Published in:
Open Access 01-12-2023 | SARS-CoV-2 | Research
Assessing the comparability of cycle threshold values derived from five external quality assessment rounds for omicron nucleic acid testing
Published in: Virology Journal | Issue 1/2023
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Background
A variety of open-system real-time reverse transcriptase polymerase chain reaction (RT-PCR) assays for several acute respiratory syndrome coronavirus 2 are currently in use. This study aimed to ensure the quality of omicron nucleic acid testing and to assess the comparability of cycle threshold (Ct) values derived from RT-PCR.
Methods
Five external quality assessment (EQA) rounds using the omicron virus-like particles were organized between February 2022 and June 2022.
Results
A total of 1401 qualitative EQA reports have been collected. The overall positive percentage agreement was 99.72%, the negative percentage agreement was 99.75%, and the percent agreement was 99.73%. This study observed a significant variance in Ct values derived from different test systems. There was a wide heterogeneity in PCR efficiency among different RT-PCR kits and inter-laboratories.
Conclusion
There was strong concordance among laboratories performing qualitative omicron nucleic acid testing. Ct values from qualitative RT-PCR tests should not be used for clinical or epidemiological decision-making to avoid the potential for misinterpretation of the results.