[Seroepidemiologic study of measles in 2 populations of children under 10 years of age from the metropolitan area].

Measles antibodies were investigated by direct immunofluorescence in 274 samples from infants and 245 samples of children from 1 to 10 years of age. Antibodies were present in 74% of children under 3 months of age, decreasing to 42% at age 11 months. Positive results were obtained in 60% of children from 1 to 4 years of age, decreasing to 47% from 5 to 10 years of age. Overall, infants had 64% positive tests and children 54%. Accordingly, a greater susceptibility to infection by measles is found in infants above 3 months of age and children from 5 to 10 years of age.