scholarly journals Assessment of twenty-two SARS-CoV-2 rapid antigen tests against SARS-CoV-2: A laboratory evaluation study

2021 ◽  
Author(s):  
Joshua M Deerain ◽  
Thomas Tran ◽  
Mitchell B Batty ◽  
Yano Yoga ◽  
Julian Druce ◽  
...  
Keyword(s):  
Cell Culture ◽  
Population Level ◽  
Evaluation Study ◽  
Transmission Risk ◽  
Laboratory Evaluation ◽  
Analytical Sensitivity ◽  
Test Results ◽  
Antigen Test ◽  
Clinical Sensitivity ◽  
Antigen Tests

Background Rapid antigen testing is widely used as a way of scaling up population-level testing. To better inform antigen test deployment in Australia, we evaluated 22 commercially available antigen tests, including an assessment of culture infectivity. Methods Analytical sensitivity was evaluated against SARS-CoV-2 B.1.617.2 (Delta), reported as TCID50/mL, cycle threshold (Ct) value and viral load (RNA copies/mL). Specificity was assessed against non-SARS-CoV-2 viruses. Clinical sensitivity and correlation with cell culture infectivity was assessed using the Abbott PanBio™ COVID-19 Ag test. Results Nineteen kits consistently detected SARS-CoV-2 antigen equivalent to 1.3x10^6 copies/mL (5.8x10^3 TCID50/mL). Specificity for all kits was 100%. Compared to RT-PCR the Abbott PanBio™ COVID-19 Ag test was 52.6% (95% CI, 41.6% to 63.3%) sensitive, with a 50% detection probability for infectious cell culture at 5.9 log10 RNA copies/mL (95% CI, 5.3 to 6.5 log10 copies/mL). Antigen test sensitivity was 97.6% (95% CI, 86.3% to 100.0%) compared to positive infectious in cell culture. Conclusions Antigen test positivity correlated with positive viral culture, suggesting antigen test results may determine SARS-CoV-2 transmission risk. Sensitivity varied considerably between test kits and highlights the need for ongoing systematic post-market evaluation, providing valuable information to help guide antigen test selection and deployment.

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.

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 Diagnostic performance of a novel digital immunoassay (RapidTesta SARS-CoV-2): a prospective observational study with 1,127 nasopharyngeal samples

2021 ◽  
Author(s):  
Hiromichi Suzuki ◽  
Yusaku Akashi ◽  
Atsuo Ueda ◽  
Yoshihiko Kiyasu ◽  
Yuto Takeuchi ◽  
...  
Keyword(s):  
Diagnostic Performance ◽  
Prospective Observational Study ◽  
Test Results ◽  
Antigen Test ◽  
Rt Pcr ◽  
Asymptomatic Patients ◽  
Pcr Method ◽  
Antigen Tests ◽  
Positive Line ◽  
Test Cassette

Introduction: Digital immunoassays are generally regarded as superior tests for the detection of infectious disease pathogens, but there have been insufficient data concerning SARS-CoV-2 immunoassays. Methods: We prospectively evaluated a novel digital immunoassay (RapidTesta SARS-CoV-2). Two nasopharyngeal samples were simultaneously collected for antigen tests and RT-PCR. Real-time RT-PCR for SARS-CoV-2, using a method developed by the National Institute of Infectious Diseases, Japan, served as the reference RT-PCR method. Results: During the study period, 1,127 nasopharyngeal samples (symptomatic patients: 802, asymptomatic patients: 325) were evaluated. For digital immunoassay antigen tests, the sensitivity was 78.3% (95% CI: 67.3%-87.1%) and the specificity was 97.6% (95% CI: 96.5%-98.5%). When technicians visually analyzed the antigen test results, the sensitivity was 71.6% (95% CI: 59.9%-81.5%) and the specificity was 99.2% (95% CI: 98.5%-99.7%). Among symptomatic patients, the sensitivity was 89.4% (95% CI; 76.9%-96.5%) with digital immunoassay antigen tests, and 85.1% (95% CI; 71.7%-93.8%) with visually analyzed the antigen test, respectively. Conclusions: The findings indicated that RapidTesta SARS-CoV-2 analysis with the DIA device had sufficient analytical performance for the detection of SARS-CoV-2 in nasopharyngeal samples. When positive DIA results are recorded without a visually recognizable red line at the positive line location on the test cassette, additional RT-PCR evaluation should be performed.

scholarly journals Comparison of Antigen Tests and qPCR in Rapid Diagnostics of Infections Caused by SARS-CoV-2 Virus

Viruses ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 17
Author(s):  
Adrianna Klajmon ◽  
Aldona Olechowska-Jarząb ◽  
Dominika Salamon ◽  
Agnieszka Sroka-Oleksiak ◽  
Monika Brzychczy-Włoch ◽  
...  
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Molecular Techniques ◽  
Nucleic Acid Amplification ◽  
Laboratory Diagnostics ◽  
Test Results ◽  
Rapid Diagnostics ◽  
Antigen Test ◽  
Qualified Personnel ◽  
Replication Phase ◽  
Antigen Tests

Diagnostics of the coronavirus disease 2019 (COVID-19) using molecular techniques from the collected respiratory swab specimens requires well-equipped laboratory and qualified personnel, also it needs several hours of waiting for results and is expensive. Antigen tests appear to be faster and cheaper but their sensitivity and specificity are debatable. The aim of this study was to compare a selected antigen test with quantitative polymerase chain reaction (qPCR) tests results. Nasopharyngeal swabs were collected from 192 patients with COVID-19 symptoms. All samples were tested using Vitassay qPCR SARS-CoV-2 kit and the Humasis COVID-19 Ag Test (MedSun) antigen immunochromatographic test simultaneously. Ultimately, 189 samples were tested; 3 samples were excluded due to errors in taking swabs. The qPCR and antigen test results were as follows: 47 positive and 142 negative, and 45 positive and 144 negative, respectively. Calculated sensitivity of 91.5% and specificity of 98.6% for the antigen test shows differences which are not statistically significant in comparison to qPCR. Our study showed that effectiveness of the antigen tests in rapid laboratory diagnostics is high enough to be an alternative and support for nucleic acid amplification tests (NAAT) in the virus replication phase in the course of COVID-19.

scholarly journals Clinical Validation of Automated and Rapid mariPOC SARS-CoV-2 Antigen Test

2021 ◽  
Author(s):  
Juha M. Koskinen ◽  
Petri Antikainen ◽  
Kristina Hotakainen ◽  
Anu Haveri ◽  
Niina Ikonen ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Limit Of Detection ◽  
Clinical Performance ◽  
High Capacity ◽  
Nasopharyngeal Swab ◽  
Analytical Sensitivity ◽  
Clinical Sensitivity ◽  
Qrt Pcr ◽  
Antigen Tests ◽  
Novel Coronavirus

ABSTRACTNovel SARS coronavirus causing COVID-19 was recognized in late 2019. Diagnostics was quickly ramped up worldwide based on the detection of viral RNA. Based on the scientific knowledge for pre-existing coronaviruses, it was expected that the RNA of this novel coronavirus will be detected at significant rates from symptomatic and asymptomatic individuals due to existence of non-infectious RNA. To increase the efficacy of diagnostics, surveillance, screening and pandemic control, rapid methods, such as antigen tests, are needed for decentralized testing and to assess infectiousness. The objectives were to verify analytical sensitivity and specificity, and assess the clinical sensitivity, specificity and usability of a novel automated mariPOC SARS-CoV-2 test based on sophisticated optical laser technology detecting viral structure proteins. Analytical performance was verified using bacterial and viral preparations. Clinical performance of the test was evaluated against qRT-PCR in a retrospective study with nasopharyngeal swab specimens (N=211) collected from symptomatic patients suspected of acute SARS-CoV-2 infections. Sensitivity and specificity of the mariPOC test were 92.3% (12/13) and 100.0% (198/198), respectively. The test’s limit of detection was 22 PFU/test and it had no cross-reactions with the tested respiratory microbes. Our study shows that the mariPOC can detect infectious individuals already in 20 minutes while clinical sensitivity close to qRT-PCR is achieved in two hours or less. The test targets conserved epitopes of SARS-CoV-2 nucleoprotein, making it robust against strain variations. The new test is a promising and versatile tool for syndromic testing of symptomatic cases and for high capacity infection control screening.

scholarly journals Comparison of seven commercial SARS-CoV-2 rapid point-of-care antigen tests: a single-centre laboratory evaluation study

2021 ◽  
Author(s):  
Victor M Corman ◽  
Verena Claudia Haage ◽  
Tobias Bleicker ◽  
Marie Luisa Schmidt ◽  
Barbara Mühlemann ◽  
...  
Keyword(s):  
Point Of Care ◽  
Evaluation Study ◽  
Laboratory Evaluation ◽  
Single Centre ◽  
Antigen Tests

scholarly journals Routine asymptomatic testing strategies for airline travel during the COVID-19 pandemic: a simulation analysis

2020 ◽  
Author(s):  
Mathew V Kiang ◽  
Elizabeth T Chin ◽  
Benjamin Q Huynh ◽  
Lloyd A C Chapman ◽  
Isabel Rodríguez-Barraquer ◽  
...  
Keyword(s):  
Population Level ◽  
Transmission Risk ◽  
Secondary Outcome ◽  
Individual Risk ◽  
Primary Study ◽  
Antigen Test ◽  
Risk Of Infection ◽  
Testing Strategies ◽  
Airline Travel ◽  
Pcr Test

AbstractBackgroundAirline travel has been significantly reduced during the COVID-19 pandemic due to concern for individual risk of SARS-CoV-2 infection and population-level transmission risk from importation. Routine viral testing strategies for COVID-19 may facilitate safe airline travel through reduction of individual and/or population-level risk, although the effectiveness and optimal design of these “test-and-travel” strategies remain unclear.MethodsWe developed a microsimulation of SARS-CoV-2 transmission in a cohort of airline travelers to evaluate the effectiveness of various testing strategies to reduce individual risk of infection and population-level risk of transmission. We evaluated five testing strategies in asymptomatic passengers: i) anterior nasal polymerase chain reaction (PCR) within 3 days of departure; ii) PCR within 3 days of departure and PCR 5 days after arrival; iii) rapid antigen test on the day of travel (assuming 90% of the sensitivity of PCR during active infection); iv) rapid antigen test on the day of travel and PCR 5 days after arrival; and v) PCR within 3 days of arrival alone. The travel period was defined as three days prior to the day of travel and two weeks following the day of travel, and we assumed passengers followed guidance on mask wearing during this period. The primary study outcome was cumulative number of infectious days in the cohort over the travel period (population-level transmission risk); the secondary outcome was the proportion of infectious persons detected on the day of travel (individual-level risk of infection). Sensitivity analyses were conducted.FindingsAssuming a community SARS-CoV-2 incidence of 50 daily infections, we estimated that in a cohort of 100,000 airline travelers followed over the travel period, there would be a total of 2,796 (95% UI: 2,031, 4,336) infectious days with 229 (95% UI: 170, 336) actively infectious passengers on the day of travel. The pre-travel PCR test (within 3 days prior to departure) reduced the number of infectious days by 35% (95% UI: 27, 42) and identified 88% (95% UI: 76, 94) of the actively infectious travelers on the day of flight; the addition of PCR 5 days after arrival reduced the number of infectious days by 79% (95% UI: 71, 84). The rapid antigen test on the day of travel reduced the number of infectious days by 32% (95% UI: 25, 39) and identified 87% (95% UI: 81, 92) of the actively infectious travelers; the addition of PCR 5 days after arrival reduced the number of infectious days by 70% (95% UI: 65, 75). The post-travel PCR test alone (within 3 days of landing) reduced the number of infectious days by 42% (95% UI: 31, 51). The ratio of true positives to false positives varied with the incidence of infection. The overall study conclusions were robust in sensitivity analysis.InterpretationRoutine asymptomatic testing for COVID-19 prior to travel can be an effective strategy to reduce individual risk of COVID-19 infection during travel, although post-travel testing with abbreviated quarantine is likely needed to reduce population-level transmission due to importation of infection when traveling from a high to low incidence setting.

scholarly journals Application of a Serial Antigen Based Testing Strategy for SARS-CoV-2 and Student Adherence in a University Setting, Wisconsin — October–November 2020

2021 ◽  
Author(s):  
John Paul Bigouette ◽  
Laura Ford ◽  
Ian Pray ◽  
Kimberly Langolf ◽  
Juliana Kahrs ◽  
...  
Keyword(s):  
Male Students ◽  
Test Results ◽  
Antigen Test ◽  
Testing Strategy ◽  
Rt Pcr ◽  
Testing Strategies ◽  
Serial Testing ◽  
Polymerase Chain ◽  
Antigen Tests ◽  
University Setting

Abstract Background Serial SARS-CoV-2 testing has been implemented at institutions of higher education (IHEs) and other settings. Testing strategies can include algorithms specifying confirmatory reverse transcription polymerase chain reaction (RT-PCR) testing after an antigen test. It is unknown how testing strategies perform detecting SARS-CoV-2, including individual adherence to serial testing requirements. Methods Student serial testing adherence was defined as completing ≥80% of weekly tests from October 5–November 14, 2020 and evaluated using logistic regression. Medical records were reviewed for all positive antigen test encounters and 10% of daily negative antigen test encounters during October 19–November 30, 2020. Results were used to estimate the proportion of individuals requiring only antigen tests, requiring and completing RT-PCR testing, and associated costs of tests. Results Two-thirds (66.5%; 1,166/1,754) of eligible on-campus students adhered to weekly testing; female students were more adherent (adjusted odds ratio [aOR]:2.07, 95% CI:1.66–2.59) than male students. Of all antigen test encounters, 11.5% (1,409/12,305) reported >1 COVID-19 symptoms. Of non-COVID-19 exposed antigen test encounters, 88% (10,386/11,769) did not require confirmatory RT-PCR testing. Only 28% (390/1,387) of testing encounters had an associated recommended confirmatory RT-PCR test performed. We estimated the testing strategy captured 61% (235/389) of predicted RT-PCR positive specimens. Conclusions At this IHE, most students voluntarily adhered to serial testing. The majority of antigen test results did not require confirmatory RT-PCR testing, but when required, most students did not obtain it. Including strategies to increase the proportion of individuals obtaining indicated confirmatory testing might improve the testing program’s performance.

scholarly journals Performance of antigenic detection of SARS-CoV-2 in nasopharyngeal samples

2021 ◽  
Author(s):  
Catalina Lunca ◽  
Cristian Cojocaru ◽  
Irina Luciana Gurzu ◽  
Florin Dumitru Petrariu ◽  
Elena Cojocaru
Keyword(s):  
Virus Detection ◽  
Protein Detection ◽  
Protein S ◽  
Screening Tests ◽  
Test Results ◽  
Antigen Test ◽  
Qrt Pcr ◽  
Qualitative Detection ◽  
Antigen Tests ◽  
Pcr Test

Objectives: SARS-CoV-2 virus detection on nasopharyngeal specimens to infected individuals has become a challenge for the COVID-19 pandemic outbreak. We aim at comparing the performance of antigenic detection of SARS-CoV-2 in nasopharyngeal samples via an immunochromatographic method to molecular detection via qRT-PCR. Materials and Methods: 47 nasopharyngeal exudates were collected from suspicious COVID-19 cases. The samples were performed both via the qualitative immuno-chromatographic method for S protein detection in the SARS-CoV-2 structure, using fluorescent labelled anti-protein S antibodies and via qRT-PCR test for the qualitative detection of the screening gene E and the specific ORF1ab region of the RNA-SARS-CoV-2. Results: There was a fair correlation between the positive antigen tests and the positive PCR assays measured through threshold cycle ORF1ab region (Ct orf). A better correlation was obtained between the antigen test results and the Ct orf when including patients with Ct orf below 25. Conclusions: Using antigen tests as screening tests is useful on symptomatic persons during the viral replication period, therefore during the contagious period. A positive test shows a high predictive value for infection, while a negative antigen test result via immuno-chromatography must be confirmed by a qRT-PCR test.

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