Development and Evaluation of a new Swiss Made SARS-CoV-2 antigen-detecting rapid test

Ducrest, P. J.

There is an urgent need in rapid diagnostic test (RDT) to detect antigen of SARS-CoV-2 to reduce the spread of COVID-19 outbreak. We have developed a rapid and simple point-of-care lateral flow immunoassay (LFIA) detecting nucleocapsid antigen of SARS-CoV-2 in 10 minutes. The aim of this study is to evaluate the diagnostic performance and analytical sensitivity of this RDT. RT-PCR positive nasopharyngeal swab samples (n=20) for SARS-CoV-2 and 40 negative control samples were studied. Analytical sensitivity was assessed using Gamma-irradiated SARS-CoV-2 and the limit of detection (LOD) was determined at 1.4 x 10^2 TCID50/ml. Overall, RDT diagnostic sensitivity was 90% (95% confidence interval [95%CI]: 67-98%) and specificity 98% (95% CI: 85-100%). The sensitivity was 100% (95% CI: 75-100%) when using only samples with a RT-PCR Cycle threshold lower than 30. This antigen RDT displays a high diagnostic accuracy for SARS-CoV-2 antigen detection in high COVID-19 prevalence settings. Its use could be considered in the absence of routine RT-PCR facilities such in low-income countries.