Hemolytic Streptococci Recovered During an Epidemic in a Kindergarten *

The methods of Lancefield and of Griffith for grouping and typing hemolytic streptococci have greatly facilitated studies on the relationship of the hemolytic streptococcus to human disease. Strains from human disease fall into Lancefield's Group A by the precipitin test.5 Exceptions occur, but they are rare.' Group A consists of about 30 types which can be identified by another precipitin test of Lancefield4 or by Griffith's slide agglutination technic.3 The importance of these methods can be demonstrated by the description of a small epidemic of scarlet fever which was recently studied. The epidemic occurred in a New Haven kindergarten during the late winter of 1940-41 and afforded an opportunity for study of the spread of the epidemic-type of hemolytic streptococcus among the children and their families. Thirteen of the 46 kindergarten children became ill during the epidemic. Eleven of these had scarlet fever and 2 had streptococcal cervical adenitis. Hemolytic streptococci recovered from the throats of the sick children were identified as Group A, type 3 organisms. Griffith's slide agglutination method was used for the determination of type.' Twenty-three of the 46 children had hemolytic streptococci in their throats at some time during the 4 months of study. Eighteen carried organisms of the human pathogenic group, Group A. One child had Group B organisms in his throat; another, Group C; and 3 children carried Group G strains. The streptococci from 2 of the children belonged in Group A but they were not of the epidemic type, type 3. These 7 children remained well as did their families. Of the 16 children who had type 3 streptococci in their throats, 13 became ill and 5 of these infected other members of their families. Three children remained well but carried the organisms to cause disease in their families. In all, 8 families (a total of 18 family members, exduding the kindergarten children) became ill with a type 3 infection.