Retrospective analysis of the performance of the SARS-CoV-2 rapid antigen detection test compared to the reference RT-PCR test

Abstract Background The Coronavirus disease 2019 (COVID-19) pandemic continues to spread across the world. Hence, there is an urgent need for rapid, simple, and accurate tests to diagnose severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Performance characteristics of the rapid SARS-CoV-2 antigen detection test should be evaluated and compared with the gold standard real-time reverse transcription-polymerase chain reaction (RT-PCR) test for diagnosis of COVID-19 cases. Methods The rapid SARS-CoV-2 antigen detection test, Standard™ Q COVID-19 Ag kit (SD Biosensor®, Republic of Korea), was compared with the real-time RT-PCR test, Allplex™ 2019-nCoV Assay (Seegene®, Korea) for detection of SARS-CoV-2 in respiratory specimens. Four hundred fifty-four respiratory samples (mainly nasopharyngeal and throat swabs) were obtained from COVID-19 suspected cases and contact individuals, including pre-operative patients at Siriraj Hospital, Bangkok, Thailand during March–May 2020. Results Of 454 respiratory samples, 60 (13.2%) were positive, and 394 (86.8%) were negative for SARS-CoV-2 RNA by real-time RT-PCR assay. The duration from onset to laboratory test in COVID-19 suspected cases and contact individuals ranged from 0 to 14 days with a median of 3 days. The rapid SARS-CoV-2 antigen detection test’s sensitivity and specificity were 98.33% (95% CI, 91.06–99.96%) and 98.73% (95% CI, 97.06–99.59%), respectively. One false negative test result was from a sample with a high real-time RT-PCR cycle threshold (Ct), while five false positive test results were from specimens of pre-operative patients. Conclusions The rapid assay for SARS-CoV-2 antigen detection showed comparable sensitivity and specificity with the real-time RT-PCR assay. Thus, there is a potential use of this rapid and simple SARS-CoV-2 antigen detection test as a screening assay.

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A Rapid Antigen Detection Test to Diagnose SARS-CoV-2 Infection Using Exhaled Breath Condensate by A Modified Inflammacheck® Device

Sensors ◽

10.3390/s21175710 ◽

2021 ◽

Vol 21 (17) ◽

pp. 5710 ◽

Cited By ~ 1

Author(s):

Mauro Maniscalco ◽

Pasquale Ambrosino ◽

Anna Ciullo ◽

Salvatore Fuschillo ◽

Valerio Valente ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Exhaled Breath Condensate ◽

False Negative ◽

Antigen Detection ◽

Routine Practice ◽

Study Cohort ◽

Exhaled Breath ◽

Rt Pcr ◽

Rapid Antigen Detection Test ◽

Breath Condensate

Background: The standard test that identifies the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is based on reverse transcriptase-polymerase chain reaction (RT-PCR) from nasopharyngeal (NP) swab specimens. We compared the accuracy of a rapid antigen detection test using exhaled breath condensate by a modified Inflammacheck® device with the standard RT-PCR to diagnose SARS-CoV-2 infection. Methods: We performed a manufacturer-independent, cross-sectional, diagnostic accuracy study involving two Italian hospitals. Sensitivity, specificity, positive (PLR) and negative likelihood ratio (NLR), positive (PPV) and negative predictive value (NPV) and diagnostic accuracy with 95% confidence intervals (95% CI) of Inflammacheck® were calculated using the RT-PCR results as the standard. Further RT-PCR tests were conducted on NP specimens from test positive subjects to obtain the Ct (cycle threshold) values as indicative evidence of the viral load. Results: A total of 105 individuals (41 females, 39.0%; 64 males, 61.0%; mean age: 58.4 years) were included in the final analysis, with the RT-PCR being positive in 13 (12.4%) and negative in 92 (87.6%). The agreement between the two methods was 98.1%, with a Cohen’s κ score of 0.91 (95% CI: 0.79–1.00). The overall sensitivity and specificity of the Inflammacheck® were 92.3% (95% CI: 64.0%–99.8%) and 98.9% (95% CI: 94.1%–100%), respectively, with a PLR of 84.9 (95% CI: 12.0–600.3) and a NLR of 0.08 (95% CI: 0.01–0.51). Considering a 12.4% disease prevalence in the study cohort, the PPV was 92.3% (95% CI: 62.9%–98.8%) and the NPV was 98.9% (95% CI: 93.3%–99.8%), with an overall accuracy of 98.1% (95% CI: 93.3%–99.8%). The Fagan’s nomogram substantially confirmed the clinical applicability of the test in a realistic scenario with a pre-test probability set at 4%. Ct values obtained for the positive test subjects by means of the RT-PCR were normally distributed between 26 and 38 cycles, corresponding to viral loads from light (38 cycles) to high (26 cycles). The single false negative record had a Ct value of 33, which was close to the mean of the cohort (32.5 cycles). Conclusions: The modified Inflammacheck® device may be a rapid, non-demanding and cost-effective method for SARS-CoV-2 detection. This device may be used for routine practice in different healthcare settings (community, hospital, rehabilitation).

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EVALUATION OF THE PANBIO SARS-COV-2 RAPID ANTIGEN DETECTION TEST IN THE BAHAMAS

10.1101/2021.07.13.21260402 ◽

2021 ◽

Author(s):

Christoph Johnson ◽

Kirvina Ferguson ◽

Tavion Smith ◽

Dashaunette Wallace ◽

Keith McConnell ◽

...

Keyword(s):

Turnaround Time ◽

Antigen Detection ◽

Mitigation Strategies ◽

Threshold Values ◽

Rt Pcr ◽

The Bahamas ◽

Rapid Antigen Detection Test ◽

Test Sensitivity ◽

National Reference ◽

Ct Value

Identification and isolation of persons infected with SARS-COV-2 are key mitigation strategies in the current pandemic, and rapid antigen detection tests (RADTs) offer the promise of decreased turnaround time to diagnosis when compared with gold standard RT-PCR testing. We evaluated the analytical performance of the Abbott Panbio RADT on nasopharyngeal samples stored at the Ministry of Health National Reference Lab in Nassau, Bahamas. The Panbio demonstrated a test sensitivity of 94% and a specificity of 100% on 50 PCR negative samples and 50 samples presumed to be infectious based on having PCR cycle threshold values below 30. Additionally, in our examination of operator results there was low interpersonal variation (1%) among three blind operators and significant correlation between sample Ct value and perceived signal strength on the RADT device. However, three PCR positive samples below Ct 30 were misdiagnosed by RADT, including one sample with Ct value less than 20. These results support the use of the Panbio in symptomatic persons to detect active SARS-COV-2 infections, with the caveat that RADT-negative samples should be confirmed by RT-PCR.

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Accuracy of Rapid Antigen Detection Test for Nasopharyngeal Swab Specimens and Saliva Samples in Comparison with RT-PCR and Viral Culture for SARS-CoV-2 Detection

Journal of Infection and Chemotherapy ◽

10.1016/j.jiac.2021.04.010 ◽

2021 ◽

Author(s):

Yoshifumi Uwamino ◽

Mika Nagata ◽

Wataru Aoki ◽

Terumichi Nakagawa ◽

Rika Inose ◽

...

Keyword(s):

Antigen Detection ◽

Nasopharyngeal Swab ◽

Rt Pcr ◽

Rapid Antigen Detection Test ◽

Viral Culture

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Can a ‘3-tier Screening’ Strategy be Adopted during COVID-19 Pandemic for Safer Air Travel and to Help Curb its Spread Across Borders?

The Open COVID Journal ◽

10.2174/2666958702101010062 ◽

2021 ◽

Vol 1 (1) ◽

pp. 62-64

Author(s):

Mohammad Shahid

Keyword(s):

Detection Method ◽

Screening Strategy ◽

Air Travel ◽

Antigen Detection ◽

Destination Country ◽

Rt Pcr ◽

Screening Protocol ◽

Entire World ◽

Pcr Test

Since the appearance of SARS-CoV-2 in 2019, it spread quickly crossing geographical borders and thus affected almost the entire world. It was alarming to note its quick spread, which obviously was due to the increased frequency and ease of air travel in this era. Currently, many airlines (and countries too) have a prerequisite to have a negative COVID-19 RT-PCR test within 72 hrs. prior to boarding the flight. Although all the necessary precautions are strictly enforced during air travel, there is still a possibility that a person with a negative COVID-19 test (RT-PCR) around 72hrs prior to boarding the flight would have an infection and that the person would pass it on to fellow passengers on board and thus can further spread SARS-CoV-2 infection into the community if robust action is not initiated. There is also a subconscious apprehension among the passengers that co-passengers may have an infection on board. This is especially worrisome seeing the appearance of new variants recently. Here I present the logistics for a ‘3-tier screening’ protocol (1st test by RT-PCR within 72hrs of the flight schedule, 2nd test by rapid antigen detection method 1-5hrs prior to flight schedule, 3rd test post-arrival or to follow the destination country post-arrival protocol), which would at least provide an extra filter to separate the recently identified positive cases and thus prevent the spread of this threatening disease across the borders.

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A comparative study: Results of rapid antigen detection assay and real time RT-PCR for diagnosis of COVID-19 in a tertiary care hospital

10.17727/jmsr.2020/8s1-4 ◽

2020 ◽

Vol 8 (S1) ◽

pp. 33-40

Author(s):

Banerjee J ◽

Reddy SG ◽

Darapuneni RC ◽

Bilolikar AK

Keyword(s):

Real Time ◽

Tertiary Care ◽

Antigen Detection ◽

Diagnostic Tools ◽

Nasopharyngeal Swab ◽

Care Hospital ◽

Rt Pcr ◽

Rapid Antigen Detection Test ◽

Detection Assay ◽

Study Results

Introduction: December 2019, witnessed the emergence of a novel coronavirus in human population. Later named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has since spread across the globe and results into coronavirus disease 2019 (COVID-19) pandemic. Objective: The objective of this study was to evaluate COVID-19 infection positivity rate, its age and gender wise prevalence and to compare the results of rapid antigen detection test with gold standard real time RT-PCR for early detection of SARS-CoV-2 virus. Methods: An observational study was conducted in the Department of Microbiology and Molecular Biology of Krishna Institute of Medical Sciences, Secunderabad, Telangana. Results: A total of 208 patients’ specimens (nasopharyngeal swab) were compared within a period of one and half month. Infection positivity rate was observed as 26.92% (n=56). Our study revealed that among all 56 COVID-19 positive patients, 60.71% (n=34) were symptomatic whereas 39.2% (n=22) were asymptomatic. Conclusion: We conclude that after comparing with real time RT-PCR, antigen detection assay is not as sensitive as molecular test especially during the early stages of infection but this has potential to become an important tool for mass screening for COVID-19 and can be considered as fast and economic diagnostic tools in the remote areas where the laboratory facilities for molecular tests are not accessible. Keywords: COVID-19; pandemic; nasopharyngeal swab; rapid antigen detection assay; real time RT-PCR

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Evaluation of three rapid lateral flow antigen detection tests for the diagnosis of SARS-CoV-2 infection

10.1101/2020.12.30.20249057 ◽

2021 ◽

Author(s):

AE Jääskeläinen ◽

MJ Ahava ◽

P Jokela ◽

L Szirovicza ◽

S Pohjala ◽

...

Keyword(s):

High Viral Load ◽

Antigen Detection ◽

Diagnostic Tools ◽

Repeated Testing ◽

Rt Pcr ◽

High Demand ◽

Overall Performance ◽

Virus Culture ◽

Regulatory Acceptance ◽

Pcr Test

AbstractIntroductionThe COVID-19 pandemic has led to high demand of diagnostic tools. Rapid antigen detection tests have been developed and many have received regulatory acceptance such as CE IVD or FDA markings. Their performance needs to be carefully assessed.Materials and Methods158 positive and 40 negative retrospective samples collected in saline and analyzed by a laboratory-developed RT-PCR test were used to evaluate Sofia (Quidel), Standard Q (SD Biosensor), and Panbio™ (Abbott) rapid antigen detection tests (RADTs). A subset of the specimens was subjected to virus culture.ResultsThe specificity of all RADTs was 100% and the sensitivity and percent agreement was 80% and 85% for Sofia, 81% and 85% for Standard Q, and 83% and 86% for Panbio™, respectively. All three RADTs evaluated in this study reached a more than 90% sensitivity for samples with a high viral load as estimated from the low Ct values in the reference RT-PCR. Virus culture was successful in 80% of specimens with a Ct value <25.ConclusionsAs expected, the RADTs were less sensitive than RT-PCR. However, they benefit from the speed and ease of testing, and lower price as compared to RT-PCR. Repeated testing in appropriate settings may improve the overall performance.

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Superiority of MALDI-TOF Mass Spectrometry over Real-Time PCR for SARS-CoV-2 RNA Detection

Viruses ◽

10.3390/v13050730 ◽

2021 ◽

Vol 13 (5) ◽

pp. 730

Author(s):

Magda Rybicka ◽

Ewa Miłosz ◽

Krzysztof Piotr Bielawski

Keyword(s):

Mass Spectrometry ◽

Gold Standard ◽

Viral Genome ◽

False Negative ◽

Rt Pcr ◽

Rna Detection ◽

Maldi Tof ◽

Negative Results ◽

False Negative Results ◽

Pcr Test

At present, the RT-PCR test remains the gold standard for early diagnosis of SARS-CoV-2. Nevertheless, there is growing evidence demonstrating that this technique may generate false-negative results. Here, we aimed to compare the new mass spectrometry-based assay MassARRAY® SARS-CoV-2 Panel with the RT-PCR diagnostic test approved for clinical use. The study group consisted of 168 suspected patients with symptoms of a respiratory infection. After simultaneous analysis by RT-PCR and mass spectrometry methods, we obtained discordant results for 17 samples (10.12%). Within fifteen samples officially reported as presumptive positive, 13 were positive according to the MS-based assay. Moreover, four samples reported by the officially approved RT-PCR as negative were positive in at least one MS assay. We have successfully demonstrated superior sensitivity of the MS-based assay in SARS-CoV-2 detection, showing that MALDI-TOF MS seems to be ideal for the detection as well as discrimination of mutations within the viral genome.

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The role of CT imaging for management of COVID-19 in epidemic area: early experience from a University Hospital

Insights into Imaging ◽

10.1186/s13244-020-00957-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Vikram rao Bollineni ◽

Koenraad Hans Nieboer ◽

Seema Döring ◽

Nico Buls ◽

Johan de Mey

Keyword(s):

Ct Scan ◽

Predictive Value ◽

Ct Imaging ◽

Chest Ct ◽

University Hospital ◽

Rt Pcr ◽

Ct Findings ◽

Epidemic Area ◽

Chest Ct Scan ◽

Pcr Test

Abstract Background To evaluate the clinical value of the chest CT scan compared to the reference standard real-time polymerase chain reaction (RT-PCR) in COVID-19 patients. Methods From March 29th to April 15th of 2020, a total of 240 patients with respiratory distress underwent both a low-dose chest CT scan and RT-PCR tests. The performance of chest CT in diagnosing COVID-19 was assessed with reference to the RT-PCR result. Two board-certified radiologists (mean 24 years of experience chest CT), blinded for the RT-PCR result, reviewed all scans and decided positive or negative chest CT findings by consensus. Results Out of 240 patients, 60% (144/240) had positive RT-PCR results and 89% (213/240) had a positive chest CT scans. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of chest CT in suggesting COVID-19 were 100% (95% CI: 97–100%, 144/240), 28% (95% CI: 19–38%, 27/240), 68% (95% CI: 65–70%) and 100%, respectively. The diagnostic accuracy of the chest CT suggesting COVID-19 was 71% (95% CI: 65–77%). Thirty-three patients with positive chest CT scan and negative RT-PCR test at baseline underwent repeat RT-PCR assay. In this subgroup, 21.2% (7/33) cases became RT-PCR positive. Conclusion Chest CT imaging has high sensitivity and high NPV for diagnosing COVID-19 and can be considered as an alternative primary screening tool for COVID-19 in epidemic areas. In addition, a negative RT-PCR test, but positive CT findings can still be suggestive of COVID-19 infection.

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Delayed pulmonary embolism after COVID-19 pneumonia: a case report

European Heart Journal - Case Reports ◽

10.1093/ehjcr/ytaa449 ◽

2020 ◽

Author(s):

Mohamad Kanso ◽

Thomas Cardi ◽

Halim Marzak ◽

Alexandre Schatz ◽

Loïc Faucher ◽

...

Keyword(s):

Risk Factors ◽

Intensive Care Unit ◽

Pulmonary Embolism ◽

Acute Pulmonary Embolism ◽

Index Hospitalization ◽

Rt Pcr ◽

Moderate Severity ◽

Respiratory Status ◽

Case Summary ◽

Pcr Test

Abstract Background Since the onset of the COVID-19 pandemic, several cardiovascular manifestations have been described. Among them, venous thromboembolism (VTE) seems to be one of the most frequent, particularly in intensive care unit patients. We report two cases of COVID-19 patients developing acute pulmonary embolism (PE) after discharge from a first hospitalization for pneumonia of moderate severity. Case summary Two patients with positive RT-PCR test were initially hospitalized for non-severe COVID-19. Both received standard thromboprophylaxis during the index hospitalization and had no strong predisposing risk factors for VTE. Few days after discharge, they were both readmitted for worsening dyspnoea due to PE. One patient was positive for lupus anticoagulant. Discussion Worsening respiratory status in COVID-19 patients must encourage physicians to search for PE since SARS-CoV-2 infection may act as a precipitant risk factor for VTE. Patients may thus require more aggressive and longer thromboprophylaxis after COVID-19 related hospitalization.

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