Clinical Evaluation and Utilization of Multiple Molecular In Vitro Diagnostic Assays for the Detection of SARS-CoV-2

Abstract

Objectives: To evaluate the clinical performance of 3 molecular assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods: We used 184 nasopharyngeal swab specimens to compare Abbott ID NOW COVID-19 (Abbott ID NOW), DiaSorin Molecular Simplexa COVID-19 Direct (DiaSorin Simplexa), and Roche cobas 6800 SARS-CoV-2 (Roche cobas) assays. In a separate analysis, 3 specimens (nasopharyngeal, oropharyngeal, and nasal) were collected from 182 unique patients presenting to the emergency department with suspicion of coronavirus disease 2019 and were tested utilizing Abbott ID NOW. To further characterize each assay, relative limits of detection were evaluated utilizing positive nasopharyngeal patient samples.

Results: The positive percent agreement was 91% (95% confidence interval [CI], 0.76-0.97) for Abbott ID NOW and 100% (95% CI, 0.90-1.00) for DiaSorin Simplexa and Roche cobas. The negative percent agreement was 100% (95% CI, 0.98-1.00) for all 3 assays. All swab types tested with the Abbott assay produced concordant results. Polymerase chain reaction assays had approximately 10 to 100 times lower limits of detection than Abbott ID NOW.

Conclusions: Based on these evaluations, a multiplatform testing approach is proposed, depending on patient population and assay sensitivity, to address testing needs during a public health emergency.

Keywords: Abbott ID NOW; COVID-19; Coronavirus; Molecular diagnostics; SARS-CoV-2.

Figure 1

Relative limits of detection of Abbott ID NOW, DiaSorin Simplexa, and Roche cobas using 10 nasopharyngeal swab–positive patient samples collected in universal viral transport medium. A 10-fold dilution series was made for each patient sample and tested on all 3 instruments until a negative result was obtained. For each patient series, results were normalized to the lowest detected dilution of Abbott ID NOW (1×) and the last detectable reaction below that dilution is indicated for each instrument. Each dot represents the lowest detected dilution for each patient relative to Abbott ID NOW. All data used for this analysis can be found in the supplemental dataset (all supplemental material is available at American Journal of Clinical Pathology online).