Abstract
Introduction : It is recommended that all negative rapid antigen tests for Group A streptococcus infection be conducted as back-up cultures.
Purpose : This study is intended to make a comparison of clinical manifestations and physical findings between patient and non-patient groups ; and to determine the effects on rapid strep test results if the same swab is used for both the culture and the rapid strep test.
Methods : We retrospectively studied the medical records of 480 cases where the rapid strep test was conducted in the outpatient pediatric department. The patient group consisted of those with positive laboratory cultures.
Results : The patient group was 124 cases. The patient group showed significantly high incidences of sore, or reddened throats, with a significantly small amount of tonsillar exudate.
 The sensitivity of the strep tests was 87.9% and their specificity was 100% on a culture test.
Conclusion : It is difficult to rule in or rule out the Group A streptococcus infection on the basis of the clinical manifestations and physical findings. By using the same swab for both culture and rapid strep test, the results of the latter were less affected, and so this was considered as a simple and effective diagnostic method.