion for on the 

 average nine months, during which thev were a burden on then 

 relatives, and that T have seen the last of thirteen ehfldf* in 

 a single family, all the rest having died of the di>ease, yon m*? 

 be able to form some faint idea of the havoc wrought W 

 such an epidemic in the course of its spread through <J 

 hundred and fifty miles of countrv during a period of twenty 

 five years. In the Mangaldai district, where I closely investi 

 gated the spread of the disease, I frequently met with squan 



patches of jungle in the midst of cultivated rice fields, and [0 

 inquiry found that the had belonged to a familv which » 





