Strongyloidiasis in an institution for mentally retarded adults

A serologic and epidemiologic survey was undertaken to explain the high incidence of eosinophilia (14.1%) in nine of 64 residents of a facility for mentally retarded adults in Pennsylvania. Seven residents had antibodies to Strongyloides stercoralis as determined by an IgG enzyme-linked immunosorbent assay system (10.9%) and five (71.4%) of this subset had persistent eosinophilia, suggesting a strong association. Sex, race, age, ward, degree of retardation, and medication were not associated with eosinophilia. Stool examination revealed S stercoralis larvae in two residents with S stercoralis antibodies and eosinophilia. Follow-up studies after thiabendazole treatment of the residents with S stercoralis antibodies showed resolution of eosinophilia and disappearance of S stercoralis antibodies in most. Eosinophilia in an adult institutional setting may be associated with strongyloidiasis, even in a nonendemic area. The enzyme-linked immunosorbent assay for antibody to S stercoralis may be useful in diagnosing or monitoring therapy of strongyloidiasis.