Parasitic infection among residents of an institution for mentally retarded persons.

Data on occurrence of intestinal parasites among resident and entering populations in a South Carolina institution for mentally retarded persons were examined. Following an eradication effort in 1973 for Trichuris trichiura, the prevalence of this parasite remained below 5 percent for the resident population, with the exception of 1974 and 1975, when small numbers of stool examinations occurred. Significantly higher proportions of the entering population, compared to the residents, harbored T. trichiura, Ascaris lumbricoides, Giardia lamblia, and Entamoeba histolytica. We concluded that annual examination and treatment can control trichuriasis; however, complete eradication may require examination following home visits by the resident population.