scholarly journals Evaluation of two rapid antigen tests to detect SARS-CoV-2 in a hospital setting

2021 ◽  
Author(s):  
Andreas Osterman ◽  
Hanna-Mari Baldauf ◽  
Marwa Eletreby ◽  
Jochen M. Wettengel ◽  
Suliman Q. Afridi ◽  
...  
Keyword(s):  
Point Of Care ◽  
False Negative ◽  
Hospital Setting ◽  
Outcome Data ◽  
Large Set ◽  
Antigen Test ◽  
University Hospitals ◽  
Clinical Sensitivity ◽  
Antigen Tests ◽  
The Impact

AbstractSuccessful containment strategies for the SARS-CoV-2 pandemic will depend on reliable diagnostic assays. Point-of-care antigen tests (POCT) may provide an alternative to time-consuming PCR tests to rapidly screen for acute infections on site. Here, we evaluated two SARS-CoV-2 antigen tests: the STANDARD™ F COVID-19 Ag FIA (FIA) and the SARS-CoV-2 Rapid Antigen Test (RAT). For diagnostic assessment, we used a large set of PCR-positive and PCR-negative respiratory swabs from asymptomatic and symptomatic patients and health care workers in the setting of two University Hospitals in Munich, Germany, i.e. emergency rooms, patient care units or employee test centers. For FIA, overall clinical sensitivity and specificity were 45.4% (n = 381) and 97.8% (n = 360), respectively, and for RAT, 50.3% (n = 445) and 97.7% (n = 386), respectively. For primary diagnosis of asymptomatic and symptomatic individuals, diagnostic sensitivities were 60.9% (FIA) (n = 189) and 64.5% (RAT) (n = 256). This questions these tests’ utility for the reliable detection of acute SARS-CoV-2-infected individuals, in particular in high-risk settings. We support the proposal that convincing high-quality outcome data on the impact of false-negative and false-positive antigen test results need to be obtained in a POCT setting. Moreover, the efficacy of alternative testing strategies to complement PCR assays must be evaluated by independent laboratories, prior to widespread implementation in national and international test strategies.

scholarly journals Clinical evaluation of rapid point of care antigen tests for diagnosis of SARS-CoV-2 infection

2021 ◽  
Author(s):  
Johannes G.M. Koeleman ◽  
Henk Brand ◽  
Stijn J. de Man ◽  
David Ong
Keyword(s):  
Clinical Performance ◽  
Point Of Care ◽  
Rapid Identification ◽  
Antigen Test ◽  
Large Variability ◽  
Clinical Sensitivity ◽  
Nursing Home Patients ◽  
Upper Respiratory ◽  
Antigen Tests ◽  
Respiratory Specimens

Abstract Purpose: The RT-qPCR in respiratory specimens is the gold standard for diagnosing acute COVID-19 infections. However, this test takes considerable time before test results become available, thereby delaying diagnosed COVID-19 patients to be treated and isolated immediately. Rapid antigen tests could overcome this problem and therefore a large number of COVID-19 rapid antigen tests have been developed. Methods: In this study clinical performances of five rapid antigen tests were compared to RT-qPCR in upper respiratory specimens from 80 patients. In addition, the rapid antigen test with the best test characteristics (Romed) was evaluated in a large prospective collection of randomly selected upper respiratory specimens from 900 different COVID-19 suspected patients (300 emergency room patients, 300 nursing home patients and 300 health care workers) in the period from October 24 to November 15, 2020. Results: Overall specificity was almost 100% and sensitivity ranged from 55.0% to 80.0%. The clinical specificity of the Romed test was 99.8% (95% CI 98.9-100). Overall clinical sensitivity in the study population was 73.3% (95% CI 67.9-78.2), whereas sensitivity in the different groups varied from 65.3% to 86.7%. Sensitivity was highest in patients with short-term symptoms. In a population with a COVID-19 prevalence of 1% the negative predictive value in all patients was 99.7%. Conclusion: There is a large variability in diagnostic performance between rapid antigen tests. The Romed rapid antigen test showed a good clinical performance in patients with high viral loads, which makes this antigen test suitable for rapid identification of COVID-19 infected patients.

scholarly journals Clinical evaluation of rapid point-of-care antigen tests for diagnosis of SARS-CoV-2 infection

2021 ◽  
Author(s):  
Johannes G. M. Koeleman ◽  
Henk Brand ◽  
Stijn J. de Man ◽  
David S. Y. Ong
Keyword(s):  
Health Care ◽  
Health Care Workers ◽  
Antigen Test ◽  
Duration Of Symptoms ◽  
Large Variability ◽  
Clinical Sensitivity ◽  
Care Workers ◽  
Upper Respiratory ◽  
Antigen Tests ◽  
Respiratory Specimens

AbstractThe RT-qPCR in respiratory specimens is the gold standard for diagnosing acute COVID-19 infections. However, this test takes considerable time before test results become available, thereby delaying patients from being diagnosed, treated, and isolated immediately. Rapid antigen tests could overcome this problem. In the first study, clinical performances of five rapid antigen tests were compared to RT-qPCR in upper respiratory specimens from 40 patients with positive and 40 with negative RTq-PCR results. In the second study, the rapid antigen test with one of the best test characteristics (Romed) was evaluated in a large prospective collection of upper respiratory specimens from 900 different COVID-19-suspected patients (300 emergency room patients, 300 nursing home patients, and 300 health care workers). Test specificities ranged from 87.5 to 100.0%, and test sensitivities from 55.0 to 80.0%. The clinical specificity of the Romed test was 99.8% (95% CI 98.9–100). Overall clinical sensitivity in the study population was 73.3% (95% CI 67.9–78.2), whereas sensitivity in the different patient groups varied from 65.3 to 86.7%. Sensitivity was 83.0 to 86.7% in patients with short duration of symptoms. In a population with a COVID-19 prevalence of 1%, the negative predictive value in all patients was 99.7%. There is a large variability in diagnostic performance between rapid antigen tests. The Romed rapid antigen test showed a good clinical performance in patients with high viral loads (RT-qPCR cycle threshold ≤30), which makes this antigen test suitable for rapid identification of COVID-19-infected health care workers and patients.

Correlation of COVID-19 antigen test and CBNAAT results at a single tertiary care hospital in North India: an experience

2021 ◽  
Vol 8 (5) ◽  
pp. 2427
Author(s):  
Surbhi Gupta ◽  
Anju Shukla ◽  
Poonam Singh ◽  
Areena H. Siddiqui
Keyword(s):  
Tertiary Care Hospital ◽  
Point Of Care ◽  
Tertiary Care ◽  
Uttar Pradesh ◽  
Nucleic Acid Amplification ◽  
North India ◽  
Care Hospital ◽  
Antigen Test ◽  
Discordant Group ◽  
Antigen Tests

Background: Nucleic acid amplification test (NAAT) is considered gold standard in the molecular diagnosis of CoV-2 infection but since it is costly, labor intensive and needs technical expertise, rapid chromatographic immunoassay for the qualitative detection of specific antigens to SARS CoV-2 have been devised. Objectives of this study was to compare the results of Antigen test and NAAT for CoV-2 infection carried out during the months of July and August 2020 by single tertiary care hospital in Lucknow, Uttar Pradesh and to determine the utility of rapid antigen test in the SARS CoV-2 diagnosis.Methods: All the patients who came to our hospital seeking admission during July 2020 and August 2020 were included in the study. A total of 1000 patients were included in this study.Results: Out of a total 1000 cases which were included in the study, 769 cases (76.9%) were found to be SARS CoV-2 negative by both antigen and CBNAAT, 100 cases (10.0%) were SARS CoV-2 positive by both antigen and CBNAAT tests. But in 131 cases (13.1%), antigen was not able to pick up the disease. It was also found that the Cycle Threshold (Ct) value for the discordant group was higher (Mean E= 28, Mean N2=33) when compared to the group where antigen was positive.Conclusions: The present study establishes the role of rapid antigen tests in contributing to the quick, point of care diagnosis of SARS CoV-2. These assays are safe, simple, and fast and can be used in local clinics and hospitals. These tests are very important for real-time patient management and infection control decision.

scholarly journals Proposal of De Novo Antigen Test for COVID-19: Ultrasensitive Detection of Spike Proteins of SARS-CoV-2

Diagnostics ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 594 ◽  
Author(s):  
Yuta Kyosei ◽  
Mayuri Namba ◽  
Sou Yamura ◽  
Rikiya Takeuchi ◽  
Noriko Aoki ◽  
...  
Keyword(s):  
De Novo ◽  
Limit Of Detection ◽  
False Negative ◽  
Cost Effective ◽  
Detection Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antigen Test ◽  
Virus Rna ◽  
Antigen Tests ◽  
Spike Proteins

Polymerase chain reaction (PCR)-based antigen tests are technically difficult, time-consuming, and expensive, and may produce false negative results requiring follow-up confirmation with computed tomography. The global coronavirus disease 2019 (COVID-19) pandemic has increased the demand for accurate, easy-to-use, rapid, and cost-effective antigen tests for clinical application. We propose a de novo antigen test for diagnosing COVID-19 using the combination of sandwich enzyme-linked immunosorbent assay and thio-nicotinamide adenine dinucleotide (thio-NAD) cycling. Our test takes advantage of the spike proteins specific to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The limit of detection of our test was 2.3 × 10−18 moles/assay. If the virus has ~25 spike proteins on its surface, our method should detect on the order of 10−20 moles of virus/assay, corresponding to ~104 copies of the virus RNA/assay. The detection sensitivity approaches that of PCR-based assays because the average virus RNA load used for PCR-based assays is ~105 copies per oro- or naso-pharyngeal swab specimen. To our knowledge, this is the first ultrasensitive antigen test for SARS-CoV-2 spike proteins that can be performed with an easy-to-use microplate reader. Sufficient sensitivity can be achieved within 10 min of thio-NAD cycling. Our antigen test allows for rapid, cost-effective, specific, ultrasensitive, and simultaneous multiple measurements of SARS-CoV-2, and has broad application for the diagnosis for COVID-19.

Effects of environmental conditions on point-of-care cardiac biomarker test performance during a simulated rescue: Implications for emergency and disaster response

2013 ◽  
Vol 8 (3) ◽  
pp. 205-212 ◽  
Author(s):  
Richard F. Louie, PhD, FACB ◽  
William J. Ferguson, BS ◽  
Corbin M. Curtis, BS ◽  
John H. Vy, BS ◽  
Chloe S. Tang, BS ◽  
...  
Keyword(s):  
Test Performance ◽  
Troponin I ◽  
Point Of Care ◽  
False Negative ◽  
Environmental Stresses ◽  
Marshall Islands ◽  
Rank Test ◽  
Cardiac Biomarker ◽  
Mortality And Morbidity ◽  
The Impact

Objective: To characterize the effects of environmental stress on point-of-care (POC) cardiac biomarker testing during a simulated rescue.Design: Multiplex test cassettes for cardiac troponin I (cTnI), brain natriuretic peptide (BNP), CKMB, myoglobin, and D-dimer were exposed to environmental stresses simulating a 24-hour rescue from Hawaii to the Marshall Islands and back. We used Tenney environmental chambers (T2RC and BTRC) to simulate flight conditions (20°C, 10 percent relative humidity) and ground conditions (22.3-33.9°C, 73-77 percent). We obtained paired measurements using stressed versus control (room temperature) cassettes at seven time points (T1-7 with T1,2,6,7 during flight and T3-5 on ground). We analyzed paired differences (stressed minus control) with Wilcoxon signed rank test. We assessed the impact on decision-making at clinical thresholds.Results: cTnI results from stressed test cassettes (n = 10) at T4 (p 0.05), T5 (p 0.01), and T7 (p 0.05) differed significantly from control, when testing samples with median cTnI concentration of 90 ng/L. During the ground rescue, 36.7 percent (11/30) of cTnI measurements from stressed cassettes generated significantly lowered results. At T5, 20 percent (2/10) of cTnI results were highly discrepant—stressed cassettes reported normal results, when control results were 100 ng/L. With sample median concentration of 108 pg/mL, BNP results from stressed test cassettes differed significantly from controls (p 0.05).Conclusion: Despite modest, short-term temperature elevation, environmental stresses led to erroneous results. False negative cTnI and BNP results potentially could miss acute myocardial infarction and congestive heart failure, confounded treatment, and increased mortality and morbidity. Therefore, rescuers should protect POC reagents from temperature extremes.

Comparison of Serological Tests for the Detection of Natural Heartworm Infection in Cats

2004 ◽  
Vol 40 (5) ◽  
pp. 376-384 ◽  
Author(s):  
Paul Berdoulay ◽  
Julie K. Levy ◽  
Patti S. Snyder ◽  
Michael J. Pegelow ◽  
Jennifer L. Hooks ◽  
...  
Keyword(s):  
Point Of Care ◽  
False Negative ◽  
Serological Tests ◽  
Male Worm ◽  
Single Male ◽  
Commercial Laboratory ◽  
Heartworm Infection ◽  
Antigen Tests ◽  
Antibody Tests ◽  
Positive Results

Serological tests were performed on 380 cats with necropsy-confirmed heartworm status to compare the performance of currently available commercial laboratory and point-of-care heart-worm serological tests in a heartworm-endemic area. Overall, antigen tests detected 79.3% to 86.2% of heartworm infections and were highly specific. Most cats with false-negative antigen tests had a single male worm. Antibody tests detected 62.1% to 72.4% of heartworm infections and had a wider range of false-positive results (1.4% to 19.1%) than antigen tests (0.3% to 2.0%). Serological tests for feline heartworm infection varied in diagnostic performance. Combining results from antigen and antibody tests achieved greater sensitivity than using either test alone.

scholarly journals What is the true place of the SARS‐CoV‐2 rapid point‐of‐care antigen test in the hospital setting? Lessons learned from real life.

2021 ◽  
Author(s):  
Steven Roger ◽  
Caroline Lefeuvre ◽  
Adeline Pivert ◽  
Alexandra Ducancelle ◽  
Dominique Savary ◽  
...  
Keyword(s):  
Point Of Care ◽  
Real Life ◽  
Hospital Setting ◽  
Lessons Learned ◽  
Antigen Test

scholarly journals Accuracy of Roche SARS-CoV-2 Rapid Antigen Test in Nasopharyngeal Swab: Clinical Impression Matters

2021 ◽  
Vol 2 (10) ◽  
pp. 929-938
Author(s):  
Khin Phyu Pyar ◽  
Khine Khine Su ◽  
Kyaw Wunna ◽  
Myo Thant ◽  
Kaung Myat ◽  
...  
Keyword(s):  
Predictive Value ◽  
False Negative ◽  
Hospital Setting ◽  
Clinical Samples ◽  
Nasopharyngeal Swab ◽  
Clinical Impression ◽  
Antigen Test ◽  
Rt Pcr ◽  
Ct Value

Background: In COVID-19 pandemic, the diagnosis and treatment must be as early as possible to save the life of each patient. Moreover, screening of asymptomatic carriers, close contacts or healthy subjects must not be delay to prevent transmission to publics. For confirmation of diagnosis of SARS-CoV-2 infection, nasopharyngeal swab must be tested either by real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR) tests or Rapid Antigen Test (RAT). RAT is faster, easier and cheaper; thus, it is suitable for health service in developing country. Objectives: The aim of this study was to assess the diagnostic accuracy of Roche SARS-CoV-2 Rapid Antigen Test (RAT) in diagnosing SARS-CoV-2 infection. Methods: Hospital based exploratory study was done in out-patient department and fever clinic, and molecular laboratory of No. (1) Defence Services General Hospital. Nasopharyngeal swabs were taken, and the Roche SARS- CoV-2 RAT was conducted in parallel with RT-PCR test (reference standard). Results: Among the 932 patients/subjects recruited, RT-PCR was positive in 468 individuals, corresponding to a prevalence of 50.2%. The RAT was positive in 363 patients (60.4%), false positive in 120 patients; it was negative in 569 individuals (39.6%), false negative in 225 patients. The overall sensitivity of the RAT was 51.9% (95% Confidence Interval [CI] 47.29-56.53) and, the specificity was 74.1% (95% CI 69.9-78.07); positive predictive value was 66.9% and negative predictive value was 60.5%. The sensitivity varied with Ct value; 78% in clinical samples with Ct values < 20, 57.5% in those with Ct values between 21 and 25, 41.8% in samples with Ct values between 26 and 30, and, 36.4% in samples with Ct value > 30. Conclusion: The accuracy of the SARS-CoV-2 Roche RAT in diagnosing SARS-CoV-2 infections was inferior to RT-PCR and manufacturer’s data. The sensitivity was with low Cycle threshold values < 20 which were inversely related to the viral load. RAT test should be used in association with clinical impression of physicians. In hospital setting especially in emergency department, the role of RAT should be reconsidered in those patients presenting with anosmia and some cases of dyspnoea, late symptoms in the course of disease, as the RAT results would be false negative. Other errors may arise if the operator for RAT has to handle more than recommended tests per hour especially in the peak of epidemics.

scholarly journals Characteristics of children and antigen test performance at a SARS-CoV-2 community testing site

2021 ◽  
Author(s):  
Laura Ford ◽  
Melissa J. Whaley ◽  
Melisa M. Shah ◽  
Phillip P. Salvatore ◽  
Hannah E. Segaloff ◽  
...  
Keyword(s):  
Test Performance ◽  
Point Of Care ◽  
Lower Sensitivity ◽  
Antigen Test ◽  
Rt Pcr ◽  
Culture Methods ◽  
Viral Culture ◽  
Asymptomatic Children ◽  
Testing Site ◽  
Antigen Tests

Background: Performance characteristics of SARS-CoV-2 antigen tests among children are limited despite the need for point-of-care testing in school and childcare settings. We describe children seeking SARS-CoV-2 testing at a community site and compare antigen test performance to real-time reverse transcription-polymerase chain reaction (RT-PCR) and viral culture. Methods: Two anterior nasal specimens were self-collected for BinaxNOW antigen and RT-PCR testing, along with demographics, symptoms, and exposure information from individuals ≥5 years at a community testing site. Viral culture was attempted on residual antigen or RT-PCR positive specimens. Demographic and clinical characteristics, and the performance of SARS-CoV-2 antigen tests, were compared among children (<18 years) and adults. Results: About one in ten included specimens were from children (225/2110); 16.4% (37/225) were RT-PCR positive. Cycle threshold values were similar among RT-PCR positive specimens from children and adults (22.5 vs 21.3, p=0.46) and among specimens from symptomatic and asymptomatic children (22.5 vs 23.2, p=0.39). Sensitivity of antigen test compared to RT-PCR was 73.0% (27/37) among specimens from children and 80.8% (240/297) among specimens from adults; among specimens from children, specificity was 100% (188/188), positive and negative predictive value were 100% (27/27) and 94.9% (188/198) respectively. Virus was isolated from 51.4% (19/37) of RT-PCR positive pediatric specimens; all 19 had positive antigen test results. Conclusions : With lower sensitivity relative to RT-PCR, antigen tests may not diagnose all positive COVID-19 cases; however, antigen testing identified children with live SARS-CoV-2 virus.

scholarly journals In vivo kinetics of SARS-CoV-2 infection and its relationship with a person’s infectiousness

2021 ◽  
Vol 118 (49) ◽  
pp. e2111477118
Author(s):  
Ruian Ke ◽  
Carolin Zitzmann ◽  
David D. Ho ◽  
Ruy M. Ribeiro ◽  
Alan S. Perelson
Keyword(s):  
Dynamic Models ◽  
False Negative ◽  
Reproductive Number ◽  
Upper Respiratory Tract ◽  
Rt Pcr ◽  
Viral Kinetics ◽  
Antigen Tests ◽  
The Impact ◽  
Kinetics Of

The within-host viral kinetics of SARS-CoV-2 infection and how they relate to a person’s infectiousness are not well understood. This limits our ability to quantify the impact of interventions on viral transmission. Here, we develop viral dynamic models of SARS-CoV-2 infection and fit them to data to estimate key within-host parameters such as the infected cell half-life and the within-host reproductive number. We then develop a model linking viral load (VL) to infectiousness and show a person’s infectiousness increases sublinearly with VL and that the logarithm of the VL in the upper respiratory tract is a better surrogate of infectiousness than the VL itself. Using data on VL and the predicted infectiousness, we further incorporated data on antigen and RT-PCR tests and compared their usefulness in detecting infection and preventing transmission. We found that RT-PCR tests perform better than antigen tests assuming equal testing frequency; however, more frequent antigen testing may perform equally well with RT-PCR tests at a lower cost but with many more false-negative tests. Overall, our models provide a quantitative framework for inferring the impact of therapeutics and vaccines that lower VL on the infectiousness of individuals and for evaluating rapid testing strategies.

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