Frontiers in Public Health (Jan 2022)

Evaluation of Rapid Antigen Tests Using Nasal Samples to Diagnose SARS-CoV-2 in Symptomatic Patients

  • Manaf Alqahtani,
  • Manaf Alqahtani,
  • Manaf Alqahtani,
  • Abdulkarim Abdulrahman,
  • Abdulkarim Abdulrahman,
  • Fathi Mustafa,
  • Fathi Mustafa,
  • Abdulla I. Alawadhi,
  • Abdulla I. Alawadhi,
  • Batool Alalawi,
  • Saad I. Mallah

DOI
https://doi.org/10.3389/fpubh.2021.728969
Journal volume & issue
Vol. 9

Abstract

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IntroductionThe best way to mitigate an outbreak besides mass vaccination is via early detection and isolation of infected cases. As such, a rapid, cost-effective test for the early detection of COVID-19 is required.MethodsThe study included 4,183 mildly symptomatic patients. A nasal and nasopharyngeal sample obtained from each patient was analyzed to determine the diagnostic ability of the rapid antigen detection test (RADT, nasal swab) in comparison with the current gold-standard (RT-PCR, nasopharyngeal swab).ResultsThe calculated sensitivity and specificity of the RADT was 82.1 and 99.1%, respectively. Kappa's coefficient of agreement between the RADT and RT-PCR was 0.859 (p < 0.001). Stratified analysis showed that the sensitivity of the RADT improved significantly when lowering the cut-off RT-PCR Ct value to 24.ConclusionOur study's results support the potential use of nasal swab RADT as a screening tool in mildly symptomatic patients, especially in patients with higher viral loads.

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