Prevalence of non-group-A beta-hemolytic streptococci in childhood pharyngitis

We studied the prevalence of non-group-A beta-hemolytic streptococci (NGAS) in the pharyngeal cultures of symptomatic and asymptomatic children. Throat cultures were obtained by house officers in the Emergency Department at Children's Hospital of Pittsburgh to aid in the evaluation of children with symptoms or signs of pharyngitis, or both. A total of 929 throat cultures were read in four discrete periods between July 1982 and February 1984. A control group was composed of 414 asymptomatic children, recruited contemporaneously with study subjects. beta-Hemolytic colonies were evaluated for bacitracin susceptibility and grouped by the Streptex method. The prevalences of NGAS in symptomatic and control children were 6.5% (60/929) and 1.0% (4/414), respectively (P less than .01). Seasonal variation in the recovery of NGAS from symptomatic children was suggested by higher relative and absolute recovery rates of NGAS during warm weather. This study demonstrates an association between NGAS and sporadic pharyngitis in school children but does not establish causality.