Related Experiment Video
Updated: Aug 10, 2025
Rapid Antimicrobial Susceptibility Testing by Stimulated Raman Scattering Imaging of Deuterium Incorporation in a Single Bacterium
Published on: February 14, 2022
Diagnosis of group A streptococcal pharyngitis in the paediatric emergency department using a fluorescence-based
Ali J Alhaddad1, Salma Aljaroodi1, Omar M Alkhasawneh2
1Department of Microbiology, College of Medicine, Imam Abdulrahman Bin Faisal University (IAU), Dammam, Saudi Arabia.
Insights
A new fluorescence immunoassay rapid antigen diagnostic test (FIA-RADT) accurately diagnoses group A streptococcal pharyngitis in children. This point-of-care test can significantly reduce unnecessary antibiotic prescriptions.
Area of Science:
- Pediatric Emergency Medicine
- Infectious Diseases
- Diagnostic Accuracy
Background:
- Rapid antigen diagnostic tests (RADTs) for group A streptococcal (GAS) pharyngitis exhibit high specificity but variable sensitivity.
- Local data on the diagnostic performance of novel fluorescence immunoassay RADTs (FIA-RADTs) and their impact on antibiotic prescribing patterns are lacking.
Purpose of the Study:
- To assess the accuracy of FIA-RADTs in diagnosing GAS pharyngitis in children presenting with pharyngitis.
- To estimate the effect of FIA-RADTs as a point-of-care test (POCT) on antibiotic prescription rates in a pediatric emergency department.
Main Methods:
- A prospective study enrolled 246 children aged 3-14 years with pharyngitis.
- Throat swabs were analyzed using both FIA-RADTs and throat culture; conventional PCR was used for discordant results.
Main Results:
- FIA-RADTs demonstrated high diagnostic accuracy: 95.6% sensitivity, 96.8% specificity, 94.6% positive predictive value, and 97.4% negative predictive value.
- Implementation of FIA-RADTs as POCT could reduce antibiotic prescriptions from 65.9% to 37.4%.
- FIA-RADTs significantly decreased antibiotic prescribing rates for patients with clinical scores of 2 and 3 from 48.8%/60.6% to 9.5%/31.9% respectively.
Conclusions:
- The FIA-RADT is a reliable, prompt, and user-friendly diagnostic tool for GAS pharyngitis in pediatric settings.
- This test can aid in reducing antibiotic overprescription, particularly in low-risk children identified by clinical scoring.
Abstract:
Introduction. Using rapid antigen diagnostic tests (RADTs) in clinical practice has shown excellent specificity but often has diminished sensitivity.Gap Statement. Local data for evaluating the diagnostic performance of a new fluorescence-based RADT and its influence on the antibiotic prescription rate are not available.Aim. To evaluate the accuracy of fluorescent immunoassay (FIA)-RADTs for diagnosing group A streptococcal (GAS) pharyngitis among children and its estimated effect as a point of care test (POCT) on the antibiotic prescription rate at the paediatric emergency department.Methodology. A prospective study was conducted, comprising children 3 to 14 years old presenting with pharyngitis. Throat swab culture and FIA-RADTs were performed on all samples. Conventional PCR was performed on the discordant samples.Results. A total of 246 children were included in this study. The sensitivity, specificity, and positive and negative predictive values of the FIA-RADT, based on culture results and PCR detection combined, were 95.6, 96.8, 94.6 and 97.4 %, respectively. Antibiotics have been prescribed to 162 (65.9 %) children; however, if FIA-RADTs had been added in the clinical practice as a POCT, only 92 (37.4 %) children would have received antibiotics in total. Additionally, implementation of FIA-RADTs would significantly reduce the antibiotic prescription rate from 48.8 and 60.6 % to 9.5 and 31.9 % among patients with clinical scores of 2 and 3, respectively.Conclusion. The new FIA-RADT is simple, prompt and reliable. It is helpful in clinical settings and may be used to reduce antibiotic overprescription, especially for children who have a low risk for GAS pharyngitis, according to the clinical score.
