Natural Occurrence of Hemolytic Streptococci in Normal School Children

Abstract

Findings of the first 2 years of a study of 3d and 4th-grade children in 3 Nashville schools serving 3 different socioeconomic areas are presented. Hemolytic streptococci were serologically grouped and typed and carrier rates determined. Carrier rates were highest in the best socioeconomic area, (60% in 1953-54; 42% in 1954-55). The highest for the middle and lower socioeconomic areas were 45% and 26%; and 41% and 30%, respectively, in 1953-54 and 1954-1955. Cumulative percentages of children with positive throat cultures were 88%, 75%, and 82% for high, middle, and low areas, respectively, in 1953-54 and approximately the same for all 3 schools, about 60%, in 1954-1955. Of all hemolytic streptococci recovered, 83.7% were Group A; 4.7% Group C; and 9.8% Group G. Approximately 52% of Group A strains were typable, types 1, 6 and 12 occurring most frequently. Types changed in each school in each study year. Effect of presence or absence or absence of tonsils on carrier rates was not consistent. Degree of crowding in home and school and meteorologic conditions did not seem to influence carrier rates directly.