Up to the present about 150 cases of infection with Isospora hominis (Rivolta) Dobell, 1919, have been reported (1). The earlier cases, roughly one-half of them, were recorded during and immediately following the Great War and there was a suggestion that these infections were contracted by service in the Near East or by association with troops returning from that area. Seven infections were discovered in American soldiers returning from overseas; but four more were found in Americans who had had only home service (2). The geographical distribution of cases more recently reported indicates that the area of endemicity probably includes all tropical and subtropical countries and possibly is world-wide.
Only one case of infection with I. hominis has heretofore been reported from the Philippine Islands, by Haughwout (3) who suggests that the patient may have contracted the infection in the United States.