Optimizing Pharyngitis Diagnosis: A Comparative Analysis of Rapid Antigen Detection Tests and Molecular Tests

Strategic Insights -

A team of researchers from the Laboratoire Hospitalier Universitaire de Bruxelles-Universitair Laboratorium Brussel (LHUB-ULB) in Brussels, Belgium, has published a new report on optimizing the diagnosis of pediatric group A streptococcus (GAS) pharyngitis. The study compared the sensitivity and specificity of rapid antigen detection tests (RADTs) and molecular tests with bacterial culture, the current gold standard. The research aimed to evaluate the effectiveness of these tests in guiding antibiotic use and minimizing unnecessary prescribing.

Key Takeaways:

  • The study collected 100 throat swabs from pediatric patients with suspected GAS pharyngitis and tested each sample using bacterial culture, RADT, and molecular test.
  • The OSOM Strep A Test demonstrated a sensitivity of 91% (73-97) and a specificity of 100% (95-100) when compared to bacterial culture.
  • The ID NOW Strep A 2 test showed a sensitivity of 87% (67-95) and a specificity of 94% (85-97) when compared to bacterial culture.
  • When the molecular test was used as the reference, both bacterial culture and the OSOM Strep A Test exhibited similar sensitivities (83% (64-93) and 80% (60-91), respectively), with high specificities (96% (89-98) and 99% (92-99)).
  • The guidelines analysis revealed different approaches to GAS diagnosis, with varying reliance on clinical scores, routine testing, or confirmatory culture.

Statistics:

  • 100 throat swabs were collected from pediatric patients with suspected GAS pharyngitis.
  • The study found that the OSOM Strep A Test had a sensitivity of 91% and a specificity of 100% when compared to bacterial culture.
  • The ID NOW Strep A 2 test had a sensitivity of 87% and a specificity of 94% when compared to bacterial culture.
  • The molecular test exhibited sensitivities of 83% (bacterial culture) and 80% (OSOM Strep A Test), with high specificities of 96% (bacterial culture) and 99% (OSOM Strep A Test).

Sources:

  • Optimizing the diagnosis of pediatric group A streptococcus (GAS) pharyngitis: A comparative analysis of rapid antigen detection tests, molecular tests and global guidelines. Diagnostic Microbiology and Infectious Disease, 2025;114(2):117124.
  • Elsevier Science Inc, Ste 800, 230 Park Ave, New York, NY 10169, USA.
  • Laboratoire Hospitalier Universitaire de Bruxelles-Universitair Laboratorium Brussel (LHUB-ULB), Brussels, Belgium.
  • Kenza Benboujida, Dept. of Microbiology, LHUB-ULB, Brussels, Belgium.
  • Celestin Mairesse, Florence Adjavou, Jessica Vandenhoeck, Marc Hainaut, and Delphine Martiny, additional authors.