Streptococcal pharyngitis. Evaluation of a new diagnostic kit for clinic and office use.

One hundred sixty-eight children with upper respiratory infections were screened for beta-hemolytic streptococcal pharyngitis. A recently developed throat culture kit was processed in comparison with the conventional blood agar plate using a duplicate swab technique. Kits and plates were examined independently. Three individuals with no previous bacteriologic experience were allowed to interpret results of the culture kit after receiving instructions for approximately 15 minutes on three consecutive days. The interpretations of two of these individuals approached 95% accuracy, and those of the third individual surpassed this rate. The kit appears to be at least equal to the conventional blood agar plate in supporting the growth of beta-hemolytic streptococci. Moreover, its selective nature allows the nontechnical office staff to interpret results of the cultures promptly and accurately with a minimum of instruction.