1.A survey for intestinal protozoa was made of 401 freshmen in a Philadelphia college. About 95 per cent came from homes in Pennsylvania and New Jersey, and few had traveled extensively.
2.A single normal stool was examined for each person, stained slides being employed as well as fresh smears in saline and iodine. The stained slides revealed 167 protozoan infestations as against 147 for the fresh smears and the two methods combined yielded 176.
3.One or more species of protozoa were found in 33.1 per cent of the students, 4.5 per cent being carriers of Endamoeba histolytica and 3.5 per cent harboring Dientamoeba fragilis.
4.Only one of the carriers of E. histolytica suffered from symptoms which might be attributed to the presence of the amoeba.