Rapid screening of SARS-CoV-2 infection: Good performance of nasopharyngeal and Nasal Mid-Turbinate swab for antigen detection among symptomatic and asymptomatic individuals

SICILIA, PAOLA; CASTRO, GONZALO; FANTILLI, ANABELLA CLARA; GIEROTTO, ROBERTINO; LÓPEZ, LAURA; BARBÁS, MARÍA GABRIELA; PISANO, MARÍA BELÉN; RÉ, VIVIANA ELIZABETH

PLOS ONE

PUBLIC LIBRARY SCIENCE

Año: 2022 vol. 17

1932-6203

Although the nasopharyngeal swab (NPS) is considered the gold standard for the diagnosisof the SARS-CoV-2 infection, the Nasal Mid-Turbinate swab (NMTS) is often used due to itshigher tolerance among patients. We compared the diagnostic performance of the NPS andthe NMTS for the Panbio? COVID-19 antigen-detecting rapid diagnostic test (Ag-RDT).Two hundred and forty-three individuals were swabbed three times by healthcare professionals: a NMTS and a NPS specimen for the Ag-RDT and an oropharyngeal swab for realtime RT-PCR. Forty-nine participants were RNA-SARS-CoV-2 positive by real time RTPCR: 45 and 40 were positive by the Ag-RDT with NPS and NMTS, respectively. The overallsensitivity and specificity were 91.8% (95% CI: 83.2?100.0) and 99.5% (95% CI: 98.2?100.0) for Ag-RDT with NPS, and 81.6% (95% CI: 69.8?93.5) and 100.0% (95% CI: 99.7?100.0) for the Ag-RDT with NMTS. The Cohen?s kappa index was 0.92 (95% CI: 0.85?0.98).Among asymptomatic individuals, the Ag-RDT with both sampling techniques showed ahigh sensitivity [100.0% (95% CI: 95.5?100.0) with NPS; 90.9% (95% CI: 69.4?100.0) withNMTS], while the performance of the test decreased in samples with Ct� 30 and in patientstested after the first 7 days from symptom onset. Although the NMTS yielded a lower sensitivity compared to NPS, it might be considered a reliable alternative, as it presents greateradherence among patients, enabling scaling of antigen testing strategies, particularly incountries with under-resourced health systems