Comparison of the Roche cobas 6800 SARS-CoV-2 test and the Taiwan CDC protocol for the molecular diagnosis of COVID-19

Abstract

The current coronavirus disease 2019 (COVID-19) pandemic has caused significant challenges throughout the world and a rapid, reliable diagnostic test is in high demand. Real-time reverse transcription polymerase chain reaction (RT-PCR) was one of the most quickly established methods of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection and is considered to be the gold standard. In this report, we share our experience of using two different testing platforms: the cobas 6800 SARS-CoV-2 test, an automated system that was recently granted Emergency Use Authorization by the FDA, and a laboratory-developed test based on the protocol from the Taiwan Centers for Disease Control (CDC). There was an overall 96.2% agreement between the two platforms. However, the positive agreement between the two platforms was only 80.0%. We found 3 instances of discordance between the two systems and this emphasized the need for timely diagnosis with a reliable testing platform.

Keywords: Coronavirus; Molecular diagnostics; RNA extraction; RT-PCR; Viral load.

Fig. 1

Example of discordant cases between the two detection methods. (A) Amplification curves of the (a) E gene assay, (b) RdRp gene assay, and (c) N gene assay under the Taiwan CDC protocol for SARS-CoV-2 detection. (B) Results from the cobas 6800 SARS-CoV-2 test. The samples were collected from a suspected patient at day 1 and day 2.