A STUDY OF THE BLOOD IN DENGUE FEVER WITH PAR- 
TICULAR REFERENCE TO THE DIFFERENTIAL COUNT 
OF THE LEUCOCYTES IN THE DIAGNOSIS 
Or SHE DISEASE. 
By E. R. Srirt.? 
(From the Laboratory of the United States Naval Hospital, Canacao, P. I.) 
Dengue resembles a composite photograph in that it is by adjusting and 
subordinating the symptomatology that one arrives at a diagnosis of the 
disease—the moment one symptom stands out preéminently, there is a 
strong probability of mistaking dengue for some other affection. In 
proof of this statement may be instanced a few cases which have been 
observed during the past six months and in which at first another disease 
had been diagnosed. 
1, A case presenting unusually severe pains about the regions of the knees 
and wrists. This was diagnosed as acute articular rheumatism. <A careful 
examination failed to show any swelling and the pain was more associated with 
the structures adjacent to it than with the joint itself. A rapid survey of the 
other, but less pronounced, symptoms, together with the blood examination, 
showed the case to be one of dengue. 
2. A case where there was a gradual, step-like rise of temperature with an 
unusually heavily coated tongue and a marked right iliac tenderness. It was 
only when a most characteristic rash appeared and the temperature fell to normal 
by crisis that a correct diagnosis was made. It may be stated that negative 
agglutination caused this case to be very carefully studied, and it was in this 
connection that the blood changes, to which I shall presently refer, were first 
observed. 
3. A man admitted to the hospital with a most profuse general rash, the 
case having been diagnosed as measles. From the standpoint of the rash it 
certainly resembled measles, but a marked leucopenia with a rather charac- 
teristic differential count, together with the presence of less prominent symptoms, 
showed the case to be dengue. 
4. Two cases in which there was an almost entire absence of eruption, but 
a history of previous malarial attacks, resembled estivo-autumnal fever, but 
the negative evidence as to parasites and the striking difference as to blood 
findings, made the diagnosis easy. 
In fresh dengue blood I have observed most suggestive vacuolation. 
There seems to be more of what might be termed a protoplasmic milkiness 
*Read before the third annual meeting of the Philippine Islands Medical 
Association at Manila, March 2, 1906, by E. R. Stitt, M. D., surgeon and 
lieutenant-commander, United States Navy. 
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