INTESTINAL PARASITIC INFECTIONS IN FORSYTH COUNTY, NORTH CAROLINA. II. AMEBIASIS, A FAMILIAL DISEASE

Abstract

About 20% of the school children in grades 2-5 in 6 schools (1934 in all) were examined. The survey was design to permit valid comparisons of the racial and the urban-rural groups. The calculated efficiency of the diagnostic laboratory methods for the demonstration of Entamoeba histolytica was 59.0%. The observed prevalence of E. histolytica was 6.1%. The children found infected by this parasite served as probands or leads to the "positive" families. A limited number of apparently uninfected children were utilized similarly for the selection of the "negative" control families. In 94 "positive" families of infected children, comprising 619 individuals, 211 infections by E. histolytica were found, an average of 2.2 cases per family, and a prevalence of infection of 34.1% approximately 30 times as frequent as among family members of apparently uninfected children. No significant differences in prevalence of infection between Negroes and whites were observed.