Accuracy of an antigen-detecting SARS-CoV-2 assay with self- and provider-collected specimens interpreted visually and with BD Veritor™ Plus analyzer.

Background: SARS-CoV-2 rapid antigen tests (RATs) are in high demand for reducing the spread of SARS-CoV-2. Reduced involvement from health care professionals (HCPs) for collection and interpretation could significantly foster the wide-spread implementation of RATs, but data evaluating RATs, when used by lay people, is limited. Objective: To valuate agreement between BD Veritor test results for self- and HCP-collected specimens, and visually- and analyzer-interpreted results. Methods: Individuals with onset of COVID-19 symptoms within five days of enrollment had three nasal swabs collected; one self-collected and the other two HCP-collected. One HCP-collected swab was stored for future testing while the order of the other two (self and HCP) was randomized before testing. with the BD Veritor System for Rapid Detection of SARS-CoV-2. Results were first assessed visually, followed by interpretation with the analyzer. Results: When self-collection was compared to HCP collection for SARS-CoV-2 detection, interpretation by analyzer resulted in positive percent agreement (PPA) of 94.7% (95% CI 82.7, 98.5) and negative percent agreement (NPA) of 99.0% (95% CI 97.5, 99.6). When visual interpretation was compared to analyzer-read results, collection by HCPs had a PPA of 97.4% (95% CI 86.5, 99.5) and NPA of 99.8% (95% CI 98.6, 100.0) while self-collection resulted in PPA of 94.9% (95% CI 83.1, 98.6) and NPA of 99.8% (95% CI 98.6, 100). Conclusions: Similar PPA and NPA were observed for self- and HCP-collected specimens as well as visually- and analyzer-interpreted tests. The equivalence in performance supports the use of expanded collection and testing methods.

Concussion in Non-athletes: Assessment of Cognition and Symptomatology (CONTACTS) study protocol - an exploratory cohort study investigating the utility of sports concussion assessment tools and salivary microRNAs to diagnose concussion in NHS patients.

INTRODUCTION: Concussion is a complex pathophysiological process with a wide range of non-specific signs and symptoms. There are currently no objective diagnostic tests to identify concussion, and diagnosis relies solely on history and examination. Recent research has identified a unique panel of microRNAs (miRNAs) that distinguish between concussed and non-concussed rugby players. This study aims to assess the diagnostic utility of salivary miRNAs in concussion for a sample of UK National Health Service patients and whether well-established sports-related concussion (SRC) assessment tools may be translated into the emergency department (ED). METHODS AND ANALYSIS: Concussion in Non-athletes: Assessment of Cognition and Symptomatology is a single-centre, prospective, two-phase cohort study. The concussed cohort will consist of participants with maxillofacial trauma and concurrent concussion. The control cohort will consist of participants with isolated limb trauma and no evidence of concussion. Participants will be recruited in the ED and saliva samples will be taken to identify the presence of miRNAs. The SRC assessments being investigated include the Sports Concussion Assessment Test, Fifth Edition (SCAT5), the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) and the ImPACT Quick. Follow-up will be at 24-48 hours in-hospital and remotely via telephone and email at 14 days and 6 months. ETHICS AND DISSEMINATION: Ethical approval was granted in February 2021 by the West Midlands Coventry & Warwickshire Research Ethics Committee (ref 20/WM/0299). The investigators intend to submit their study findings for publication in peer-reviewed journals and to disseminate study findings via presentation at academic meetings. The results will also form part of a doctorate thesis, registered at the University of Birmingham.

Large-Scale SARS-CoV-2 Antigen Testing With Real-World Specimens.

Real-world data are needed to establish SARS-CoV-2 rapid antigen testing (RAT) as an effective and reliable approach for SARS-CoV-2 screening. This study included 1,952,931 individuals who provided upper respiratory specimens during SARS-CoV-2 screening at CityMD urgent care locations in the New York metropolitan area from October 2020 to March 2021. Positive and negative results, as determined by the BD Veritor™ System for Rapid Detection of SARS-CoV-2 antigen (Veritor), were obtained for all individuals, with reflex reverse transcriptase-polymerase chain reaction (RT-PCR) testing performed on a case-by-case basis, per standard of care. Using verification bias adjustment, two alternative model assumptions were utilized for RAT results with missing reflex RT-PCR results. The worst antigen diagnostic performance estimates asserted that missing RT-PCR results would show a distribution similar to those RT-PCR results actually obtained, based on symptom category. The best antigen diagnostic performance estimates asserted that individuals without RT-PCR results had a clinical presentation consistent with RAT results, and, therefore, missing RT-PCR results would agree with RAT results. For patients with symptoms or high-risk exposure, 25.3% (n = 86,811/343,253) of RAT results were positive; vs. 3.4% (n = 53,046/1,559,733) positive for asymptomatic individuals without high-risk exposure. Reflex RT-PCR results were obtained from 46.3% (n = 158,836/343,253) and 13.8% (n = 215,708/1,559,733) of symptomatic and asymptomatic individuals, respectively. RT-PCR confirmed 94.4% (4,265/4,518) of positive and 90.6% (139,759/154,318) of negative RAT results in symptomatic individuals; and confirmed 83.4% (6,693/8,024) of positive and 95.3% (197,955/207,684) of negative RAT results in asymptomatic individuals. Applied assumptions for missing reflex RT-PCR results led to worst performance sensitivity estimates of 77.2 and 38.5% in the symptomatic and asymptomatic populations, respectively; assumptions for best performance estimates led to sensitivity values of 85.6 and 84.2%, respectively. Specificity values, regardless of assumptions or symptom category, ranged from 97.9-99.9%. At 10% SARS-CoV-2 prevalence, RAT positive predictive value was 86.9 and 99.0% for worst and best performance estimates across the total population, respectively; negative predictive values were >95% regardless of the applied assumption. Veritor test performance was consistent with that listed in the manufacturer instructions for use for symptomatic individuals. Real-world evidence should be gathered on RATs to support their efficacy as SARS-CoV-2 persists.

Factors that Influence the Reported Sensitivity of Rapid Antigen Testing for SARS-CoV-2.

Tests that detect the presence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antigen in clinical specimens from the upper respiratory tract can provide a rapid means of coronavirus disease 2019 (COVID-19) diagnosis and help identify individuals who may be infectious and should isolate to prevent SARS-CoV-2 transmission. This systematic review assesses the diagnostic accuracy of SARS-CoV-2 antigen detection in COVID-19 symptomatic and asymptomatic individuals compared to quantitative reverse transcription polymerase chain reaction (RT-qPCR) and summarizes antigen test sensitivity using meta-regression. In total, 83 studies were included that compared SARS-CoV-2 rapid antigen-based lateral flow testing (RALFT) to RT-qPCR for SARS-CoV-2. Generally, the quality of the evaluated studies was inconsistent; nevertheless, the overall sensitivity for RALFT was determined to be 75.0% (95% confidence interval: 71.0-78.0). Additionally, RALFT sensitivity was found to be higher for symptomatic vs. asymptomatic individuals and was higher for a symptomatic population within 7 days from symptom onset compared to a population with extended days of symptoms. Viral load was found to be the most important factor for determining SARS-CoV-2 antigen test sensitivity. Other design factors, such as specimen storage and anatomical collection type, also affect the performance of RALFT. RALFT and RT-qPCR testing both achieve high sensitivity when compared to SARS-CoV-2 viral culture.