A Nationwide Review of the Utilization of Rapid Antigen Testing for Group A Streptococcus

Background Group A streptococcus (GAS) is the leading cause of bacterial pharyngitis in children and adolescents, accounting for up to 40% of all cases of pharyngitis in children aged 5 to 15 years. The global incidence of GAS pharyngitis and invasive GAS infections has increased over the past few years. In Malta, Mater Dei Hospital houses the only dedicated pediatric emergency department and is also the only health care facility offering free GAS rapid antigen detection tests (RADTs). As per hospital protocol, the Centor criteria are used to assess the likelihood of GAS pharyngitis. Method Staff members in the Pediatric Emergency Department at Mater Dei Hospital in Malta were asked to document all patients who needed a GAS RADT between June 2024 and January 2025. Data were then collected retrospectively from patient records, including demographics, clinical features, antibiotic choice, Centor scores, and RADT results. Analysis was conducted using summative and descriptive statistics, and chi-squared tests to assess associations between Centor score, RADT results, and age groups. A p-value of <0.05 was deemed statistically significant. Results A total of 103 patients were included, with a slight male preponderance (55%, N=57). Documentation of Centor criteria was poor, with no documentation in 87% (N=90) of cases. No confirmatory bacterial swabs were taken following a positive rapid antigen swab. All patients with a positive test result received antibiotics, with 88% (N=23) receiving a 10-day course of co-amoxiclav. A positive result was more likely in children over three years of age. Conclusion Although RADTs for GAS are readily available for use and positive results prompt appropriate antibiotic prescribing, this study highlights that there are ongoing areas for improvement in the application of clinical criteria, indicating the need for testing and in antimicrobial stewardship. The overuse of RADT and the prescription of antibiotics for children whose RADT is negative emphasize the need for better documentation of the Centor score, improved adherence to the testing algorithm (including Centor score), and the use of culture confirmation for patients with a high clinical suspicion of GAS pharyngitis in spite of negative RADT.