Comparison of next generation diagnostic systems (NGDS) for the detection of SARS-CoV-2.

INTRODUCTION: The World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) a pandemic in March 2020. Initially, supply chain disruptions and increased demand for testing led to shortages of critical laboratory reagents and inadequate testing capacity. Thus, alternative means of biosample collection and testing were essential to overcome these obstacles and reduce viral transmission. This study aimed to 1) compare the sensitivity and specificity of Cepheid GeneXpert® IV and BioFire® FilmArray® 2.0 next generation detection systems to detect SARS-CoV-2, 2) evaluate the performance of both platforms using different biospecimen types, and 3) assess saline as an alternative to viral transport media (VTM) for sample collection. METHODS: A total of 1,080 specimens consisting of nasopharyngeal (NP) swabs in VTM, NP swabs in saline, nasal swabs, oropharyngeal (OP) swabs, and saliva were collected from 216 enrollees. Limit of detection (LoD) assays, NP VTM and NP saline concordance, and saliva testing were performed on the BioFire® FilmArray® 2.0 Respiratory Panel 2.1 and Cepheid GeneXpert® Xpress SARS-CoV-2/Flu/RSV assays. RESULTS: LoD and comparative testing demonstrated increased sensitivity with the Cepheid compared with the BioFire® in detecting SARS-CoV-2 in NP VTM and saline, nasal, and OP swabs. Conversely, saliva testing on the Cepheid showed statistically significant lower sensitivity compared to the BioFire® . Finally, NP swabs in saline showed no significant difference compared with NP swabs in VTM on both platforms. CONCLUSION: The Cepheid and BioFire® NGDS are viable options to address a variety of public health needs providing rapid and reliable, point-of-care testing using a variety of clinical matrices.

Evaluating sensitivity and specificity of the Biomeme Franklin™ three9 real-time PCR device and SARS-CoV-2 go-strips assay using clinical samples.

We evaluated the sensitivity and specificity of the Biomeme Franklin™ three9 Real-Time PCR Thermocycler and Biomeme SARS-CoV-2 Go-Strips in the detection of SARS-CoV-2. The Biomeme Franklin™ three9 platform is a portable, battery-operated system that could be used in remote settings. We assessed performance of the Biomeme SARS-CoV-2 detection system at a wide range of viral concentrations, examined cross-reactivity of the SARS-CoV-2 Go-Strips against several near-neighbor respiratory pathogens, and evaluated agreement against the BioFire® Respiratory Panel 2.1 in four clinical sample types. Our data indicate the Biomeme Go-Strips can reliably detect SARS-CoV-2 at a concentration of 4.2 × 103 copies/mL. No cross reactivity of the Go-Strips targets was detected against any of the tested near-neighbor respiratory pathogens. Cohen's kappa statistics ranged from 0.68 to 0.92 between results from the Biomeme SARS-CoV-2 Go-Strips and the BioFire® Respiratory Panel 2.1 in all the different sample types. Compared to the BioFire® Respiratory Panel 2.1, the Biomeme SARS-CoV-2 Go-Strips demonstrated statistically significantly lower sensitivity in 3 out of 5 sample types. Overall, our study demonstrates the Biomeme Franklin™ three9 used with the SARS-CoV-2 Go-Strips is an effective system for the detection of SARS-CoV-2 that could potentially be used in a remote or austere environment.

Functional stability of the TEG 6s hemostasis analyzer under stress.

BACKGROUND: Viscoelastic measurements of coagulation provide much needed information, including guidance for triage and insight into bleeding disorders. The current clinical standards for these devices are the thromboelastogram (TEG) 5000 and the rotational thromboelastometer (ROTEM) delta, but a new product, the TEG 6s, has recently come to market, designed to simplify the user experience, reduce the required blood volume, and conduct multiple assays simultaneously. This study compares the performance of these three devices and examines the resiliency of the TEG 6s under various stresses. METHODS: The variances of coagulation metrics obtained by the TEG 6s (prototype and production models), TEG 5000, and ROTEM delta were compared using manufacturers' reagents and citrate-collected blood from healthy donors. Variability between devices was examined, and their performances under various motion and temperature stresses were compared by placing one unit on a linear or orbital shaker, in the cold, or in the heat while a counterpart remained stationary at room temperature. RESULTS: Although most comparable parameters had low degrees of variance, there were small but significantly increased variances found in some ROTEM delta and TEG 5000 parameters versus comparable TEG 6s parameters. Orbital rotation of the TEG 6s had no effect on means of any parameter but resulted in increased variance of 2 parameters, but linear motion with sudden striking had no observed impact on results. Similarly, 7-day exposure to heat (45°C) or cold (4°C) only resulted in minor deviations within normal ranges of the TEG 6s. DISCUSSION: The TEG 6s provides several improvements over other coagulation analyzers: it is easier to use and robustly resilient against motion and temperature stresses. These features suggest that it may be capable of deployment not only in the clinical laboratory but also to a variety of austere settings. LEVEL OF EVIDENCE: Diagnostic test, level III.