scholarly journals Screening for SARS-CoV-2 infection in asymptomatic individuals using the Panbio™ COVID-19 Antigen Rapid Test (Abbott) compared to RT-qPCR

2020 ◽  
Author(s):  
Beatrice M.F. Winkel ◽  
Emma Schram ◽  
Hendrik Gremmels ◽  
Sylvia B. Debast ◽  
Rob Schuurman ◽  
...  
Keyword(s):  
Test Performance ◽  
Point Of Care ◽  
Rapid Test ◽  
High Specificity ◽  
Population Based ◽  
Sensitivity Analyses ◽  
Staff Members ◽  
Subsequent Test ◽  
Asymptomatic Individuals ◽  
Asymptomatic Subjects

AbstractBackgroundAntigen-based point of care tests for identification of SARS-CoV-2 may markedly enhance effectiveness of population-based controlling strategies. Previous studies have demonstrated acceptable sensitivity and high specificity compared to RT-qPCR in symptomatic individuals, but test performance for asymptomatic individuals is unknown.MethodsTest performance of the Panbio™ COVID-19 Ag Rapid Test (Abbott) was compared to RT-qPCR in a longitudinal cohort study of asymptomatic football players and staff members of professional football clubs. Based on timing of symptoms and prior and subsequent test results, positive RT-qPCR tests were categorized as pre-symptomatic, early or late infection or persistent RNA shedding.Findings2425 tests were performed in 824 individuals, of which 52 (6.3%) were SARS-CoV-2 positive based on RT-qPCR. There were 2406 paired sets from asymptomatic subjects for analysis. Sixteen Panbio™ tests were inconclusive, for which sensitivity analyses were performed (considering results as either positive or negative or being excluded). Sensitivity of Panbio™ ranged from 61.76% (95% CI 49.2-73.3) to 69.12% (95% CI: 56.7-79.8) and specificity from 99.53% (95% CI: 99.2-99.8) to 100% (95% CI: 99.8-100). Sensitivity of Panbio™ to detect subjects with pre-symptomatic/early infection (n= 42) ranged from 81.82% (95% CI: 67.3-91.8) to 90.91% (95% CI: 78.3-97.5) with specificity always above 99%.InterpretationIn asymptomatic subjects the Panbio™ COVID-19 Ag Rapid Test had sensitivity of 81.82% to 90.91% and specificity above 99% for identifying pre-symptomatic and early SARS-CoV-2 infection.FundingThis study was funded by the executing institutes. The Panbio™ COVID-19 Ag Rapid Tests were provided by the Ministry of Health, Welfare and Sport (VWS).

scholarly journals Screening for SARS-CoV-2 infection in asymptomatic individuals using the Panbio COVID-19 antigen rapid test (Abbott) compared with RT-PCR: a prospective cohort study

BMJ Open ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. e048206
Author(s):  
Beatrice Winkel ◽  
Emma Schram ◽  
Hendrik Gremmels ◽  
Sylvia Debast ◽  
Rob Schuurman ◽  
...  
Keyword(s):  
Cohort Study ◽  
Test Performance ◽  
Point Of Care ◽  
Rapid Test ◽  
High Specificity ◽  
Population Based ◽  
Sensitivity Analyses ◽  
Rt Pcr ◽  
Subsequent Test ◽  
Asymptomatic Individuals

BackgroundAntigen-based point-of-care tests for identification of SARS-CoV-2 may markedly enhance effectiveness of population-based controlling strategies. Previous studies have demonstrated >70% sensitivity and high specificity compared with reverse transcriptase real-time PCR (RT-PCR) in symptomatic individuals, but test performance for asymptomatic individuals is unknown.MethodsTest performance of the Panbio COVID-19 Ag Rapid Test (Abbott) was compared with RT-PCR in a longitudinal cohort study of asymptomatic football players and staff members of professional football clubs. Based on timing of symptoms and prior and subsequent test results, positive RT-PCR tests were categorised as presymptomatic, early or late infection, or persistent RNA shedding.Findings2425 tests were performed in 824 individuals, of which 52 (6.3%) were SARS-CoV-2 positive based on RT-PCR. There were 2406 paired sets from asymptomatic subjects for analysis. Sixteen Panbio tests were inconclusive, for which sensitivity analyses were performed (considering results as either positive or negative or being excluded). Sensitivity of Panbio for screening of asymptomatic individuals ranged from 80.0% (61.4–92.3) to 86.67% (69.2–96.2) and specificity from 99.53% (95% CI 99.2 to 99.8) to 100% (95% CI 99.8 to 100). Sensitivity of Panbio to detect subjects with presymptomatic/early infection (n=42) ranged from 81.82% (95% CI 67.3 to 91.8) to 90.91% (95% CI 78.3 to 97.5) with specificity always above 99%.InterpretationThe Panbio COVID-19 Ag rapid test identifies 81%–90% of presymptomatic and early asymptomatic SARS-CoV-2 infections with high specificity. This test may therefore be adopted in testing strategies such as targeted screening of specific populations where prevalence is low.

scholarly journals SARS-CoV-2 antibody seroprevalence in Lebanon: findings from the first nationwide serosurvey

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Abbas Hoballah ◽  
Rana El Haidari ◽  
Ghina Siblany ◽  
Fadi Abdel Sater ◽  
Samir Mansour ◽  
...  
Keyword(s):  
Test Performance ◽  
Point Of Care ◽  
Vaccination Campaign ◽  
Herd Immunity ◽  
Age Groups ◽  
Rapid Test ◽  
Population Based ◽  
P Value ◽  
Cumulative Number ◽  
Population Weight

Abstract Background Lebanon, a small country in the Middle East, remains severely affected by the COVID-19 pandemic. Seroprevalence surveys of anti-SARS-CoV-2 antibodies provide accurate estimates of SARS-CoV-2 infection and hence evaluate the extent of the pandemic. The present study aimed to evaluate the prevalence of SARS-CoV-2 antibodies in Lebanon and to compare the estimated cumulative number of COVID-19 cases with the officially registered number of laboratory-confirmed cases up to January 15, 2021. Methods A nationwide population-based serosurvey study was conducted in Lebanon between December 7, 2020, and January 15, 2021, before the initiation of the national vaccination program. The nCOVID-19 IgG & IgM point-of-care (POCT) rapid test was used to detect the presence of anti-SARS-COV-2 immunoglobulin G (IgG) in the blood. Seroprevalence was estimated after weighting for sex, age, and area of residence and adjusting for the test performance. Results Of the 2058 participants, 329 were positive for IgG SARS-COV-2, resulting in a crude seroprevalence of 16.0% (95% CI 14.4–17.6). The weighed seroprevalence was 15.9% (95% CI of 14.4 and 17.4). After adjusting for test performance, the population weight-adjusted seroprevalence was 18.5% (95% CI 16.8–20.2). This estimate implies that 895,770 individuals of the general population were previously infected by COVID-19 up to January 15, 2021 in Lebanon. The overall estimated number of subjects with previous SARS-CoV-2 infection was three times higher than the officially reported cumulative number of confirmed cases. Seroprevalence was similar across age groups and sexes (p-value > 0.05). However, significant differences were revealed across governorates. Conclusions Our results suggest that the Lebanese population is still susceptible to SARS-CoV-2 infection and far from achieving herd immunity. These findings represent an important contribution to the surveillance of the COVID-19 pandemic in Lebanon and to the understanding of how this virus spreads. Continued surveillance for COVID-19 cases and maintaining effective preventive measures are recommended to control the epidemic spread in conjunction with a national vaccination campaign to achieve the desired level of herd immunity against COVID-19.

scholarly journals Point-of-care serological assays for SARS-CoV-2 in a UK hospital population: potential for enhanced case finding

2020 ◽  
Author(s):  
Scott Pallett ◽  
Aatish Patel ◽  
Gary Davies ◽  
Luke Moore
Keyword(s):  
Test Performance ◽  
Serological Test ◽  
Point Of Care ◽  
Rapid Test ◽  
Antibody Test ◽  
Preliminary Evaluation ◽  
Hospital Inpatient ◽  
Case Identification ◽  
Global Pandemic ◽  
Population Potential

Abstract Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic, causing over 3,600,000 reported cases and 250,000 deaths worldwide.1 Case identification has predominantly been made by real-time polymerase chain reaction (PCR) during the acute phase and largely restricted to healthcare laboratories. Serological assays are emerging but independent validation is urgently required to assess their utility. Where a plurality of point-of-care (POC) SARS-CoV-2 antibody test kits have become available, we will therefore aim to evaluate a range of kits against the current available gold-standard diagnostic test of PCR in an initial, exploratory study. We will then proceed to carry out testing with 200 hospital inpatients using the OrientGene COVID-19 IgG/IgM Rapid Test Cassette against PCR in order to undergo a preliminary evaluation of POC serological test performance characteristics within a hospital inpatient cohort.

scholarly journals A rapid and affordable point of care test for antibodies against SARS-CoV-2 based on hemagglutination and artificial intelligence interpretation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vanessa Redecke ◽  
Kazuki Tawaratsumida ◽  
Erin T. Larragoite ◽  
Elizabeth S. C. P. Williams ◽  
Vicente Planelles ◽  
...  
Keyword(s):  
Test Performance ◽  
Learning Algorithm ◽  
Point Of Care ◽  
Method Comparison ◽  
High Specificity ◽  
Turnaround Time ◽  
Analysis Tool ◽  
Point Of Care Test ◽  
Specificity And Sensitivity ◽  
A Cell

AbstractDiagnostic tests that detect antibodies (AB) against SARS-CoV-2 for evaluation of seroprevalence and guidance of health care measures are important tools for managing the COVID-19 pandemic. Current tests have certain limitations with regard to turnaround time, costs and availability, particularly in point-of-care (POC) settings. We established a hemagglutination-based AB test that is based on bi-specific proteins which contain a dromedary-derived antibody (nanobody) binding red blood cells (RBD) and a SARS-CoV-2-derived antigen, such as the receptor-binding domain of the Spike protein (Spike-RBD). While the nanobody mediates swift binding to RBC, the antigen moiety directs instantaneous, visually apparent hemagglutination in the presence of SARS-CoV-2-specific AB generated in COVID-19 patients or vaccinated individuals. Method comparison studies with assays cleared by emergency use authorization demonstrate high specificity and sensitivity. To further increase objectivity of test interpretation, we developed an image analysis tool based on digital image acquisition (via a cell phone) and a machine learning algorithm based on defined sample-training and -validation datasets. Preliminary data, including a small clinical study, provides proof of principle for test performance in a POC setting. Together, the data support the interpretation that this AB test format, which we refer to as ‘NanoSpot.ai’, is suitable for POC testing, can be manufactured at very low costs and, based on its generic mode of action, can likely be adapted to a variety of other pathogens.

scholarly journals Application of a point-of-care test for the serodiagnosis of typhoid fever in Nigeria and the need for improved diagnostics

2011 ◽  
Vol 5 (07) ◽  
pp. 520-526 ◽  
Author(s):  
Stella Ifeanyi Smith ◽  
Moses Bamidele ◽  
Muinah Fowora ◽  
Helen T. Goodluck ◽  
Emmanuel A. Omonigbehin ◽  
...  
Keyword(s):  
Typhoid Fever ◽  
Point Of Care ◽  
Normal Population ◽  
Rapid Test ◽  
High Specificity ◽  
Latex Agglutination ◽  
Clinical Suspicion ◽  
Confirmatory Test ◽  
Molecular Testing ◽  
Blood Samples

Introduction: There is an urgent need for affordable point-of-care diagnostics for the differentiation of febrile illnesses and the confirmation of typhoid in endemic countries. Methodology: Blood samples were collected from febrile patients with clinical suspicion of typhoid and screened for typhoid fever using the Widal and Typhi Dri Dot tests, while stool and blood samples were screened for Salmonella Typhi using the culture method as well as PCR as a confirmatory test. Results: A high proportion of febrile patients from Lagos with clinical suspicion of typhoid fever reacted positively in a simple and rapid latex agglutination assay for typhoid fever, indicating that this illness is a common and presumably under-diagnosed health problem in this metropolis. Seropositivity was 19.2% in the rapid test compared with 22.9% in the classical Widal test. The confirmation of typhoid in these seropositive patients appeared cumbersome because of negative blood cultures and low DNA yield in molecular testing. A review of the literature revealed that in Nigeria seroprevalence rates can be high in the normal population and that pathogens other than S. Typhi are often isolated from the blood of seropositive febrile patients. Conclusion: The simplicity and the relatively high specificity (97.8%) of the rapid test as determined in a study performed in Indonesia calls for a further validation of this promising test for use in Africa.

scholarly journals Seroprevalence of COVID-19 virus infection in Guilan province, Iran

2020 ◽  
Author(s):  
Maryam Shakiba ◽  
Seyed Saeed Hashemi Nazari ◽  
Fardin Mehrabian ◽  
Seyed Mahmoud Rezvani ◽  
Zahra Ghasempour ◽  
...  
Keyword(s):  
Virus Infection ◽  
Test Performance ◽  
Care Center ◽  
Rapid Test ◽  
Population Based ◽  
Asymptomatic Infection ◽  
Phone Call ◽  
Infected People ◽  
Health Care Center ◽  
Population Weight

AbstractBackgroundThe extent of infection by coronavirus disease 2019 has not been well known. In this study we aimed to determine seropositivity of COVID-19 virus infection in population of a highly affected area in north of Iran.MethodsIn a population-based cluster random sampling design through phone call invitation, a total of 196 household including 551 subjects agreed to participate in this study. Each participant were taken 50ml blood sample at health care center. Rapid test kits were used to detect antibody against COVID-19. Crude, population-weight adjusted and test performance adjusted prevalence of antibody seropositivity to SARS-CoV-2 were reported.ResultsThe prevalence of antibody seropositivity was 22% (95%CI: 19-26%). The population weight adjusted estimate was 21% (95%CI: 14-29%) and test performance adjusted prevalence was 33% (95%CI: 28-39%). Based on these estimates the range of infected people in this province would be between 518000 and 777000.ConclusionThe population seropositivity prevalence of COVID-19 virus infection indicated that the asymptomatic infection is much higher than the number of confirmed cases of COVID-19. This estimate can be used to better detect infection fatality rate and decide for public policy guidelines.

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 Evaluation of the Access Bio CareStartTM rapid SARS-CoV-2 antigen test in asymptomatic individuals tested at a community mass-testing program in Western Massachusetts

2021 ◽  
Author(s):  
Sara Suliman ◽  
Wilfredo R. Matias ◽  
Isabel R Fulcher ◽  
Francisco J. Molano ◽  
Shannon Collins ◽  
...  
Keyword(s):  
Point Of Care ◽  
Quantitative Polymerase Chain Reaction ◽  
High Specificity ◽  
Antigen Test ◽  
Predictive Values ◽  
Prevalence Estimates ◽  
Moderate Sensitivity ◽  
Testing Site ◽  
Asymptomatic Individuals ◽  
Sensitivity Specificity

Background: Point-of-care antigen-detecting rapid diagnostic tests (RDTs) for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) represent a scalable tool for SARS-CoV-2 infections surveillance. Data on their performance in real-world community settings is paramount for their implementation. Method: We evaluated the accuracy of CareStartTM COVID-19 Antigen test (CareStart) in a testing site in Holyoke, Massachusetts. We compared CareStart to a SARS-CoV-2 reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) reference, using anterior nasal swab samples. We calculated the sensitivity, specificity, and expected positive and negative predictive values at different SARS-CoV-2 prevalence estimates. Results: We performed 666 tests on 591 unique individuals. 573 (86%) were asymptomatic. There were 52 positive tests by RT-qPCR. The sensitivity of CareStart was 49.0% (95% Confidence Interval (CI): 34.8 - 63.4) and specificity was 99.5% (95% CI: 98.5 - 99.9). Among positive RT-qPCR tests, the median cycle threshold (Ct) was significantly lower in samples that tested positive on CareStart. Using a Ct ≤ 30 as a benchmark for positivity increased the sensitivity to 64.9% (95% CI: 47.5 - 79.8). Conclusions: CareStart has a high specificity and moderate sensitivity. The utility of RDTs, such as CareStart, in mass implementation should prioritize use cases in which a higher specificity is more important.

scholarly journals 674. Evaluation of the Access Bio CareStart™ Rapid SARS-CoV-2 Antigen Test in Asymptomatic Individuals Tested at a Community Mass-testing Program in Western Massachusetts

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S439-S439
Author(s):  
Wilfredo Matias ◽  
Sara suliman ◽  
Isabel Fulcher ◽  
Francisco Molano ◽  
Shannon Collins ◽  
...  
Keyword(s):  
Point Of Care ◽  
Quantitative Polymerase Chain Reaction ◽  
Rapid Test ◽  
High Specificity ◽  
Population Data ◽  
Performance Characteristics ◽  
Test Results ◽  
Antigen Test ◽  
Predictive Values ◽  
Cycle Threshold

Abstract Background Point-of-care antigen-detecting rapid diagnostic tests (RDTs) to detect Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) represent a scalable tool for surveillance of active SARS-CoV-2 infections in the population. Data on the performance of these tests in real-world community settings will be paramount for their implementation to combat the COVID-19 pandemic. Methods We evaluated the performance characteristics of the CareStartTM COVID-19 Antigen Test (CareStart) in a community testing site in Holyoke, Massachusetts. We compared CareStart to a SARS-CoV-2 reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) reference, both using anterior nasal swab samples. We calculated the sensitivity, specificity, and the expected positive and negative predictive values at different SARS-CoV-2 prevalence estimates. Results We performed 666 total tests on 591 unique individuals. 573 (86%) were asymptomatic. There were 52 positive tests by RT-qPCR. The sensitivity of CareStart was 49.0% (95% Confidence Interval (CI): 34.8 – 63.4) and specificity was 99.5% (95% CI: 98.5 – 99.9). Among positive RT-qPCR tests, the median cycle threshold (Ct) was significantly lower in samples that tested positive on CareStart. Using a Ct less than or equal to 30 as a benchmark for positivity increased the sensitivity of the test to 64.9% (95% CI: 47.5 – 79.8). Performance characteristics of CareStart test results benchmarked against the RT-qPCR gold standard (excluding undetermined results). Examples of images of CareStart rapid test showing variable band intensities. N2 gene RT-qPCR Cycle threshold (Ct) values corresponding to positive and negative CareStart rapid antigen test results for all RT-qPCR positive samples (n=52). Conclusion Our study shows that CareStart has a high specificity and moderate sensitivity. The utility of RDTs, such as CareStart, in mass implementation should prioritize use cases in which a higher specificity is more important, such as triage tests to rule-in active infections in community surveillance programs. Disclosures All Authors: No reported disclosures

scholarly journals Seroprevalence of anti-SARS-CoV-2 antibodies in Iquitos, Loreto, Peru

2021 ◽  
Author(s):  
Carlos Álvarez-Antonio ◽  
Graciela Meza-Sánchez ◽  
Carlos Calampa ◽  
Wilma Casanova ◽  
Cristiam Carey ◽  
...  
Keyword(s):  
Test Performance ◽  
Herd Immunity ◽  
Age Groups ◽  
Rapid Test ◽  
Prevalence Ratio ◽  
Population Based ◽  
Current Data ◽  
Survey Analysis ◽  
Population Based Study

SummaryBackgroundDetection of SARS-CoV-2 antibodies among people at risk is critical for understanding both the prior transmission of COVID-19 and vulnerability of the population to the continuing transmission and, when done serially, the intensity of ongoing transmission over an interval in a community. In this study, we estimated the seroprevalence of COVID-19 in a representative population-based cohort of Iquitos, one of the regions with the highest mortality rates from COVID-19 in Peru, where a devastating number of cases occurred in March 2020.MethodsWe conducted a population-based study of transmission tested each participant using the COVID-19 IgG/IgM Rapid Test from Orient Gene Biotech and used survey analysis methods to estimate seroprevalence accounting for the sampling design effect and test performance characteristics. Here we report results from the baseline (13 to 18 July 2020) and the first month of follow-up (13 to 18 August 2020) study.FindingsWe enrolled a total of 716 participants and estimated seroprevalence of 70.0% (95% CI: 67.0%–73.4%), a test-re-test positivity of 65% (95% CI: 61.0%–68.3%), and an incidence of new exposures of 1.8% (95% CI: 0.9%–3.2%) data that suggest that transmission is ongoing but is occurring at low levels. We observed significant differences in the seroprevalence between age groups, with participants 18 to 29 years of age having lower seroprevalence than children <12 years of age (Prevalence ratio =0.85 [PR]; 95% CI: 0.73 – 0.98), suggesting that children were not refractory to infection in this setting.InterpretationIquitos demonstrates one of the highest rates of seroprevalence of COVID-19 worldwide. Current data shows a limited case burden in Iquitos for the past seven months and suggests that these levels are sufficient to provide significant but incomplete herd immunity.FundingDirección Regional de Salud de Loreto, DIRESA, Loreto, Peru

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