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

Mannonen, Laura; Kallio-Kokko, Hannimari; Loginov, Raisa; Jääskeläinen, Anu; Jokela, Pia; Antikainen, Jenni; Väre, Paula; Kekäläinen, Eliisa; Kurkela, Satu; Jarva, Hanna; Lappalainen, Maija

Mitigation of the ongoing COVID-19 pandemic requires reliable and accessible laboratory diagnostic services. In this study, the performance of one laboratory developed test (LDT) and two commercial tests, cobas SARS-CoV-2 (Roche) and Amplidiag COVID-19 (Mobidiag) were evaluated 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 the cobas test (100%), followed by the Amplidiag test and the LDT (98.9%). The negative percent agreement (NPA) was lowest for the cobas test (89.4%), followed by the Amplidiag test (98.8%) and the highest value was obtained for the LDT (100%). The dilution series of positive 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. 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.