1. Evaluation of two RT-PCR screening assays for identifying SARS-CoV-2 variants
- Author
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Jacques Izopet, Sébastien Lhomme, Marion Migueres, Chloé Dimeglio, N. Ranger, Jean-Michel Mansuy, Florence Nicot, J. Latour, Marcel Miedougé, Martine Dubois, and Pauline Trémeaux
- Subjects
Variants of concern (VOC) ,TaqPath ,Lineage (genetic) ,Coronavirus disease 2019 (COVID-19) ,SARS-CoV-2 ,Reverse Transcriptase Polymerase Chain Reaction ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,RT-PCR ,COVID-19 ,ID triplex ,Biology ,Genome sequencing ,Virology ,DNA sequencing ,Virus ,Article ,Infectious Diseases ,Real-time polymerase chain reaction ,Multiplex polymerase chain reaction ,Humans ,Gene ,Multiplex Polymerase Chain Reaction - Abstract
Background The recent emergence of new SARS CoV-2 variants (variants of concern, VOC) that spread rapidly and may lead to immune escape has emphasized the urgent need to monitor and control their spread. Methods We analyzed 2018 SARS-CoV-2 positive specimens collected between February 9 and March 22, 2021 using the Thermofisher® TaqPath™ COVID-19 CE-IVD RT-PCR kit (TaqPath) and the ID solutions® ID™ SARS-CoV-2/UK/SA Variant Triplex RT-PCR (ID triplex) assay to screen for VOCs. Results The ID triplex assay identified 62.8% of them as VOCs: 61.8% B.1.1.7 and 0.9% B.1.351/P.1. The agreement between the ID triplex results for B.1.1.7 and the TaqPath S gene target failure (SGTF)/ S gene target late detection (SGTL) profile for this variant agreed very well (k = 0.86). A low virus load was the main cause of discrepancies. Sequencing discordant results with both assays indicated that the TaqPath assay detected the B.1.1.7 lineage slightly better. Both assays suggested that the virus loads of B.1.1.7 variants were significantly higher than those of non-B.1.1.7 strains. Only 10/20 B1.351/P.1 strains detected with the ID triplex assay were confirmed by sequencing. Conclusions We conclude that the SGTF/SGTL profiles identified using the TaqPath assay and ID triplex results are suitable for detecting the B.1.1.7 lineage. The ID triplex assay, which rapidly determines all three current VOCs simultaneously, could be a valuable tool for limiting virus spread by supporting contact-tracing and isolation.
- Published
- 2021