KALA-AZAR 157 



Cases are said to be met with in the endemic area in 

 which the symptoms throughout are of a mild nature. 



The symptoms referable to the circulatory system are 

 chiefly dependent upon anemia. In the early stage the 

 pulse is less rapid than might be anticipated from the 

 height of fever present, while later, owing to the anaemia, 

 its frequency is out of proportion to the temperature, and 

 is full, though very soft. Pulsation of the carotids is 

 often noticeable, and haemic murmurs are common, as 

 also is palpitation on slight exertion. 



Anaemia is a constant symptom of kala-azar. Its 

 degree varies in different cases and at different periods 

 of the disease, but is usually considerable, though not 

 extreme. It commences early in the disease and there is a 

 progressive reduction in numbers of both red corpuscles 

 and leucocytes. Instead of the usual 5,000,000 red cor- 

 puscles to the cubic millimetre, only half that number 

 may be present, though 3,000,000 or 3,500,000 are more 

 common counts. The haemoglobin value of the red 

 corpuscles is only slightly reduced. The diminution in 

 the number of the leucocytes is much more marked than 

 that of the red corpuscles, their numbers varying from 

 3,000 down to 1,000, or even to only 500 to the cubic 

 millimetre. This marked leucopenia is, according to 

 Rogers, diagnostic of kala-azar. 



The decrease chiefly affects the polymorphonuclear 

 leucocytes, while the mononuclear elements show a 

 considerable relative increase. The results of differential 

 blood counts are commonly as follows, the figures given 

 representing percentages : Polymorphonuclears, 40 to 60 ; 

 lymphocytes, 20 to 30 ; large mononuclears, 13 to 16. 



Although the specific parasite may be met with in the 

 peripheral blood, it occurs so sparingly, especially in 

 the early stages of the disease, that the diagnosis can 

 rarely be made by blood examination. It occurs in 

 the polymorphonuclear and in the large mononuclear 

 leucocytes, and the method which affords the best chance 

 of finding it is to centrifugalize 2 or 3 c.c. of blood, and 



