scholarly journals Analytic sensitivity of the Abbott BinaxNOW lateral flow immunochromatographic assay for the SARS-CoV-2 Omicron variant

2022 ◽  
Author(s):  
Sanjat Kanjilal ◽  
Sujata Chalise ◽  
Adnan Shami Shah ◽  
Chi-An Cheng ◽  
Yasmeen Senussi ◽  
...  
Keyword(s):  
Lateral Flow ◽  
Tissue Tropism ◽  
Threshold Values ◽  
Clinical Sensitivity ◽  
Viral Loads ◽  
Test Characteristics ◽  
Testing Strategies ◽  
The Us ◽  
Antigen Tests ◽  
Two Populations

The emergence of the SARS-CoV-2 Omicron variant has motivated a re-evaluation of the test characteristics for lateral flow immunochromatographic assays (LFIAs), commonly referred to as rapid antigen tests. To address this need, we evaluated the analytic sensitivity of one of the most widely used LFIAs in the US market, the Abbott BinaxNOW COVID-19 Ag At-Home Card using 32 samples of Omicron and 30 samples of the Delta variant. Samples were chosen to intentionally over-represent the range of viral loads where differences are most likely to appear. We found no changes in the analytic sensitivity of the BinaxNOW assay by variant even after controlling for variation in cycle threshold values in the two populations. Similar to prior studies, the sensitivity of the assay is highly dependent on the amount of virus present in the sample. While the analytic sensitivity of the BinaxNOW LFIA remains intact versus the Omicron variant, its clinical sensitivity is influenced by the interaction between viral replication, the dynamics of tissue tropism and the timing of sampling. Further research is necessary to optimally adapt current testing strategies to robustly detect early infection by the Omicron variant to prevent transmission.

A prospective nationwide observational study of agreement of antigen tests on oral pharyngeal swabs or less invasive testing with RT-qPCR, for detecting SARS-CoV-2 in adults: Protocol description (Preprint)

2021 ◽  
Author(s):  
Uffe Vest Schneider ◽  
Jenny Dahl Knudsen ◽  
Anders Koch ◽  
Nikolai Søren Kirkby ◽  
Jan Gorm Lisby
Keyword(s):  
Confidence Intervals ◽  
Predictive Value ◽  
Large Scale ◽  
Reference Method ◽  
Lateral Flow ◽  
Clinical Samples ◽  
Sampling Location ◽  
Analytical Sensitivity ◽  
Clinical Sensitivity ◽  
Antigen Tests

BACKGROUND The SARS-CoV-2 pandemic has resulted in an unprecedented level of world-wide testing for epidemiologic and diagnostic purposes, and due to the extreme need for tests, the gold standard reverse transcription polymerase chain reaction (RT-qPCR) testing capacity has been unable to meet the overall global testing demand. Consequently, although current literature has shown the sensitivity of rapid antigen tests (RATs) to be inferior to RT-qPCR, RATs have been implemented on a large scale without solid data on performance. OBJECTIVE This study will compare analytical and clinical sensitivities and specificities of 50 lateral flow or laboratory based RATs and three Strand Invasion Based Amplification (SIBA)-rt-PCR tests from 30 manufacturers to RT-qPCR on samples obtained from the deep oropharynx. In addition, the study will compare sensitivities and specificities of the included RATs as well as RT-qPCR on clinical samples obtained from the deep oropharynx, anterior nasal cavity, saliva, deep nasopharynx and expired air to RT-qPCR from deep oropharyngeal samples. METHODS In the prospective part of the study, 200 individuals found SARS-CoV-2 positive and 200 individuals found SARS-CoV-2 negative by routine RT-qPCR testing will be re-tested with each RAT applying RT-qPCR as the reference method. In the retrospective part of the study, 304 deep oropharyngeal cavity swabs divided into four groups based on RT-qPCR Cq levels will be tested by each RAT. RESULTS The results will be reported in several manuscripts with different aims. The first manuscript will report retrospective (analytical sensitivity, overall and stratified into different Cq range groups) and prospective (clinical sensitivity) data for RATs with RT-qPCR results as the reference method. The second manuscript will report results for RAT based on anatomical sampling location. The third manuscript will compare different anatomical sampling locations by RT-qPCR testing. The fourth manuscript will focus on RATs that rely on central laboratory testing. Test from four different manufactures will be compared for analytical performance data on retrospective deep oropharyngeal swab samples. The fifth manuscript will report the results of four RATs applied both as professional use and as self-test. The last manuscript will report the results from two breath tests participating in the study. Comparison of sensitivity and specificity between RATs will be done using McNemar for paired samples and chi-squared test for unpaired samples. Comparison of PPV and NPV between RATs will be done by bootstrap test. 95 % confidence intervals for sensitivity, specificity, positive predictive value and negative predictive value are calculated as bootstrap confidence intervals CONCLUSIONS The study will compare the sensitivities of a large number of RATs for SARS-CoV-2 compared to RT-qPCR and will address whether lateral flow based RATs test differ significantly from laboratory based RATS. The anatomical test location for both RAT and RT-qPCR will be compared. CLINICALTRIAL ClinicalTrials.gov NCT04913116

scholarly journals Establishment of an evaluation panel for the decentralized technical evaluation of the sensitivity of 31 rapid detection tests for SARS-CoV-2 diagnostics

2021 ◽  
Author(s):  
Andreas Puyskens ◽  
Eva Krause ◽  
Janine Michel ◽  
Micha Nuebling ◽  
Heinrich Scheiblauer ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
Rapid Diagnostic Tests ◽  
Rapid Diagnostics ◽  
Infected People ◽  
Clinical Sensitivity ◽  
Viral Loads ◽  
Evaluation Panel ◽  
Technical Evaluation ◽  
Antigen Tests ◽  
Validation Strategy

Background The detection of SARS-CoV-2 with rapid diagnostic tests has become an important tool to identify infected people and break infection chains. These rapid diagnostic tests are usually based on antigen detection in a lateral flow approach. Aims & Methods While for PCR diagnostics the validation of a PCR assay is well established, for antigen tests e.g. rapid diagnostic tests there is no common validation strategy. Here we present the establishment of a panel of 50 pooled clinical specimens that cover a SARS-CoV-2 concentration range from approximately 1.1 x 109 to 420 genome copies per mL of specimen. The panel was used to evaluate 31 rapid diagnostic tests in up to 6 laboratories. Results Our results show that there is significant variation in the detection limits and the clinical sensitivity of different rapid diagnostic tests. We conclude that the best rapid diagnostic tests can be applied to reliably identify infectious individuals who are presenting with SARS-CoV-2 loads correlated to 106 genome copies per mL of specimen. Infected individuals displaying SARS-CoV-2 genome loads corresponding to less than 106 genome copies per mL will be identified by only some rapid diagnostics tests, while many tests miss these viral loads to a large extent. Conclusions Sensitive RDTs can be applied to identify infectious individuals with high viral loads, but not to identify infected individuals.

scholarly journals Establishment of a specimen panel for the decentralised technical evaluation of the sensitivity of 31 rapid diagnostic tests for SARS-CoV-2 antigen, Germany, September 2020 to April 2021

2021 ◽  
Vol 26 (44) ◽  
Author(s):  
Andreas Puyskens ◽  
Eva Krause ◽  
Janine Michel ◽  
C Micha Nübling ◽  
Heinrich Scheiblauer ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
Rapid Diagnostic Tests ◽  
Pcr Assay ◽  
Infected People ◽  
Clinical Sensitivity ◽  
Viral Loads ◽  
Technical Evaluation ◽  
Antigen Tests ◽  
Pcr Diagnostics ◽  
Validation Strategy

Introduction The detection of SARS-CoV-2 with rapid diagnostic tests (RDT) has become an important tool to identify infected people and break infection chains. These RDT are usually based on antigen detection in a lateral flow approach. Aim We aimed to establish a comprehensive specimen panel for the decentralised technical evaluation of SARS-CoV-2 antigen rapid diagnostic tests. Methods While for PCR diagnostics the validation of a PCR assay is well established, there is no common validation strategy for antigen tests, including RDT. In this proof-of-principle study we present the establishment of a panel of 50 pooled clinical specimens that cover a SARS-CoV-2 concentration range from 1.1 × 109 to 420 genome copies per mL of specimen. The panel was used to evaluate 31 RDT in up to six laboratories. Results Our results show that there is considerable variation in the detection limits and the clinical sensitivity of different RDT. We show that the best RDT can be applied to reliably identify infectious individuals who present with SARS-CoV-2 loads down to 106 genome copies per mL of specimen. For the identification of infected individuals with SARS-CoV-2 loads corresponding to less than 106 genome copies per mL, only three RDT showed a clinical sensitivity of more than 60%. Conclusions Sensitive RDT can be applied to identify infectious individuals with high viral loads but not to identify all infected individuals.

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.

scholarly journals Lateral flow antigen tests can sensitively detect live cultured virus of the SARS-CoV-2 B.1.1.7 lineage

2021 ◽  
Author(s):  
Konstantina Kontogianni ◽  
Ana I. Cubas-Atienzar ◽  
Dominic Wooding ◽  
Kate Buist ◽  
Caitlin R. Thompson ◽  
...  
Keyword(s):  
Lateral Flow ◽  
Antigen Tests

scholarly journals Pathogenicity of novel goose-origin astrovirus causing gout in goslings

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Dan Yin ◽  
Jiajun Tian ◽  
Jing Yang ◽  
Yi Tang ◽  
Youxiang Diao
Keyword(s):  
Biochemical Parameters ◽  
Clinical Symptoms ◽  
Future Research ◽  
Tissue Tropism ◽  
Virus Shedding ◽  
Viral Loads ◽  
Blood Biochemical ◽  
Copy Numbers ◽  
Viral Copy ◽  
Kidney Liver

Abstract Background A novel goose-origin astrovirus (GoAstV) has broken out across China in recent years, causing gout in goslings with a mortality rate of around 50%. However, our understanding of the dynamic distribution, tissue tropism and pathogenesis of GoAstV is incomplete. In order to assess its pathogenicity, one-day-old goslings were inoculated separately with GoAstV via oral and subcutaneous injection routes. Results Clinical symptoms, gross and microscopic lesions, blood biochemical parameters and viral loads were detected and recorded for 20 days after infection. Typical gout was observed in experimental goslings. GoAstV can be replicated in tissues and cause pathological damage, especially in the kidney, liver, heart and spleen. Virus-specific genomic RNA was detected in blood, cloacal swabs and all representative tissues, and virus shedding was detected up to 20 days after inoculation, suggesting that GoAstV has a wide tissue tropism and spread systematically after inoculation. The viral copy numbers examined in kidney were the highest, followed by spleen and liver. Conclusion This experiment determined the accurate value of viral loads and biochemical indicators of GoAstV-induced goslings. These findings increase our understanding of the pathogenicity of GoAstV in goslings and provide more reference for future research.

scholarly journals Comparison of four commercial, automated antigen tests to detect SARS-CoV-2 variants of concern

2021 ◽  
Author(s):  
Andreas Osterman ◽  
Maximilian Iglhaut ◽  
Andreas Lehner ◽  
Patricia Späth ◽  
Marcel Stern ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Point Of Care ◽  
Study Cohort ◽  
Operating Characteristics ◽  
Testing Strategies ◽  
Level 3 ◽  
Amino Acid Mutations ◽  
Antigen Tests ◽  
Roche Diagnostics ◽  
Analytical Sensitivities

AbstractA versatile portfolio of diagnostic tests is essential for the containment of the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic. Besides nucleic acid-based test systems and point-of-care (POCT) antigen (Ag) tests, quantitative, laboratory-based nucleocapsid Ag tests for SARS-CoV-2 have recently been launched. Here, we evaluated four commercial Ag tests on automated platforms and one POCT to detect SARS-CoV-2. We evaluated PCR-positive (n = 107) and PCR-negative (n = 303) respiratory swabs from asymptomatic and symptomatic patients at the end of the second pandemic wave in Germany (February–March 2021) as well as clinical isolates EU1 (B.1.117), variant of concern (VOC) Alpha (B.1.1.7) or Beta (B.1.351), which had been expanded in a biosafety level 3 laboratory. The specificities of automated SARS-CoV-2 Ag tests ranged between 97.0 and 99.7% (Lumipulse G SARS-CoV-2 Ag (Fujirebio): 97.03%, Elecsys SARS-CoV-2 Ag (Roche Diagnostics): 97.69%; LIAISON® SARS-CoV-2 Ag (Diasorin) and SARS-CoV-2 Ag ELISA (Euroimmun): 99.67%). In this study cohort of hospitalized patients, the clinical sensitivities of tests were low, ranging from 17.76 to 52.34%, and analytical sensitivities ranged from 420,000 to 25,000,000 Geq/ml. In comparison, the detection limit of the Roche Rapid Ag Test (RAT) was 9,300,000 Geq/ml, detecting 23.58% of respiratory samples. Receiver-operating-characteristics (ROCs) and Youden’s index analyses were performed to further characterize the assays’ overall performance and determine optimal assay cutoffs for sensitivity and specificity. VOCs carrying up to four amino acid mutations in nucleocapsid were detected by all five assays with characteristics comparable to non-VOCs. In summary, automated, quantitative SARS-CoV-2 Ag tests show variable performance and are not necessarily superior to a standard POCT. The efficacy of any alternative testing strategies to complement nucleic acid-based assays must be carefully evaluated by independent laboratories prior to widespread implementation.

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