A study of intestinal protozoa including non-pathogenic Entamoeba histolytica from patients in a group of mental hospitals.

Twenty-five per cent of 174 patients residing in three mental hospitals were found to be infected with protozoa. Seven per cent of the patients were infected with Entameba histolytica. Isoenzyme characterization of the E. histolytica grown in culture showed that there were no pathogenic zymodemes of this organism in any of the specimens tested. (Am J Public Health 1982;72:178-180.)