[Reprinted from the Boston Medical and Surgical Journal 
of September 1, 1898.] 
A NOTE ON THE DURATION OF EOSINO- 
PHILIA IN TRICHINOSIS. 
THOMAS B. BROWN, M.D., BAI/TIMORE, MD. 
In a comparatively recent number of the Boston 
Medical and Surgical Journal,x Dr. Richard C. Cabot, 
in discussing eosinophilia in trichinosis (the first ac- 
count of which had been given by me in the Johns 
Hopkins Bulletin, April, 1897, followed by a complete 
report in the Journal of Experimental Medicine, Yol. 
111, No. 3, of three cases in which a marked eosino- 
philia, between 45 per cent, and 68 per cent, had been 
found in the blood, and living trichinae in the muscle), 
remarked that it would be interesting to know how 
long the eosinophilia lasted after the cessation of the 
acute symptoms. 
This question had also occurred to me, but unfortu- 
nately, all our three cases left the hospital and the city 
while still showing a marked eosinophilia, 16.8 per 
cent, in the first, 17.6 percent, in the second and 34.7 
1 December 30,1897. percent, in the third, with a leucocytosis of 11,000 
per c. mm. in the first, and 9,000 per c. mm. in the 
second and third cases. Recently, by a lucky chance, 
the third case has again come under my observation and, 
as there had been no symptoms since leaving the hos- 
pital (January 22, 1898) to suggest another trichinotic 
infection, I took the opportunity to examine his blood 
to see whether any trace of the old eosinophilia re- 
mained. 
The count made on July 10, 1898, was: 
Leucocytes (per c. mm.) 
7,000 
Polymorphonuclear neutrophiles 
68% 
Small mononuclears 
23% 
Large mononuclear and transitional forms . 
6% 
Eosinophiles 
3% 
That is, practically, a normal number of leucocytes per 
c. mm., and normal percentages of the various forms, 
thus showing that the eosinophilia had entirely disap- 
peared within the five months subsequent to his leaving 
the hospital. This one would naturally expect if 
the eosinophilia is related to the acute stage of the 
trichinotic infection, as seems to be the case. Never- 
theless, that there is an increase of the eosinophiles in 
the blood for a considerable time after the cessation of 
the acute symptoms, is highly probable, when we con- 
sider the very great increase in the number of these cells in the blood, and the fact that a considerable 
length of time must elapse after the enormous new for- 
mation has ceased, before a sufficient number has been 
destroyed to bring their proportion again within normal 
limits. 
The fact that all three of our cases, leaving the hos- 
pital after their symptoms had. practically ceased, had 
still a marked eosinophilia, shows that for a certain 
length of time at least, the increase is maintained, al- 
though gradually lessening.