Rapid Identification of Streptococcal Pharyngitis

Abstract

Acute pharyngitis is one commonest reasons for patients to visit the family physician, 80-90% of cases are caused by viruses particularly adenovirus. The most important bacterial cause is group A streptococcus, which is responsible for about 15% of all cases. Because of the time required to confirm the presence of group A streptococci using throat cultures many commercial antigen detection tests for the rapid identification of group A streptococci directly from throat swabs have been developed utilizing the latex agglutination principle and a result is available within 5 minutes. Objective: The purpose of this study was to determine the value of using rapid detection procedure (Reveal color strep A test, Murex) for group A streptococci directly from throat swabs. Material and Method: Data from 200 patients with sore throat attending one of the Public Medical Centers in Amman over 6 month period May 1998-January 1999. Both throat swabs and cultures were taken and throat swabs were subjected using (Reveal color strep A test) for rapid detection. The culture results were interpreted and reported by microbiologist. Data were analyzed by calculating the number of positives and negatives for both swabs and cultures, the specificity, sensitivity and predictive value were determined. Results: The usefulness of latex test was as follows: Sensitivity 87%, Specificity 98.2%, Predictive value positive 90%, and Predictive value negative 97.6%. Conclusion: Using tests for the rapid identification may help in establishing a policy for sore throat management in general practice by avoiding unnecessary cultures and antibiotic prescription