Clinical Diagnostic Study of a Novel Injection Molded Swab for SARS-Cov-2 Testing

Tay, Joshua K.; Cross, Gail B.; Sun, Louisa; Chia, Alfred; Chee, Jeremy; Loh, Jerold; Lim, Zhen Yu; Ngiam, Nicholas; Khang, Wen Pang; Yeap, Stephanie; Goh, Han Lee; Siow, Chor Hiang; Loh, Woei Shyang; Loh, Kwok Seng; Lee, Chun Kiat; Yan, Benedict; Chow, Vincent T. K.; Wang, De Yun; Boey, Freddy; Wong, John E. L.; Allen, David M.

INTRODUCTION: The gold standard for COVID-19 diagnosis is currently a real-time reverse transcriptase polymerase chain reaction (RT-PCR) to detect SARS-CoV-2. This is most commonly performed on respiratory secretions obtained via a nasopharyngeal swab. Due to supply chain limitations and high demand worldwide because of the COVID-19 pandemic, access to commercial nasopharyngeal swabs has not been assured. 3D printing methods have been used to meet the shortfall. For longer-term considerations, 3D printing may not compare well with injection molding as a production method due to the challenging scalability and greater production costs of 3D printing. METHODS: To secure sufficient nasopharyngeal swab availability for our national healthcare system, we designed a novel injection molded nasopharyngeal swab (the IM2 swab). We performed a clinical diagnostic study comparing the IM2 swab to the Copan FLOQSwab. Forty patients with a known diagnosis of COVID-19 and 10 healthy controls were recruited. Paired nasopharyngeal swabs were obtained from the same nostril of each participant and tested for SARS-CoV-2 by RT-PCR. RESULTS: When compared to the Copan FLOQswab, results from the IM2 swab displayed excellent overall agreement and positive percent agreement of 96.0% and 94.9%, respectively. There was no significant difference in mean RT-PCR cycle threshold values for the ORF1ab (28.05 vs. 28.03, p = 0.97) and E-gene (29.72 vs. 29.37, p = 0.64) targets, respectively. We did not observe any significant adverse events and there was no significant difference in patient-reported pain. CONCLUSION: In summary, the IM2 nasopharyngeal swab is a clinically safe, highly accurate option to commercial nasopharyngeal swabs. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40121-020-00391-6.