ABSTRACT
Reveal colour strep A, antigen detection kit was compared with aerobic and anaerobic cultures for detection of Group A beta hemolytic streptococci [GAHS] in oropharyngeal swabs obtained from 50 patients with acute pharyngitis and/or acute tonsillitis. Quantitation of Streptococcal colonies on the plate was correlated with the results of reveal colour strep A and with the clinical symptoms of the patients. Anaerobic Gas Pak Culture produced the highest recovery rater. Aerobic incubation also gave a very acceptable result. The Reveal colour strep A kit detected 78% of culture positive swabs with a sensitivity of 82% compared to 85% and 84% for the anaerobic and aerobic cultivation respectively. Its specificity was 97% compared to 96% and 97% for the two culture methods. The predictive values of positive results were 95%, 96% and 91% while the predictive values of negative results were 89%, 87% and 88% for Reveal colour strep A, anaerobic and aerobic culture respectively. The results of Reveal colour strep A kit were found to be directly proportional to the number of CFU in the specimen and to the clinical manifestations. We concluded that Reveal colour strep A kit has the potential to provide rapid diagnosis of GAHS pharyngitis and thus facilitate the prompt initiation of appropriate antibiotic therapy. This test also has the potential to exclude GAHS pharyngitis rapidly and thereby preclude initiation of unnecessary antibiotic treatment. However, we recommended that if this test was negative, a backup throat culture is necessary and 2 oropharyngeal swabs from each patient must be obtained, one for culture and the other for antigen detection