A CASE OF HUMAN COCCIDIOSIS DETECTED IN THE 
PHILIPPINE ISLANDS, WITH REMARKS ON THE 
DEVELOPMENT AND VITALITY OF THE CYSTS 
OF ISOSPORA HOMINIS (RIVOLTA) 
By Frank G. Haughwout 
Protozoologist, Bureau of Science 
FOUR PLATES AND ONE TEXT FIGURE 
When Woodcock, in an appendix to a paper by Ledingham and 
Penfold, published in 1915(18) announced the discovery of sporo- 
zoan cysts in the stools of soldiers invalided home from Gallipoli, 
he reopened the entire subject of coccidiosis in man. Knowl- 
edge bearing on this subject was, at that time, on a very 
uncertain basis, and the general belief was that the coccidia of 
man were identical with those found in the rabbit and in the cat. 
Woodcock was not successful in his attempt to obtain develop- 
ment of the cysts and, therefore, could give only a very 
incomplete account of what he had found. 
However, confirmation came very quickly from Low and from 
Wenyon(i7) and within a year or two a number of cases of in- 
fections with Eimeria and Isospora were detected by workers in 
the war zones. Published figures of the cysts made it quite 
apparent that the species concerned were not the familiar para- 
sites of the rabbit and the cat. Circumstances connected with 
these findings indicated that the focus of infection lay in the 
eastern Mediterranean area, and subsequent observations have, 
in a large measure, confirmed this. On the basis of these reports 
I published a short paper in 1918(9) calling attention to the 
problem that seemed to be arising. At that time I raised a ques- 
tion as to the specificity of the parasites found in man, and also 
ventured the prediction that under war conditions, coccidial 
infections in man were likely to crop up at any time or place. 
Since the publication of that paper Dobell, in his admirable 
monograph on the coccidia of man, (3) has stabilized the situation 
as regards the identity of the organisms involved and has com- 
pletely analyzed the literature. Moreover, later reports, have 
shown that Isospora hominis (Rivolta, 1878) emend. Dobell, 
