The need for control of throat streptococcal cultures in general practice.

During recent years, it has become more and more common among general practitioners and pediatricians to inoculate and read agar plates for diagnosis of beta-hemolytic streptococci so that an accurate etiological diagnosis in cases of suspected tonsillitis can be made. As a control of the diagnostic quality, "unknown" streptococcal strains were distributed from the bacteriological laboratory to the practitioners performing this type of diagnostic procedure. The results show that the ability to correctly classify these strains varied greatly. Technical problems such as inadequate temperature control of relatively simple incubators were also found. Continuous education and information on beta-hemolytic streptococcal diagnostic procedures are important to ensure sufficient quality.