Tiny swabs: nasal swabs integrated into tube caps facilitate large-scale self-collected SARS-CoV-2 testing

Abstract

The COVID-19 pandemic spurred the development of innovative solutions for specimen collection and molecular detection for large-scale community testing. Among these developments is the RHINOstic nasal swab, a plastic anterior nares swab built into the cap of a standard matrix tube that facilitates automated processing of up to 96 specimens at a time. In a study of unsupervised self-collection utilizing these swabs, we demonstrate comparable analytic performance and shipping stability compared to traditional anterior nares swabs, as well as significant improvements in laboratory processing efficiency. The use of these swabs may allow laboratories to accommodate large numbers of sample collections during periods of high testing demand. Automation-friendly nasal swabs are an important tool for high-throughput processing of samples that may be adopted in response to future respiratory viral pandemics.

Keywords: respiratory pathogens; scaled testing; specimen collection.

Fig 1

Comparison of usability and analytical performance metrics between US Cotton #3 anterior nares swabs and RHINOstic swabs. (A) Boxplot of Rnase P Ct values from the 69 US Cotton and RHINOstic swabs. (B) Dotplot comparison of RNase P Ct values. (C) Barplot comparison of participants’ self-reported confidence that they had collected the swab correctly. (D) Barplot comparison of participants’ self-reported discomfort levels using the swab for collection. (E) Barplot distribution of participants’ self-reported overall ease handling the RHINOstic swab. (F) Barplot distribution of participants self-reported ease reading the eight-character barcode on the RHINOstic tube.

Fig 2

Performance of SARS-CoV-2 and RNase P assays during the winter (A) and summer (B) stability experiments.

Fig 3

Comparison of the weekly positivity rate for SARS-CoV-2 between our laboratory’s RHINOstic specimens and King County, Washington, beginning from deployment of RHINOstic swabs the week of 2021-08-22.

Fig 4

(A) Gantt chart demonstrating the average time to complete technician steps prior to heat inactivation of 96 samples, measured in minutes. Where the US Cotton swabs require an aliquoting step, which is done concurrently with the accessioning step (tubes are scanned and then aliquoted one at a time), the RHINOstic tubes do not require aliquoting and accessioning is done as a single process. (B) Comparison of specimens accessoned per technician per day between swab types as a measure of processing efficiency.