A Laboratory Validation of Self-Collected Nasal Swab and Rhinoswab for the Detection of Sars-Cov-2

ABSTRACT

Intro In Australia, the main methods to diagnose COVID-19 are through rapid antigen tests (RATs) and through nucleic acid amplification testing (NAAT, including polymerase chain reaction) on healthcare worker (HCW)-collected combined nose/throat swabs. With self-collection widely used by the public for RATs, the aim of this study was to evaluate the performance of self-collected samples using commercial NAAT for SARS-CoV-2. Method(s) Consenting participants aged 14 years and older were provided with a self-collection pack containing instructions and either a FLOQSwab (Copan) or a Rhinoswab (Rhinomed). Participants collected their own nasal sample unsupervised prior to having a HCW-collected combined nose and throat swab taken for standard of care NAAT. Paired self-collected and HCW samples were tested on the cobas SARS-CoV-2 assay (Roche) and the Aptima SARS-CoV-2 assay (Hologic). Finding(s) We demonstrated comparable sensitivity, specificity, and agreement between self-collected nasal and Rhinoswab samples, compared to HCW- collected samples tested using the cobas SARS-CoV-2 and Aptima SARS-CoV-2 assays. In our study the clinical performance of self-collected specimens was comparable to HCW-collected samples, with both self-collect nasal and Rhinoswab samples resulting in 90-95% sensitivity, and in most cases >95% specificity. Discussion(s) Without the availability of samples for NAAT the ability to perform genomic testing is limited, reducing surveillance and public health investigations. We showed that genomic sequencing from self-collected samples can correctly identify the virus lineage and that the main determination of successful genomic testing is a high viral load rather than collection method. Conclusion(s) These data support self-collection as an accessible method for community testing for COVID-19 and introduces a novel collection device, the Rhinoswab as an alternative to the standard nasal swab. The testing method of self-collection can be expanded from the widely used RATs to NAAT and genomic testing which may inform the management and public health response to the COVID-19 pandemic.Copyright © 2023