scholarly journals Nasopharyngeal Panbio COVID-19 antigen performed at point-of-care has a high sensitivity in symptomatic and asymptomatic patients with higher risk for transmission and older age

2021 ◽  
Author(s):  
Mar Masiá ◽  
Marta Fernández-González ◽  
Manuel Sánchez ◽  
Mar Carvajal ◽  
José Alberto García ◽  
...  
Keyword(s):  
Test Performance ◽  
Point Of Care ◽  
Rapid Test ◽  
High Sensitivity ◽  
Older Age ◽  
Antigen Test ◽  
Rt Pcr ◽  
Asymptomatic Patients ◽  
Clinical Scenarios ◽  
Nasal Swabs

Abstract Background Performance of point-of-care tests in different clinical scenarios and on different samples remains undetermined. We comprehensively evaluated the performance of the nasopharyngeal Panbio COVID-19 antigen Rapid-Test-Device. Method Prospective study including consecutive patients attending three primary care centers (PCC) and an emergency department. The antigen test was performed at point-of-care in nasopharyngeal and nasal swabs, and in saliva. Positive and negative percent agreement (PPA, NPA) were calculated with the RT-PCR assay as reference standard. Results Of 913 patients included, 296 (32.3%) were asymptomatic and 690 (75.6%) came from the PCC. Nasopharyngeal swabs were collected from 913, nasal swabs from 659, and saliva from 611 patients. RT-PCR was positive in 196 (21.5%) nasopharyngeal samples (NPS). Overall PPA (95% CI) in NPS was 60.5% (53.3-67.4), and it was lower in nasal swabs (44.7%) and saliva (23.1%). Test performance in NPS was largely dependent on the cycle threshold (Ct) in RT-PCR, with PPA of 94% for Ct≤25 and 80% for Ct<30. In symptomatic patients, the PPA was 95% for Ct≤25; 85% for Ct<30, and 89% for the symptom triad of fever, cough and malaise. Performance was also dependent on age, with PPA of 100% in symptomatic patients >50 years with Ct<25. In asymptomatic patients, the PPA was 86% for Ct<25. In all cases, NPA was 100%. Conclusion The nasopharyngeal Panbio COVID-19 antigen test performed at point-of-care has a good sensitivity in symptomatic patients with Ct<30 and older age. The test was useful to identify asymptomatic patients with lower Ct values.

scholarly journals Nasopharyngeal Panbio COVID-19 antigen performed at point-of-care has a high sensitivity in symptomatic and asymptomatic patients with higher risk for transmission and older age

2020 ◽  
Author(s):  
Mar Masiá ◽  
Marta Fernández-González ◽  
Manuel Sánchez ◽  
Mar Carvajal ◽  
José Alberto García ◽  
...  
Keyword(s):  
Point Of Care ◽  
Real Life ◽  
Older Age ◽  
Antigen Test ◽  
Rt Pcr ◽  
Life Conditions ◽  
Asymptomatic Patients ◽  
Clinical Scenarios ◽  
Highly Sensitive ◽  
Nasal Swabs

ABSTRACTBackgroundPerformance of point-of-care tests in clinical practice remains undetermined. We aimed to evaluate the performance of the nasopharyngeal Panbio COVID-19 antigen Rapid Test Device in real-life conditions in different clinical scenarios.MethodProspective study conducted in three primary care centers (PCC) and an emergency department. The antigen test was performed at point-of-care in nasopharyngeal and nasal swabs, and in saliva. Positive and negative percent agreement (PPA, NPA) were calculated with the RT-PCR assay as reference standard.ResultsOf 913 patients included, 296 (32.3%) were asymptomatic and 690 (75.6%) came from the PCC. Nasopharyngeal swabs were collected from 913, nasal swabs from 659, and saliva from 611 patients. RT-PCR was positive in 196 (21.5%) nasopharyngeal samples (NPS). Overall PPA (95% CI) in NPS was 60.5% (53.3-67.4), and it was lower in nasal swabs (44.7%) and saliva (23.1%). Test performance in NPS was largely dependent on the cycle threshold (Ct) in RT-PCR, with PPA>90% for Ct≤25 and ≥80% for Ct<30. In symptomatic patients, the PPA was 95% for Ct≤25; ≥85% for Ct<30, and 89% for the symptom triad of fever, cough and malaise. Performance was also dependent on age, with PPA of 100% in symptomatic patients >50 years with Ct<25. In asymptomatic patients, the PPA was 86% for Ct<25. In all cases, NPA was 100%.ConclusionThe nasopharyngeal Panbio COVID-19 antigen test performed at point-of-care is highly sensitive in symptomatic patients, particularly with Ct<30 and older age. The test was useful to identify asymptomatic patients with lower Ct values and therefore with contagious risk.Key pointsThe nasopharyngeal Panbio-COVID-19 antigen test performed in real-life conditions at point-of-care is highly sensitive in symptomatic patients, particularly with Ct<30 and older age. The test is useful to identify asymptomatic patients with lower Ct values and therefore with contagious risk.

scholarly journals ASSESSMENT OF PERFORMANCE AND IMPLEMENTATION CHARACTERISTICS OF RAPID POINT OF CARE SARS-CoV-2 ANTIGEN TESTING IN KENYA

2021 ◽  
Author(s):  
Jesse Gitaka ◽  
Eva Muthamia ◽  
Samuel Mbugua ◽  
Mary Mungai ◽  
Gama Bandawe ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Test Performance ◽  
Gold Standard ◽  
Point Of Care ◽  
Turnaround Time ◽  
Ease Of Use ◽  
Control Measures ◽  
Antigen Test ◽  
Rt Pcr ◽  
Predictive Values

Abstract Background: The COVID-19 pandemic has resulted in a need for rapid identification of infectious cases. Testing barriers have prohibited adequate screening for SARS COV2, resulting in significant delays in treatment provision and commencement of outbreak control measures. This study aimed to generate evidence on the performance and implementation characteristics of the BD Veritor rapid antigen test as compared to the gold standard test for diagnosis of SARS COV2 in Kenya. Methods: This was a field test performance evaluation in symptomatic and asymptomatic adults undergoing testing for SARS COV2. Recruited participants were classified as SARS-CoV2-positive based on the locally implemented gold standard reverse transcription polymerase chain reaction (RT-PCR) test performed on nasopharyngeal swabs. 272 antigen tests were performed with simultaneous gold standard testing, allowing us to estimate sensitivity, specificity, positive and negative predictive values for the BD Veritor rapid antigen test platform. Implementation characteristics were assessed using the Consolidated Framework for Implementation Research for feasibility, acceptability, turn-around time, and ease-of-use metrics. Results and Discussion: We enrolled 97 PCR negative symptomatic and 128 PCR negative asymptomatic, and 28 PCR positive symptomatic and 19 PCR positive asymptomatic participants. Compared to the gold standard, the sensitivity of the BD Veritor antigen test was 94% (95% confidence interval [CI] 86.6 to 100.0) while the specificity was 98% (95% confidence interval [CI] 96 to 100). The sensitivity of BD Veritor antigen test was higher among symptomatic (100%) compared to asymptomatic (84%) participants, although this difference was not statistically significant. There was also a lack of association between cycle threshold value and sensitivity of BD Veritor test. The BD Veritor test had quick turnaround time and minimal resource requirements, and laboratory personnel conducting testing felt that it was easier to use than the gold standard RT-PCR. Conclusion: The BD Veritor rapid antigen test exhibited excellent sensitivity and specificity when used to detect SARS-CoV-2 infection among both symptomatic and asymptomatic individuals in varied population settings in Kenya. It was feasible to implement and easy to use, with rapid turnaround time.

scholarly journals Potential Use of Antigen-Based Rapid Test for SARS-CoV-2 in Respiratory Specimens in Low-Resource Settings in Egypt for Symptomatic Patients and High-Risk Contacts

2020 ◽  
Author(s):  
Abeer Mohamed Abdelrazik ◽  
Shahira Morsy Elshafie ◽  
Hossam M Abdelaziz
Keyword(s):  
Test Performance ◽  
Healthcare Professionals ◽  
Rapid Test ◽  
University Hospital ◽  
Antigen Test ◽  
Rt Pcr ◽  
Viral Loads ◽  
Viral Transport Medium ◽  
Public Health Challenges ◽  
Polymerase Chain

Abstract Objective Because of the rapidly emerging SARS-CoV-2 pandemic and its wide public health challenges, rapid diagnosis is essential to decrease the spread. Antigen-based rapid detection tests are available; however, insufficient data about their performance are available. Methods The lateral-flow immunochromatographic BIOCREDIT COVID-19 antigen test was evaluated using nasopharyngeal swabs in a viral transport medium from patients with confirmed infection, contacts, and exposed healthcare professionals at Fayoum University Hospital in Egypt. Test performance was determined in comparison to the SARS-CoV-2 real-time reverse-transcription polymerase chain reaction (RT-PCR) test. Results Three hundred ten specimens from 3 categories—patients with confirmed diagnoses of COVID-19, contacts, and exposed healthcare professionals—were included; 188 specimens were RT-PCR-positive, from which 81 were detected by rapid antigen test. Overall sensitivity was 43.1%. Sensitivity was significantly higher in specimens with high viral loads. Conclusion Poor sensitivity of the BIOCREDIT COVID-19 test does not permit its use for diagnosis, and it can only be used in conjunction with RT-PCR for screening.

scholarly journals Analytical performances of the COVISTIX and Panbio antigen rapid tests for SARS-CoV-2 detection in an unselected population (all commers)

2021 ◽  
Author(s):  
Francisco Garcia-Cardenas ◽  
Alba Franco ◽  
Ricardo Cortes ◽  
Jenny Bertin ◽  
Rafael Valdez ◽  
...  
Keyword(s):  
High Performance ◽  
Close Contact ◽  
Point Of Care ◽  
Steady Increase ◽  
Antigen Test ◽  
Rt Pcr ◽  
Viral Shedding ◽  
Specificity And Sensitivity ◽  
Asymptomatic Patients ◽  
Unselected Population

Importance: A steady increase in acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases worldwide is causing some regions of the world to withstand a third or even fourth wave of contagion. Swift detection of SARS-CoV-2 infection is paramount for the containment of cases, prevention of sustained contagion; and most importantly, for the reduction of mortality. Objective: To evaluate the performance and validity of the COVISTIXTM rapid antigen test, for the detection of SARS-CoV-2 in an unselected population and compare it to PanbioTM rapid antigen test and RT-PCR. Design: This is comparative effectiveness study; samples were collected at two point-of-care facilities in Mexico City between May and August 2021. Participants: Recruited individuals were probable COVID-19 cases, either symptomatic or asymptomatic persons that were at risk of infection due to close contact to SARS-CoV-2 positive cases. Diagnostic intervention: RT-PCR was used as gold standard for detection of SARS-CoV-2 in nasal and nasopharyngeal swabs, study subjects were tested in parallel either with the COVISTIXTM or with PanbioTM rapid antigen test. Main outcome: Diagnostic performance of the COVISTIXTM assay is adequate in all commers since its accuracy parameters were not affected in samples collected after 7 days of symptom onset, and it detected almost 65% of samples with a Ct-value between 30 and 34. Results: For the population tested with COVISTIXTM (n=783), specificity and sensitivity of the was 96.0% (CI95% 94.0-98.0) and 81% (CI95% 76.0-85.0), as for the PanbioTM (n=2202) population, was 99.0% (CI95%: 0.99-1.00) and 62% (CI%: 58.0-64.0%), respectively. Conclusions and relevance: The COVISTIXTM rapid antigen test shows a high performance in all comers, thus, this test is also adequate for testing patients who have passed the peak of viral shedding or for asymptomatic patients.

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 A rapid, high-sensitivity SARS-CoV-2 nucleocapsid immunoassay to aid diagnosis of acute COVID-19 at the point of care

2020 ◽  
Author(s):  
Paul K. Drain ◽  
Madhavi Ampajwala ◽  
Christopher Chappel ◽  
Andre B. Gvozden ◽  
Melanie Hoppers ◽  
...  
Keyword(s):  
Real Time ◽  
Symptom Onset ◽  
Real Time Pcr ◽  
Nucleocapsid Protein ◽  
Point Of Care ◽  
High Sensitivity ◽  
Antigen Test ◽  
Rt Pcr ◽  
Duration Of Symptoms ◽  
Microfluidic Immunoassay

AbstractBackgroundThe LumiraDx SARS-CoV-2 antigen test, which uses a high-sensitivity, microfluidic immunoassay to detect the nucleocapsid protein of SARS-CoV-2, was evaluated for diagnosing acute COVID-19 in adults and children across point-of-care settings.MethodsTwo paired anterior nasal swabs or two paired nasopharyngeal swabs were collected from each participant. Swabs were tested by the LumiraDx SARS-CoV-2 antigen test and compared with real-time PCR (rt-PCR; Roche cobas 6800 platform). Positive- and negative predictive values and likelihood ratios were calculated. Results stratified based on gender, age, duration of symptoms, and rt-PCR cycle threshold.ResultsOut of the 512 participants, aged 0-90 years, of this prospective validation study, 414 (81%) were symptomatic for COVID-19 and 123 (24%) swabs were positive for SARS-CoV-2 based on rt-PCR testing. Compared with rt-PCR, the 12-minute swab test had 97.6% sensitivity and 96.6% specificity within 12 days of symptom onset, representing the period of infectivity. All (100%) samples detected within 33 rt-PCR cycles were also identified using the antigen test. Results were consistent across age and gender. Despite being performed by minimally trained healthcare workers, the user error rate of the test system was 1%.ConclusionThe rapid high-sensitivity assay using nasopharyngeal or anterior nasal sampling may offer significant improvements for diagnosing acute SARS-CoV-2 infection in clinic- and community-based settings.SummaryA 12-minute nasal swab test detects 97.6% of COVID-19 infections, compared to gold standard real-time PCR testing, up to 12 days following symptom onset using a microfluidic immunoassay for SARS-CoV-2 nucleocapsid protein.

scholarly journals Diagnostic Utility of Antigen Detection Rapid Diagnostic Tests for Covid- 19: A Systematic Review and Meta-Analysis

2021 ◽  
Author(s):  
Mina Ebrahimi ◽  
Narges Nazari Harmooshi ◽  
Fakher Rahim
Keyword(s):  
Diagnostic Tests ◽  
Point Of Care ◽  
Meta Analysis ◽  
False Negative ◽  
Rapid Test ◽  
Rapid Diagnostic Tests ◽  
Lower Sensitivity ◽  
Sample Type ◽  
Rt Pcr ◽  
Asymptomatic Patients

Background: Early detection of coronavirus disease (COVID-19) infection to improve disease management, becomes the greatest challenge. Despite high sensitivity of RT-PCR, not only it was reported that 20-67% of infected patients have false negative results. Rapid diagnostic tests (RDTs) are widely used as a point-of-care test for SARS-CoV-2 detection in both pharyngeal and blood specimens. To be less time-consuming, not seem so costly, and requiring no special training make it more favorable, but the low sensitivity is the main limitation. Several reports indicated rapid test of blood and pharyngeal samples has the same sensitivity as the RT-PCR, but some reports have lower sensitivity especial in asymptomatic patients. Methods: In the present survey, we investigate the eligible studies for sensitivity and specificity of rapid tests and explore the factors that influence the result to help better diagnose COVID-19 infection. 20 studies met the inclusion criteria, which impose 33 different tests. Results: Our findings showed, type of sample, type of assay, time of sampling, and load of virus influence on sensitivity of RDTs. Conclusion: This research extends our knowledge of how to improve the sensitivity of RDTs to better diagnose of infected patients to address the controlling COVID-19 pandemic.

scholarly journals Evaluation of the INDICAID COVID-19 Rapid Antigen Test in symptomatic populations and asymptomatic community testing

2021 ◽  
Author(s):  
Ricky Chiu ◽  
Noah Kojima ◽  
Garrett Mosley ◽  
Kwok Kin Cheng ◽  
David Pereira ◽  
...  
Keyword(s):  
Positive Result ◽  
Clinical Evaluation ◽  
Rapid Test ◽  
Symptomatic Patient ◽  
Detection Methods ◽  
Antigen Test ◽  
Rt Pcr ◽  
Percent Agreement ◽  
Asymptomatic Patients ◽  
Testing Algorithm

Background As the COVID-19 pandemic continues to cause substantial morbidity and mortality, there is an increased need for rapid, accessible assays for SARS-CoV-2 detection. Methods Here we present a clinical evaluation and real-world implementation of the INDICAID COVID-19 Rapid Antigen Test (INDICAID Rapid Test). A multi-site clinical evaluation of the INDICAID Rapid Test using prospectively collected samples from symptomatic subjects was performed. The INDICAID Rapid Test was then implemented at COVID-19 outbreak screening centers in Hong Kong to screen individuals for COVID-19 to prioritize confirmatory RT-PCR testing among asymptomatic populations. Results The clinical evaluation in symptomatic patient populations demonstrated a positive percent agreement and negative percent agreement of 85.3% (95% confidence interval [95% CI]: 75.6% - 91.6%) and 94.9% (95% CI: 91.6% - 96.9%), respectively, when compared to laboratory-based RT-PCR testing. When used during outbreak testing of 22,994 asymptomatic patients, the INDICAID Rapid Test demonstrated a positive percent agreement of 84.2% (95% CI: 69.6% - 92.6%) and a negative percent agreement of 99.9% (95% CI: 99.9% - 100%) compared to laboratory-based RT-PCR testing. When incorporated in a testing algorithm, the INDICAID Rapid Test reduced time to confirmatory positive result from an average 10.85 hours (standard RT-PCR only) to 0.84 hours, depending on the algorithm. Conclusion The INDICAID Rapid Test has excellent performance when compared to laboratory-based RT-PCR testing, and when used in tandem with RT-PCR, reduces the time to confirmatory positive result.

scholarly journals Performance and Operational Evaluation of the Access Bio CareStart Rapid Antigen Test in a High-throughput Drive-through Community Testing Site in Massachusetts

2021 ◽  
Author(s):  
Nira R. Pollock ◽  
Kristine Tran ◽  
Jesica R. Jacobs ◽  
Amber E. Cranston ◽  
Sita Smith ◽  
...  
Keyword(s):  
High Throughput ◽  
Point Of Care ◽  
High Sensitivity ◽  
Antigen Test ◽  
Rt Pcr ◽  
Asymptomatic Children ◽  
Adults And Children ◽  
Moderate Sensitivity ◽  
Testing Site ◽  
Sensitivity Specificity

AbstractBackgroundTo facilitate deployment of point-of-care testing for SARS-CoV-2, we evaluated the Access Bio CareStart COVID-19 Antigen test in a high-throughput, drive-through, free community testing site using anterior nasal (AN) swab RT-PCR for clinical testing.MethodsConsenting symptomatic and asymptomatic children (≤18 years) and adults received dual AN swabs. CareStart testing was performed with temperature/humidity monitoring. All tests had two independent reads to assess inter-operator agreement. Patients with positive CareStart results were called and instructed to isolate pending RT-PCR results. The paired RT-PCR result was the reference for sensitivity and specificity calculations.ResultsOf 1603 participants, 1245 adults and 253 children had paired RT-PCR/CareStart results and complete symptom data. 83% of adults and 87% of children were asymptomatic. CareStart sensitivity/specificity were 84.8% (95% confidence interval [CI] 71.1-93.7)/97.2% (92.0-99.4) and 85.7% (42.1-99.6)/89.5% (66.9-98.7) in adults and children, respectively, within 5 days of symptoms. Sensitivity/specificity were 50.0% (41.0-59.0)/99.1% (98.3-99.6) in asymptomatic adults and 51.4% (34.4-68.1)/97.8% (94.5-99.4) in asymptomatic children. Sensitivity in all 234 RT-PCR-positive people was 96.3% with cycle threshold (Ct) ≤25, 79.6% with Ct ≤30, and 61.4% with Ct ≤35. All 21 false positive CareStart tests had faint but normal bands. Inter-operator agreement was 99.5%. Operational challenges included identification of faint test bands and inconsistent swab elution volumes.ConclusionsCareStart had high sensitivity in people with Ct ≤25 and moderate sensitivity in symptomatic people overall. Specificity was unexpectedly lower in symptomatic versus asymptomatic people. Excellent inter-operator agreement was observed, but operational challenges indicate that operator training is warranted.

scholarly journals Diagnostic Utility of Antigen Detection Rapid Diagnostic Tests for Covid- 19: a Systematic Review and Meta-analysis

2021 ◽  
Author(s):  
Somayeh Ghasemi ◽  
Narges Nazari Harmooshi ◽  
Fakher Rahim
Keyword(s):  
Diagnostic Tests ◽  
Point Of Care ◽  
Meta Analysis ◽  
False Negative ◽  
Rapid Test ◽  
Rapid Diagnostic Tests ◽  
Lower Sensitivity ◽  
Sample Type ◽  
Rt Pcr ◽  
Asymptomatic Patients

Abstract Background: Early detection of coronavirus disease (COVID-19) infection to improve disease management, becomes the greatest challenge. Despite high sensitivity of RT-PCR, not only it was reported that 20-67% of infected patients have false negative results. Rapid diagnostic tests (RDTs) are widely used as a point-of-care test for SARS-CoV-2 detection in both pharyngeal and blood specimens. To be less time-consuming, not seem so costly, and requiring no special training make it more favorable, but the low sensitivity is the main limitation. Several reports indicated rapid test of blood and pharyngeal samples has the same sensitivity as the RT-PCR, but some reports have lower sensitivity especial in asymptomatic patients. Methods: In the present survey, we investigate the eligible studies for sensitivity and specificity of rapid tests and explore the factors that influence the result to help better diagnose COVID-19 infection. 20 studies met the inclusion criteria, which impose 33 different tests. Results: Our findings showed, type of sample, type of assay, time of sampling, and load of virus influence on sensitivity of RDTs. Conclusion: This research extends our knowledge of how to improve the sensitivity of RDTs to better diagnose of infected patients to address the controlling COVID-19 pandemic.

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