Comparison of the Accula SARS-CoV-2 Test with a Laboratory-Developed Assay for Detection of SARS-CoV-2 RNA in Clinical Nasopharyngeal Specimens

Abstract

Background: Several point-of-care (POC) molecular tests have received emergency use authorization (EUA) from the Food and Drug Administration (FDA) for diagnosis of SARS-CoV-2. The test performance characteristics of the Accula (Mesa Biotech) SARS-CoV-2 POC test need to be evaluated to inform its optimal use. Objectives: The aim of this study was to assess test performance of the Accula SARS-CoV-2 test. Study design: The performance of the Accula test was assessed by comparing results of 100 nasopharyngeal swab samples previously characterized by the Stanford Health Care EUA laboratory-developed test (SHC-LDT) targeting the envelope (E) gene. Assay concordance was assessed by overall percent agreement, positive percent agreement (PPA), negative percent agreement (NPA), and Cohen's kappa coefficient. Results: Overall percent agreement between the assays was 84.0% (95% confidence interval [CI] 75.3 to 90.6%), PPA was 68.0% (95% CI 53.3 to 80.5%) and the kappa coefficient was 0.68 (95% CI 0.54 to 0.82). Sixteen specimens detected by the SHC-LDT were not detected by the Accula test, and showed low viral load burden with a median cycle threshold value of 37.7. NPA was 100% (95% CI 94.2 to 100%). Conclusion: Compared to the SHC-LDT, the Accula SARS-CoV-2 test showed excellent negative agreement. However, positive agreement was low for samples with low viral load. The false negative rate of the Accula POC test calls for a more thorough evaluation of POC test performance characteristics in clinical settings, and for confirmatory testing in individuals with moderate to high pre-test probability of SARS-CoV-2 who test negative on Accula.

Evaluation of the Cue Health point-of-care COVID-19 (SARS-CoV-2 nucleic acid amplification) test at a community drive through collection center

“…These locations may not have access to central laboratory equipment or personnel and have a need to triage or counsel the patient according to the results obtained, thus making a point-of-care test the optimal solution. The evaluations of several rapid or point-of-care test solutions for molecular detection of SARS-CoV-2 have been recently published ( Zhen et al, 2020 , Basu et al, 2020 , Wolters et al, 2020 , Creager et al, 2020 , Hogan et al, 2020 ), however these studies have used mostly residual samples submitted for central laboratory testing and the testing was performed by in a controlled laboratory environment.…”

Recent biotechnological advances as potential intervention strategies against COVID-19

“…Early months of the pandemic, active case identification and surveillance was performed by Lab-based molecular RT-PCR tests, using several pair of primers from different sequences of SARS-CoV-2, depending on the country of origin of the test (WHO 2020 ). One major challenge for these tests was the time for results return; although currently commercially available kits, such as COVID-19 HomeTest Kit from Carbon Health or Roche Cepheid EXpert Xpress, offer results as early as 3 h (Hogan et al 2020 ). Over the last decades, biotechnological advances in molecular biology have made possible the development of rapid tests such as loop-mediated isothermal amplification (LAMP), following an initial RT-amplification step.…”

“…A promising commercial LAMP-based rapid detection test, ID NOWTM COVID Test developed by Abbot’s Binaxx, obtained emergency use authorization by the USA-FDA in July given it rapid result returns of as early as 5 min for positive result and 13 for negative results (Abbot 2020 ). A recent study by Hogan et al ( 2020 ) showed that ID NOW test has similar sensitivity and specificity of the results as Lab-based RT-PCR tests but only for patients with high viral load on mucus samples; nonetheless, the authors argue that virus could still be transmitted from undetected infected individuals. An alternative approach under study are Aptamers, a pool of oligonucleotides, or even small peptide molecules, and first reported in 1990 (O’Sullivan 2002 ).…”

Portable RT-PCR System: a Rapid and Scalable Diagnostic Tool for COVID-19 Testing

“…Thus, an affordable testing system for COVID-19 that is rapid, portable, and easily accessible in remote and low-resourced environments can significantly mitigate the spread of the virus in many communities. (10). The BD Veritor system that provides a rapid detection of SARS-CoV-2 nucleocapsid antigen was compared to a RT-PCR and demonstrated PPA that ranges between 81.8 -87.5% (11).…”