Comparison of a Point-of-Care Assay and a High-Complexity Assay for Detection of SARS-CoV-2 RNA.

Abstract

Numerous nucleic acid amplification assays utilizing different target genes of the SARS-CoV-2 genome have received emergency use authorization (EUA) by the United States Food and Drug Administration (FDA). Limited data are available comparing the test performance characteristics of these assays.A diagnostic comparison study was performed to evaluate the performance of the Cepheid Xpert Xpress SARS-CoV-2 assay compared to the Hologic Panther Fusion SARS-CoV-2 assay using clinical nasopharyngeal specimens. Agreement between the two assays was assessed by overall, positive, and negative percent agreement and Cohen's kappa coefficient.A total of 104 (54 positive and 50 negative) clinical nasopharyngeal samples were tested by both assays. Using the Panther Fusion as a reference standard, the Xpert demonstrated an overall agreement of 99.0% (95% confidence interval (CI): 94.8 - 100), positive percent agreement of 98.1% (95% CI: 90.1 - 100), and a negative percent agreement of 100% (95% CI: 94.2 - 100). The kappa coefficient was 0.98 (95% CI: 0.94 - 1.0). One sample positive by the Panther Fusion with a cycle threshold (Ct) of 38.6 was found to be reproducibly negative by the Xpert assay.The Cepheid Xpert Xpress SARS-CoV-2 assay provides test performance comparable to the Hologic Panther Fusion SARS-CoV-2 assay while offering laboratories rapid, on-demand testing capacity.

View details for DOI 10.1093/jalm/jfaa135

View details for PubMedID 32761092