scholarly journals On Pilot Massive COVID-19 Testing by Antigen Tests in Europe. Case Study: Slovakia

2021 ◽  
Vol 13 (1) ◽  
pp. 45-57
Author(s):  
Jaroslav Frnda ◽  
Marek Durica
Keyword(s):  
Mathematical Models ◽  
National Health ◽  
Health Authority ◽  
False Positive ◽  
Infection Rates ◽  
Rt Pcr ◽  
Sick People ◽  
Antigen Tests ◽  
Antigen Testing

This paper provides a summary of mass COVID-19 testing of almost the entire population in Slovakia by antigen tests. We focused on the results delivered by two testing rounds and analyzed the benefits and weaknesses of such type of testing. We prepared mathematical models to critically examine the effectiveness of the testing, and we also estimated the number of potentially sick people that would become infected by those marked as positives by antigen tests. Our calculations have proven that antigen testing in hotspots can flatten the curve of daily newly reported cases significantly, but in regions with low-risk of COVID-19, the benefit of such testing is questionable. As for the regions with low infection rates, we could only estimate the proportion of true and false-positive cases because the national health authority had not validated the results by RT–PCR tests. Therefore, this work can serve as an introductory study on the first nationwide testing by antigen tests in Europe.

scholarly journals Sensitivity of rapid antigen testing and RT-PCR performed on nasopharyngeal swabs versus saliva samples in COVID-19 hospitalized patients: results of a prospective comparative trial (RESTART)

2021 ◽  
Author(s):  
Antonios Kritikos ◽  
Giorgia Caruana ◽  
René Brouillet ◽  
John-Paul Miroz ◽  
Abed-Maillard Samia ◽  
...  
Keyword(s):  
Comparative Trial ◽  
Hospitalized Patients ◽  
Rt Pcr ◽  
Duration Of Symptoms ◽  
Non Invasive ◽  
Viral Transport Medium ◽  
One Step ◽  
Antigen Tests ◽  
Low Sensitivity ◽  
Antigen Testing

AbstractObjectivesSaliva sampling could serve as an alternative non-invasive sample for SARS-CoV-2 diagnosis while rapid antigen testing (RAT) might help to mitigate the shortage of reagents sporadically encountered with RT-PCR. Thus, in the RESTART study we compared antigen and RT-PCR testing methods on nasopharyngeal (NP) swabs and salivary samples.MethodsWe conducted a prospective observational study among COVID-19 hospitalized patients between 10th December 2020 and 1st February 2021. Paired saliva and NP samples were investigated by RT-PCR (Cobas 6800, Roche-Switzerland) and by two rapid antigen tests: One Step Immunoassay Exdia® COVID-19 Ag (Precision Biosensor, Korea) and Standard Q® COVID-19 Rapid Antigen Test (Roche-Switzerland).ResultsA total of 58 paired NP-saliva specimens were collected. Thirty-two of 58 (55%) patients were hospitalized in the intensive care unit and the median duration of symptoms was 11 days (IQR 5-19). NP and salivary RT-PCR exhibited sensitivity of 98% and 69% respectively whereas the specificity of these RT-PCRs assays were of 100%. NP RAT exhibited much lower diagnostic performances with sensitivities of 35% and 41% for the Standard Q® and Exdia® assays respectively, when a wet-swab approach was used (i.e. when the swab was diluted in the viral transport medium (VTM) before testing). The sensitivity of the dry-swab approach was slightly better (47%). These antigen tests exhibited very low sensitivity (4 and 8%) when applied to salivary swabs.ConclusionsNasopharyngeal RT-PCR is the most accurate test for COVID-19 diagnosis in hospitalized patients. RT-PCR on salivary samples may be used when nasopharyngeal swabs are contraindicated. RAT are not appropriate for hospitalized patients.

scholarly journals An assessment of a rapid SARS-CoV-2 antigen test in Bangladesh

2021 ◽  
Author(s):  
Zannat Kawser ◽  
Mohabbat Hossain ◽  
Sara Suliman ◽  
Shahin Lockman ◽  
Jesse Gitaka ◽  
...  
Keyword(s):  
False Positive ◽  
Rapid Test ◽  
Field Evaluation ◽  
Ease Of Use ◽  
Large Field ◽  
Antigen Test ◽  
Rt Pcr ◽  
Rapid Antigen Detection Test ◽  
Antigen Tests ◽  
Asymptomatic Individuals

Early detection of SARS-CoV-2 infection is crucial to prevent the spread of the virus. In this study, we evaluated the performance of a commercial rapid antigen detection test, BD Veritor, and compared this (and another rapid test, Standard Q) against a gold-standard of nasopharyngeal (NP) swab tested by reverse transcription-polymerase chain reaction (RT-PCR) in prospectively recruited adults in Dhaka, Bangladesh. We compared the sensitivity and specificity of the two rapid antigen tests against RT-PCR results in 130 symptomatic and 130 asymptomatic adults. In addition, we evaluated the suitability and ease-of-use of the BD Veritor test in a subsample of study participants (n=42) and implementers (n=5). The sensitivity of the BD Veritor rapid antigen 66 test was 70% in symptomatic (95% confidence interval [CI]: 51-85%) and 87% (95% CI: 69-96%) in asymptomatic individuals with positive SARSCoV-2 RT-PCR, for overall sensitivity of 78% (95% CI: 66-88%). The sensitivity of the Standard Q rapid antigen test was 63% (95% CI: 44-69 80%) in symptomatic and 73% (95% CI: 54-87%) in asymptomatic individuals. One false positive in BD Veritor test (specificity 99.5) and no false positive in Standard Q tests were observed (specificity 100%). The BD Veritor rapid antigen test was 78% sensitive when compared with RT-PCR irrespective of the cycle threshold (Ct) levels in this evaluation in Bangladesh. The implementation evaluation data showed good acceptability in the field settings. This warrants large field evaluation as well as use of the rapid antigen test for quick assessment of SARS-CoV-2 for containment of epidemics in the country.

The Closed Shop and the National Health Service: A Case Study in Public Sector Labour Relations

1988 ◽  
Vol 17 (1) ◽  
pp. 61-81 ◽  
Author(s):  
Stephen Harrison
Keyword(s):  
National Health Service ◽  
Public Sector ◽  
Health Service ◽  
National Health ◽  
Health Authority ◽  
Trade Unions ◽  
Industrial Relations ◽  
Labour Relations

ABSTRACTDuring the second half of the 1970s, the practice of the closed shop became widespread in some parts of the British public sector, but was resisted in others. This paper examines the issue in relation to the National Health Service, where trade unionists made frequent demands for the closed shop and where many managers were apparently not unwilling to concede it. Yet very few closed shops actually resulted. The paper examines the origin and patterns of these demands, health authority policies towards them, and their outcomes in terms both of the operation of the closed shops which were agreed, and the reasons for failure to agree. The conclusion is that although NHS industrial relations had apparently matured very rapidly between 1973 and 1977, the trade unions were neither strong enough nor united enough to enforce the closed shop; nor were industrial relations so far developed as to make the practice a natural next step.

scholarly journals The Performance of Two Rapid Antigen Tests During Population-Level Screening for SARS-CoV-2 Infection

2021 ◽  
Vol 8 ◽  
Author(s):  
Mohammad Alghounaim ◽  
Hamad Bastaki ◽  
Farah Bin Essa ◽  
Hoda Motlagh ◽  
Salman Al-Sabah
Keyword(s):  
Positive Predictive Value ◽  
Prospective Study ◽  
Predictive Value ◽  
Point Of Care ◽  
Population Level ◽  
Lower Sensitivity ◽  
Rt Pcr ◽  
Antigen Tests ◽  
A Prospective Study ◽  
Antigen Testing

Background: SARS-CoV-2 antigen assays offer a rapid mean to diagnose and isolate infected individuals. However, their utility in population-level screening is unknown.Objectives: The performance of two antigen tests in detecting SARS-CoV-2 was assessed among individuals randomly selected in the community.Study Design: A prospective study that performed head-to-head comparison of two SARS-CoV-2 antigen assays. Individuals were recruited during community SARS-CoV-2 screening over 10 working days. Demographic and clinical data were collected. Standard Q COVID-19 Ag test, a point-of-care chromatographic assay, was conducted immediately, and then the sample was transported to the virology laboratory to perform PCR and the LIAISON SARS-CoV-2 Ag chemiluminesence immunoassay.Results: respiratory samples from 991 individuals were collected, and 62 were positive by PCR. Inconclusive PCR results were observed in 19 samples and were excluded. The median age of participants was 40.2 years (IQR 32.3–47.8), and 932 (94%) were males. Most (77.4%) of infections were asymptomatic. The sensitivity and the specificity of the LIAISON assay were 43.3% (95%CI 30.6–56.8) and 99.9% (95%CI 99.3–100). The Standard Q assay had lower sensitivity (30.6%, 95%CI 19.6–43.7) but similar specificity (98.8%, 95%CI, 97.8–99.4). Similarly, the LIAISON assay had higher positive predictive value (96.3%, 95%CI 81–99.9% vs. 63.3%, 95%CI, 43.9–80.1%). Both assays performed better in symptomatic patients and among samples with a low-cycle threshold (Ct < 25).Conclusion: In our setting of random community surveillance, rapid antigen testing of nasopharyngeal swabs by either LIAISON SARS-CoV-2 Ag (DiaSorin) or Standard Q COVID-19 Ag (SD Biosensor) was less sensitive to detecting SARS-CoV-2 than the TaqPath COVID-19 RT-PCR.

scholarly journals At-home self-testing of teachers with a SARS-CoV-2 rapid antigen test to reduce potential transmissions in schools

2020 ◽  
Author(s):  
Sebastian Hoehl ◽  
Barbara Schenk ◽  
Olga Rudych ◽  
Stephan Göttig ◽  
Ivo Foppa ◽  
...  
Keyword(s):  
False Positive ◽  
High Frequency ◽  
False Negative ◽  
Study Participant ◽  
Lower Sensitivity ◽  
Antigen Test ◽  
Rt Pcr ◽  
Antigen Tests ◽  
Positive Results ◽  
At Home

AbstractBackgroundRapid antigen tests for SARS-CoV-2 became available recently, offering an opportunity to vastly increase testing capacities. Antigen tests offer lower sensitivity than the gold standard, RT-PCR, but rapid sample-to-answer time. High-frequency testing with an antigen test may offset the lower sensitivity, and testing can be done with at-home collection of samples, offering potential benefit in screening efforts. In this study, we set out to evaluate the practical application of self-performed high-frequency antigen test in a school setting.MethodA total of 711 teachers from 86 schools were enrolled in a seven-week study. After instruction, participants tested themselves every 48 hours at home with a rapid antigen test for SARS-CoV-2 (target: nucleocapsid protein) in a self-collected anterior nasal swab. Positive results in the antigen test were confirmed via RT-PCR from the same sample that had been determined to be positive by the study participant. A questionnaire was given to all participants to evaluate whether the test failed to detect infection.Findings10 836 tests from 602 teachers were recorded and analyzed. A total of five confirmed cases of viral shedding of SARS-CoV-2 was detected by use of the antigen test. One study participant with a SARS-CoV-2 infection was presymptomatic and four were mildly symptomatic at the time of the antigen test. Sixteen false positive antigen tests (0.15% of all tests) were reported, predominantly when the local incidence in the general population was low. In four cases, the study participant reported that a PCR had detected a SARS-CoV-2 infection, but the antigen test was negative, indicating a false negative result.InterpretationHigh-frequency, self-performed rapid antigen tests can detect individuals with a SARS-CoV-2 infection, and therefore potentially reduce transmissions. Testing may be most beneficial when applied during high local incidence of SARS-CoV-2 infections and when mild or atypical symptoms are present. To avoid a high rate of false positive results, a test with optimized specificity should be used.FundingThe study was commissioned and funded by the Hessian Ministry of Education and the Hessian Ministry of Integration and Social Affairs.

scholarly journals Five Antigen Tests for SARS-CoV-2: Virus Viability Matters

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 684
Author(s):  
Miroslav Homza ◽  
Hana Zelena ◽  
Jaroslav Janosek ◽  
Hana Tomaskova ◽  
Eduard Jezo ◽  
...  
Keyword(s):  
False Negative ◽  
Antigen Test ◽  
Rt Pcr ◽  
False Negatives ◽  
Predictive Values ◽  
Asymptomatic Patients ◽  
High Prevalence ◽  
Antigen Tests ◽  
Antigen Testing ◽  
Excellent Tool

Antigen testing for SARS-CoV-2 (AGT) is generally considered inferior to RT-PCR testing in terms of sensitivity. However, little is known about the infectiousness of RT-PCR positive patients who pass undetected by AGT. In a screening setting for mildly symptomatic or asymptomatic patients with high COVID-19 prevalence (30–40%), 1141 patients were tested using one of five AGTs and RT-PCR. Where the results differed, virus viability in the samples was tested on cell culture (CV-1 cells). The test battery included AGTs by JOYSBIO, Assure Tech, SD Biosensor, VivaChek Biotech and NDFOS. Sensitivities of the ATGs compared to RT-PCR ranged from 42% to 76%. The best test yielded a 76% sensitivity, 97% specificity, 92% positive, and 89% negative predictive values, respectively. However, in the best performing ATG tests, almost 90% of samples with “false negative” AGT results contained no viable virus. Corrected on the virus viability, sensitivities grew to 81%–97% and, with one exception, the tests yielded high specificities >96%. Performance characteristics of the best test after adjustment were 96% sensitivity, 97% specificity, 92% positive, and 99% negative predictive values (high prevalence population). We, therefore, believe that virus viability should be considered when assessing the AGT performance. Also, our results indicate that a well-performing antigen test could in a high-prevalence setting serve as an excellent tool for identifying patients shedding viable virus. We also propose that the high proportion of RT-PCR-positive samples containing no viable virus in the group of “false negatives” of the antigen test should be further investigated with the aim of possibly preventing needless isolation of such patients.

scholarly journals Surveillance testing for SARS-COV-2 infection in an asymptomatic athlete population: a prospective cohort study with 123 362 tests and 23 463 paired RT-PCR/antigen samples

2021 ◽  
Vol 7 (2) ◽  
pp. e001137
Author(s):  
Kimberly Harmon ◽  
Anabelle M de St Maurice ◽  
Adam C Brady ◽  
Sankar Swaminathan ◽  
Doug F Aukerman ◽  
...  
Keyword(s):  
Screening Programme ◽  
Sports Participation ◽  
High Specificity ◽  
Turnaround Time ◽  
Screening Tests ◽  
Rt Pcr ◽  
Pcr Screening ◽  
Testing Approach ◽  
Antigen Tests ◽  
Antigen Testing

ObjectiveTo assess the diagnostic accuracy of antigen compared with reverse transcriptase (RT)-PCR testing in an asymptomatic athlete screening programme and to monitor infection in college athletes.MethodsQuidel Sofia-2 SARS-CoV-2 Antigen Tests were performed daily before sports participation for football, basketball, wrestling and water polo from 29 September 2020 to 28 February 2021. Paired RT-PCR and antigen tests were performed at least once a week. Positive antigen tests were confirmed with RT-PCR.Results81 175 antigen and 42 187 RT-PCR tests were performed, including 23 462 weekly paired antigen/RT-PCR screening tests in 1931 athletes. One hundred and seventy-two athletes had a positive screening RT-PCR (0.4%), of which 83 (48%) occurred on paired testing days. The sensitivity of antigen tests varied with the frequency of RT-PCR testing and prevalence of COVID-19. The sensitivity of antigen testing was 35.7% (95% CI: 17% to 60%) and specificity 99.8% (95% CI: 99.7% to 99.9%) with once-a-week RT-PCR testing after adjusting for school prevalence. Daily antigen testing was similar to RT-PCR testing two to three times a week in identifying infection. Antigen testing identified infection before the next scheduled PCR on 89 occasions and resulted in 234 days where potentially infectious athletes were isolated before they would have been isolated with RT-PCR testing alone. Two athletic-related outbreaks occurred; 86% of total infections were community acquired.ConclusionAntigen testing has high specificity with a short turnaround time but is not as sensitive as RT-PCR. Daily antigen testing or RT-PCR testing two to three times a week is similar. There are benefits and drawbacks to each testing approach.

scholarly journals The dark side of SARS-CoV-2 rapid antigen testing: screening asymptomatic patients

2021 ◽  
Author(s):  
Giorgia Caruana ◽  
Laure-Line Lebrun ◽  
Oriane Aebischer ◽  
Onya Opota ◽  
Luis Urbano ◽  
...  
Keyword(s):  
Hospital Admissions ◽  
Screening Method ◽  
Dark Side ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Asymptomatic Patients ◽  
Antigen Tests ◽  
Outpatient Settings ◽  
Antigen Testing

AbstractMost of the reports describing SARS-CoV-2 rapid antigen tests (RATs) performances derive from COVID-19 symptomatic subjects in outpatient settings during periods of highest incidence of infections and high rates of hospital admissions. Here we investigated the role of RATs in an Emergency Department, as a screening tool before admission for COVID-19 asymptomatic patients. Each patient was screened with two simultaneous nasopharyngeal swabs: one immediately analyzed at the bedside using RAT and the other sent to the laboratory for RT-PCR analysis. A total of 116 patients were screened at hospital admission in a 250-bed community hospital in Morges (EHC), Switzerland. With a disease prevalence of 6% based on RT-PCR results, RAT detected only two out of seven RT-PCR positive patients (sensitivity 28.6%) and delivered two false positive results (specificity 98.2%), thus resulting not fiable enough to be used as a screening method in this clinical scenario.

scholarly journals Routine antigen testing is not a substitute for healthcare worker vaccination against SARS-CoV-2

2021 ◽  
Author(s):  
Mary Elizabeth Sexton ◽  
Colleen S. Kraft
Keyword(s):  
Diagnostic Accuracy ◽  
Healthcare Worker ◽  
False Positive ◽  
Healthcare Workers ◽  
Clinical Microbiology ◽  
Clinical Situation ◽  
Link Type ◽  
Antigen Tests ◽  
Antigen Testing

The utility of rapid antigen testing for SARS-CoV-2 is measured within the context for which it is applied; diagnostic accuracy must be considered in determining if rapid antigen testing is appropriate for the clinical situation. In this issue of the Journal of Clinical Microbiology , J.N. Kanji et al (J Clin Microbiol 59:e01411-21, 2021, https://doi.org/10.1128/JCM.01411-21 ) evaluate two rapid antigen tests that demonstrate high false-positive rates in asymptomatic healthcare workers. The assays may not be useful in situations where there is a shortage of staff, such as healthcare, since isolation would occur unnecessarily for these employees.

scholarly journals Sensitivity of Rapid Antigen Testing and RT-PCR Performed on Nasopharyngeal Swabs versus Saliva Samples in COVID-19 Hospitalized Patients: Results of a Prospective Comparative Trial (RESTART)

2021 ◽  
Vol 9 (9) ◽  
pp. 1910
Author(s):  
Antonios Kritikos ◽  
Giorgia Caruana ◽  
René Brouillet ◽  
John-Paul Miroz ◽  
Samia Abed-Maillard ◽  
...  
Keyword(s):  
Comparative Trial ◽  
Hospitalized Patients ◽  
Rt Pcr ◽  
Duration Of Symptoms ◽  
Non Invasive ◽  
Viral Transport Medium ◽  
One Step ◽  
Antigen Tests ◽  
Low Sensitivity ◽  
Antigen Testing

Saliva sampling could serve as an alternative non-invasive sample for SARS-CoV-2 diagnosis while rapid antigen tests (RATs) might help to mitigate the shortage of reagents sporadically encountered with RT-PCR. Thus, in the RESTART study we compared antigen and RT-PCR testing methods on nasopharyngeal (NP) swabs and salivary samples. We conducted a prospective observational study among COVID-19 hospitalized patients between 10 December 2020 and 1 February 2021. Paired saliva and NP samples were investigated by RT-PCR (Cobas 6800, Roche-Switzerland, Basel, Switzerland) and by two rapid antigen tests: One Step Immunoassay Exdia® COVID-19 Ag (Precision Biosensor, Daejeon, Korea) and Standard Q® COVID-19 Rapid Antigen Test (Roche-Switzerland). A total of 58 paired NP-saliva specimens were collected. A total of 32 of 58 (55%) patients were hospitalized in the intensive care unit, and the median duration of symptoms was 11 days (IQR 5-19). NP and salivary RT-PCR exhibited sensitivity of 98% and 69% respectively, whereas the specificity of these RT-PCRs assays was 100%. The NP RATs exhibited much lower diagnostic performance, with sensitivities of 35% and 41% for the Standard Q® and Exdia® assays, respectively, when a wet-swab approach was used (i.e., when the swab was diluted in the viral transport medium (VTM) before testing). The sensitivity of the dry-swab approach was slightly better (47%). These antigen tests exhibited very low sensitivity (4% and 8%) when applied to salivary swabs. Nasopharyngeal RT-PCR is the most accurate test for COVID-19 diagnosis in hospitalized patients. RT-PCR on salivary samples may be used when nasopharyngeal swabs are contraindicated. RATs are not appropriate for hospitalized patients.

Sign in / Sign up

Export Citation Format

Share Document