An Ecological Study on Hemolytic Streptococci in a Baby Asylum

Abstract

An ecological study regarding to carrier state of hemolytic streptococci was carried out, in a baby asylum at Setagaya in Tokyo, throughout a year from March 1956. Almost of isolates were group C streptococci from March to June, however, the streptococci completely disappeared in July. From autumn to winter, group A streptococci became dominant, among which types 4, 6 and 55-15 being prevalent. Group B streptococci seemed to endemically exist in this population except for summer. Sporadic appearances of streptococci other than group A, B and C were also observed.
In general, positiveness of hemolytic streptococci in this asylum seemed to be influenced with the age of individual baby and the frequency of contact with surrounding enviroments. Existence of socalled chronic carrier state was doubtful although some cases of higher susceptibility to streptococcus infection were observed.