Evaluation of direct and rapid identification of group A streptococci from throat swabs by Culturette 10-Minute Group A Strep ID test kit.

The Culturette Brand 10-Minute Group A Strep ID test kit (Marion Scientific, Division of Marion Laboratories, Inc., Kansas City, Mo.) was evaluated for its sensitivity and specificity in identifying the group A streptococci directly from 96 throat swabs, against the conventional culture method and serological grouping test. Our results indicated that the rapid test kit and conventional method are 93.8% accurate; percent sensitivity and specificity of the rapid test was 80.6% and 100%, respectively. None of the false-positive observed in rapid test kits occurred with the heterogeneous microorganisms. More than 8 X 10(4) colony forming unit per swab was required for the positive latex agglutination of the test kit. Since the Culturette method is simple to perform and correctly identifies group A streptococcal antigen, and also required no special instruments, it appears to be applicable in hospital laboratories and outpatients clinics.