Performance Evaluation of STANDARD F Strep A Ag FIA for Diagnosis of Group A Streptococcal Pharyngitis
- Author:
Seon A JO
1
;
Sang Hyuk MA
;
Seungjun LEE
;
Sunjoo KIM
Author Information
- Publication Type:Original Article
- From:Annals of Clinical Microbiology 2020;23(3):177-184
- CountryRepublic of Korea
-
Abstract:
Background:Pharyngitis is one of the most common conditions encountered in primary health care facilities. Accurate differentiation of group A streptococcus (GAS) infection from viral infection is difficult. The STANDARD F Strep A Ag FIA (SD BIOSENSOR, Korea) is a rapid antigen detection test (RADT) that has been recently developed for diagnosing GAS pharyngitis. In this study, we evaluated the diagnostic performance of the STANDARD F Strep A Ag FIA and compared the results between the RADT and conventional throat culture.
Methods:Throat swab samples were obtained from a total of 372 children presenting pharyngitis symptoms in five pediatric clinics in Changwon, Korea from July 2018 to October 2019. A comparative study between STANDARD F Strep A Ag FIA and Sofia Strep A FIA (Quidel, USA) was performed. Two throat swabs were taken simultaneously from each patient for RADT. The third throat swab was stored in a transport tube containing Stuart's transport medium for culture. Performance and kappa index of STANDARD F Strep A Ag FIA were evaluated.
Results:GAS infection was detected in 29.3% (109/372) patients, using the STANDARD F Strep A Ag FIA. The sensitivity, specificity, positive predictive value, and negative predictive value were 95.0%, 95.2%, 88.1%, and 98.1%, respectively. The STANDARD F Strep A Ag FIA showed an excellent concordance rate of 96.5% and a kappa value of 0.89 compared to Sofia Strep A FIA.
Conclusion:The STANDARD F Strep A Ag FIA demonstrated an excellent performance along with Sofia Strep A FIA for the diagnosis of GAS pharyngitis.
