Comparison of two commercial platforms and a laboratory developed test for detection of SARS-CoV-2 RNA

Mitigation of the ongoing COVID-19 pandemic requires reliable and accessible laboratory diagnostic services. We evaluated the performance of one LDT and two commercial tests, cobas® SARS-CoV-2 (Roche) and Amplidiag® COVID-19 (Mobidiag), for the detection of SARS-CoV-2 RNA in respiratory specimens. 183 specimens collected from suspected COVID-19 patients were studied with all three methods to compare their performance. In relation to the reference standard, which was established as the result obtained by two of the three studied methods, the positive percent agreement (PPA) was highest for cobas® test (100%), followed by Amplidiag® test and the LDT (98.9%). The negative percent agreement (NPA) was lowest for cobas® test (89.4%), followed by Amplidiag® test (98.8%) and the highest value was obtained for LDT (100%). The dilution series conducted for specimens, however, suggests significantly higher sensitivity for the cobas® assay in comparison with the other two assays and the low NPA value may be due to the same reason. In general, all tested assays performed adequately. Both the time from sample to result and hands-on time per sample were shortest for cobas® test. Clinical laboratories need to be prepared for uninterrupted high-throughput testing during the coming months in mitigation of the pandemic. To secure that, it is of critical importance for clinical laboratories to maintain several simultaneous platforms in their SARS-CoV-2 nucleic acid testing.