Swab-Free Transport as an Optimized Preanalytical Workflow for SARS-CoV-2 Amplification.

Abstract

IntroductionEfficient detection of SARS-CoV-2 will continue to be an invaluable tool for pandemic control. Current instructions specify that the collection swab should be transported within its collection media to the laboratory. Developing a process whereby this swab is removed before transport to the lab would allow for improved automation and decreased manual manipulation of samples.MethodsA proof of principle approach was taken by eluting viral particles from flocked swabs into collection buffer with and without a mucus background. Paired swab-free and swab-containing samples were transported to the laboratory and evaluated for SARS-CoV-2 (n = 28) or RNaseP (n = 6). SARS-CoV-2 amplification was performed using the Hologic Panther Fusion Aptima and RT-PCR assays.ResultsSARS-CoV-2 was detected in all proof of principle samples with Ct values indicative of dilution. The rare exception was for a few samples where the dilution pushed the viral load below the LOD. Paired samples were 100% concordant for SARS-CoV-2 and RNaseP detection.ConclusionDiscarding the swab after inoculating the transport buffer is an appropriate pre-analytical modification. Adopting this approach can save up to 1 minute/sample. For labs processing more than 500 samples/day this equates to one full time equivalent shift/day.