Analytical performance of four rapid molecular testing for SARS-CoV-2

ABSTRACT

Various reagents and equipment for testing SARS-CoV-2 infections have been developed, particularly rapid molecular tests based on polymerase chain reaction (PCR).We evaluated the analytical performance of four rapid molecular tests for SARS-CoV-2. We used 56 nasopharyngeal swabs from patients with confirmed SARS-CoV-2 infection;36 diagnosed as positive by the Ampdirect™ 2019-nCoV Detection Kit (Shimadzu assay) were considered as true-positive samples.The sensitivity of Cobas® Liat SARS-CoV-2 and Flu A/B (Cobas) was the highest among the four molecular test kits. The limit of detection was 1.49 × 10−2 copies/µL (95% confidence interval [CI] 1.46×10−2−1.51 × 10−2 copies/µL) for Cobas;1.43 × 10−1 copies/µL (95% CI 8.01×10−3−2.78 × 10−1 copies/µL) for Xpert® Xpress SARS-CoV-2 test (Xpert);2.00 × 10−1 copies/µL (95% CI 1.95×10−1-2.05 × 10−1 copies/µL) for FilmArray Respiratory Panel v2.1 (FilmArray);and 3.33 × 10 copies/µL (95% CI 1.93 × 10–4.72×10 copies/µL) for Smart Gene® SARS-CoV-2 (Smart gene). Cobas also had a high sensitivity (100%) compared with Shimadzu assay. The sensitivities of Xpert, FilmArray, and Smart Gene were 97.2%, 97.2%, and 75.0%, respectively. The specificity of all tests was 100%.In conclusion, the four rapid SARS-CoV-2 molecular test kits have high specificity and sensitivity for detecting SARS-CoV-2. As they are easy to use, they could be a useful method for detecting SARS-CoV-2.