GROUP A STREPTOCOCCAL INFECTIONS IN A CHILDREN'S HOME

Abstract
School-age children living in a children's home had pharyngeal cultures made on 485 consecutive infirmary admissions during a period of 14 months by inoculating the throat swab on the surface of a sheep blood agar plate. ASO titers were determined for the acute and convalescent phases of 95% of the 321 untreated illnesses associated with negative cultures. A rise in ASO titer occurred in 3.6% of these illnesses. ASO titers were also determined on pairs of sera for 51 of 53 untreated febrile illnesses associated with negative streptococcal cultures in 1962 and a rise in ASO titer occurred for only one of these illnesses (2%). This simple method for pharyngeal cultures is adequate and accurate as a laboratory aid to the practicing physician for the diagnosis of streptococcal pharyngitis in normal children. Bacitracin sensitivity showed an excellent correlation with Group A streptococci. Studies of duplicate swabs indicated that overnight storage of a dry swab at room or refrigerator temperature was associated with the recovery of more than 10 colonies of hemolytic streptococci from 80% to 88% of the swabs whose duplicates had more than 50 colonies.