Comparison between Nasal and Nasopharyngeal Swabs for SARS-CoV-2 Rapid Antigen Detection in an Asymptomatic Population, and Direct Confirmation by RT-PCR from the Residual Buffer

• DOI: 10.1128/spectrum.02455-21
• Publication Date: 2022-02-16T15:32:19Z
• Authors: Glenn Patriquin; Jason J. LeBlanc; Catherine Williams; Todd F. Hatchette; John Ross; Lisa Barrett; Ross Davidson
• Keywords: Contact tracing

Containment measures employed during the COVID-19 pandemic included prompt recognition of cases, isolation, and contact tracing. Bilateral nasal (NA) swabs applied to a commercial antigen-based rapid diagnostic test (Ag-RDT) offer simpler more comfortable alternative nasopharyngeal (NP) collection; however, little is known about sensitivity this method in an asymptomatic population. Participants community-based testing sites were screened for SARS-CoV-2 using Ag-RDT with NP sampling. Positive individuals returned confirmatory molecular consented repeating bilateral NA swab comparison. Residual buffer (RTB) from Ag-RDTs was subjected real-time reverse transcription-PCR (RT-PCR). Of 123,617 individuals, 197 Ag-RDT-positive participants included, 175 confirmed positive by RT-PCR. these 154 identified collection Ag-RDT, 88.0% compared collection. Stratifying results RT-PCR cycle threshold demonstrated that varied based on (CT) value paired sample. RTB collections resulted 100.0% 98.7% sensitivity, respectively. provide adequate use most sensitive specimens high viral loads. With streamlined approach possible without recollection or strategies. IMPORTANCE Nasal swabbing (COVID-19) comes many benefits but slightly less than traditional swabbing; lab-based could be performed directly residual either sample type.