Clinical assessment of the Roche SARS-CoV-2 rapid antigen test

Abstract Objectives Novel point-of-care antigen assays present a promising opportunity for rapid screening of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. The purpose of this study was the clinical assessment of the new Roche SARS-CoV-2 Rapid Antigen Test. Methods The clinical performance of Roche SARS-CoV-2 Rapid Antigen Test was evaluated vs. a reverse transcription polymerase chain reaction (RT-PCR) laboratory-based assay (Seegene AllplexTM2019-nCoV) in nasopharyngeal swabs collected from a series of consecutive patients referred for SARS-CoV-2 diagnostics to the Pederzoli Hospital (Peschiera del Garda, Verona, Italy) over a 2-week period. Results The final study population consisted of 321 consecutive patients (mean age, 46 years and IQR, 32–56 years; 181 women, 56.4%), with 149/321 (46.4%) positive for SARS-CoV-2 RNA via the Seegene AllplexTM2019-nCoV Assay, and 109/321 (34.0%) positive with Roche SARS-CoV-2 Rapid Antigen Test, respectively. The overall accuracy of Roche SARS-CoV-2 Rapid Antigen Test compared to molecular testing was 86.9%, with 72.5% sensitivity and 99.4% specificity. Progressive decline in performance was observed as cycle threshold (Ct) values of different SARS-CoV-2 gene targets increased. The sensitivity was found to range between 97–100% in clinical samples with Ct values <25, between 50–81% in those with Ct values between 25 and <30, but low as 12–18% in samples with Ct values between 30 and <37. Conclusions The clinical performance of Roche SARS-CoV-2 Rapid Antigen Test is excellent in nasopharyngeal swabs with Ct values <25, which makes it a reliable screening test in patients with high viral load. However, mass community screening would require the use of more sensitive techniques.

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Clinical performance evaluation of SARS-CoV-2 rapid antigen testing in point of care usage in comparison to RT-qPCR

10.1101/2021.03.27.21253966 ◽

2021 ◽

Author(s):

Isabell Wagenhaeuser ◽

Kerstin Knies ◽

Vera Rauschenberger ◽

Michael Eisenmann ◽

Miriam McDonogh ◽

...

Keyword(s):

Performance Evaluation ◽

Viral Load ◽

Clinical Performance ◽

Point Of Care ◽

Hospital Setting ◽

High Viral Load ◽

Evaluation Study ◽

Study Cohort ◽

Protein Variant ◽

Atypical Symptoms

Background Antigen rapid diagnostic tests (RDT) for SARS-CoV-2 are fast, broadly available, and inexpensive. Despite this, reliable clinical performance data is sparse. Methods In a prospective performance evaluation study, RDT from three manufacturers (NADAL, Panbio, MEDsan) were compared to quantitative reverse transcription polymerase chain reaction (RT-qPCR) in 5 068 oropharyngeal swabs for detection of SARS-CoV-2 in a hospital setting. Viral load was derived from standardized RT-qPCR Cycle threshold (Ct) values. The data collection period ranged from November 12, 2020 to February 28, 2021. Findings Overall, sensitivity of RDT compared to RT-qPCR was 42.57% (95% CI 33.38%-52.31%), and specificity 99.68% (95% CI 99.48%-99.80%). Sensitivity declined with decreasing viral load from 100% in samples with a deduced viral load of 10^8 SARS-CoV-2 RNA copies per ml to 8.82% in samples with a viral load lower than 104 SARS-CoV-2 RNA copies per ml. No significant differences in sensitivity or specificity could be observed between the three manufacturers, or between samples with and without spike protein variant B.1.1.7. The NPV in the study cohort was 98.84%; the PPV in persons with typical COVID-19 symptoms was 97.37%, and 28.57% in persons without or with atypical symptoms. Interpretation RDT are a reliable method to diagnose SARS-CoV-2 infection in persons with high viral load. RDT are a valuable addition to RT-qPCR testing, as they reliably detect infectious persons with high viral loads before RT-qPCR results are available. Funding German Federal Ministry for Education and Science (BMBF), Free State of Bavaria

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Clinical Performance of Mycobacterial Immunohistochemistry in Anatomic Pathology Specimens

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqaa119 ◽

2020 ◽

Vol 155 (1) ◽

pp. 97-105

Author(s):

Jessica W Crothers ◽

Alvaro C Laga ◽

Isaac H Solomon

Keyword(s):

Potential Role ◽

Clinical Performance ◽

Rapid Screening ◽

Molecular Testing ◽

Mycobacterial Infections ◽

Anatomic Pathology ◽

Comparable Performance ◽

Rapid Screening Test ◽

Polymerase Chain ◽

Better Than

Abstract Objectives Diagnosis of mycobacterial infections poses significant challenges in anatomic pathology. We recently described the use of antimycobacteria immunohistochemistry (IHC) as a sensitive, efficient diagnostic tool and now report the clinical performance of this assay among general, noninfectious disease pathology-trained anatomic pathologists. Methods Over a 2-year period, all cases were retrospectively identified in which mycobacterial IHC was performed during routine diagnostic workup. Results From October 2017 to September 2019, mycobacterial IHC was evaluated for 267 cases, resulting in 58 (22%) positive stains. Compared with culture and molecular results, the sensitivity and specificity of IHC were 52% and 80%, respectively. IHC performed significantly better than acid-fast bacilli (AFB) staining (Ziehl-Neelsen) (P < .0001; sensitivity 21%, specificity 92%) but similarly to modified AFB staining (mAFB; Fite-Faraco) (P = .9; sensitivity 61%, specificity 84%). In cases with discordant IHC and mAFB staining, there were no differences in rates of culture or polymerase chain reaction–confirmed positivity. Conclusions Mycobacterial IHC was well adopted with superior clinical performance to AFB and comparable performance to mAFB. These results support the use of IHC as an adjunctive tool in the diagnosis of mycobacterial infections and suggests its potential role as a rapid screening test for molecular testing.

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Highly performing point-of-care molecular testing for SARS-CoV-2 with RNA extraction and isothermal amplification.

10.1101/2020.08.01.20166538 ◽

2020 ◽

Author(s):

Pierre Garneret ◽

Etienne Coz ◽

Elian Martin ◽

Jean-Claude Manuguerra ◽

Elodie Brient-Litzler ◽

...

Keyword(s):

Point Of Care ◽

Low Cost ◽

Rna Extraction ◽

Dna Amplification ◽

Developed Countries ◽

Temperature Cycling ◽

Isothermal Amplification ◽

Nucleic Acid Amplification ◽

Clinical Samples ◽

Molecular Testing

In order to respond to the urgent request of massive testing, developed countries perform nucleic acid amplification tests (NAAT) of SARS-CoV-2 in centralized laboratories. Real-time RT - PCR (Reverse transcription - Polymerase Chain Reaction) is used to amplify the viral RNA and enable its detection. Although PCR is 37 years old, it is still considered, without dispute, as the gold standard. PCR is an efficient process, but the complex engineering required for automated RNA extraction and temperature cycling makes it incompatible for use in point of care settings. In the present work, by harnessing progress made in the past two decades in DNA amplification, microfluidics and membrane technologies, we succeeded to create a portable test, in which SARS-CoV-2 RNA is extracted, amplified isothermally by RT - LAMP (Loop-mediated Isothermal Amplification), and detected using intercalating dyes or highly fluorescent probes. Depending on the viral load, the detection takes between twenty minutes and one hour. Using pools of naso-pharyngal clinical samples, we estimated a sensitivity comparable to RT-qPCR (up to a Cycle threshold of 39, equivalent to <0.1 TCID50 per mL) and a 100% specificity, for other human coronaviruses and eight respiratory viruses currently circulating in Europe. We designed and fabricated an easy-to-use portable device called COVIDISC to carry out the test at the point of care. The low cost of the materials along with the absence of complex equipment paves the way towards a large dissemination of this device. The perspective of a reliable SARS-CoV-2 point of care detection, highly performing, that would deliver on-site results in less than one hour opens up a new efficient approach to manage the pandemics.

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Clinical performance of the point-of-care cobas Liat for detection of SARS-CoV-2 in 20 minutes: A multicenter study

Journal of Clinical Microbiology ◽

10.1128/jcm.02811-20 ◽

2020 ◽

Author(s):

Glen Hansen ◽

Jamie Marino ◽

Zi-Xuan Wang ◽

Kathleen G. Beavis ◽

John Rodrigo ◽

...

Keyword(s):

Influenza A ◽

Clinical Performance ◽

Point Of Care ◽

Nasopharyngeal Swab ◽

Molecular Testing ◽

Rt Pcr ◽

Percent Agreement ◽

Individual Care ◽

Pcr Technology ◽

Acid Test

Background: Highly accurate testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the point of care (POC) is an unmet diagnostic need in emergency care and time-sensitive outpatient care settings. Reverse transcription-polymerase chain reaction (RT-PCR) technology is the gold-standard for SARS-CoV-2 diagnostics. Methods: We performed a multi-site United States (US) study comparing the clinical performance of the first US Food and Drug Administration (FDA) authorized POC RT-PCR test for detection of SARS-CoV-2 in 20 minutes, the cobas® Liat SARS-CoV-2 & Influenza A/B nucleic acid test, to the most widely used RT-PCR laboratory test, the cobas® 68/8800 SARS-CoV-2 test. Results: Clinical nasopharyngeal swab specimens from 444 patients with 357 evaluable specimens at five US clinical laboratories were enrolled from September 21, 2020 to October 23, 2020. The overall agreement between the Liat and 68/8800 systems for SARS-CoV-2 diagnostics was 98.6% (352/357). Using Liat, positive percent agreement for SARS-CoV-2 was 100% (162/162) and the negative percent agreement was 97.4% (190/195). Conclusion: The Liat is an RT-PCR POC test that provides highly accurate SARS-CoV-2 results in 20 minutes with equivalent performance to high-throughput laboratory molecular testing. Rapid RT-PCR testing at the POC can enable more timely infection control and individual care decisions for Coronavirus Disease 2019.

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Clinical Evaluation of the Novel Rapid Nucleic Acid Amplification Point-of-Care Test (Smart Gene SARS-CoV-2) in the analysis of Nasopharyngeal and Anterior Nasal samples.

10.1101/2021.08.25.21262583 ◽

2021 ◽

Author(s):

Yoshihiko Kiyasu ◽

Masato Owaku ◽

Yusaku Akashi ◽

Yuto Takeuchi ◽

Kenji Narahara ◽

...

Keyword(s):

Real Time ◽

Clinical Performance ◽

Point Of Care ◽

Nucleic Acid Amplification ◽

Molecular Testing ◽

The Novel ◽

Rt Pcr ◽

Pcr Assay ◽

Point Of Care Test ◽

Hands On

Introduction Smart Gene is a point-of-care (POC)-type automated molecular testing platform that can be performed with 1 minute of hands-on-time. Smart Gene SARS-CoV-2 is a newly developed Smart Gene molecular assay for the detection of SARS-CoV-2. The analytical and clinical performance of Smart Gene SARS-CoV-2 has not been evaluated. Methods Nasopharyngeal and anterior nasal samples were prospectively collected from subjects referred to the local PCR center from March 25 to July 5, 2021. Two swabs were simultaneously obtained for the Smart Gene SARS-CoV-2 assay and the reference real-time RT-PCR assay, and the results of Smart Gene SARS-CoV-2 were compared to the reference real-time RT-PCR assay. Results Among a total of 1150 samples, 68 of 791 nasopharyngeal samples and 51 of 359 anterior nasal samples were positive for SARS-CoV-2 in the reference real-time RT-PCR assay. In the testing of nasopharyngeal samples, Smart Gene SARS-CoV-2 showed the total, positive and negative concordance of 99.2% (95% confidence interval [CI]: 98.4–99.7%), 94.1% (95% CI: 85.6–98.4%) and 99.7% (95% CI: 99.0–100%), respectively. For anterior nasal samples, Smart Gene SARS-CoV-2 showed the total, positive and negative concordance of 98.9% (95% CI: 97.2–99.7%), 98.0% (95% CI: 89.6–100%) and 99.0% (95% CI: 97.2–99.8%), respectively. In total, 5 samples were positive in the reference real-time RT-PCR and negative in Smart Gene SARS-CoV-2, whereas 5 samples were negative in the reference real-time RT-PCR and positive in Smart Gene SARS-CoV-2. Conclusion Smart Gene SARS-CoV-2 showed sufficient analytical performance for the detection of SARS-CoV-2 in nasopharyngeal and anterior nasal samples.

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Salivary SARS-CoV-2 antigen rapid detection: a prospective cohort study

10.1101/2020.12.24.20248825 ◽

2020 ◽

Author(s):

Daniela Basso ◽

Ada Aita ◽

Andrea Padoan ◽

Chiara Cosma ◽

Filippo Navaglia ◽

...

Keyword(s):

Symptom Onset ◽

Point Of Care ◽

High Viral Load ◽

Antigen Detection ◽

Molecular Testing ◽

Pharyngeal Swab ◽

Viral Loads ◽

Optimal Value ◽

Antigen Testing ◽

Limited Sensitivity

AbstractBackgroundSARS-CoV-2 quick testing and reporting are now considered relevant for the containment of new pandemic waves. Antigen testing in self-collected saliva might be useful. We compared the diagnostic performance of salivary and naso-pharyngeal swab (NPS) SARS-CoV-2 antigen detection by a rapid chemiluminescent assay (CLEIA) and two different point-of-care (POC) immunochromatographic assays, with that of molecular testing.Methods234 patients were prospectively enrolled. Paired self-collected saliva (Salivette) and NPS were obtained to perform rRT-PCR, chemiluminescent (Lumipulse G) and POC (NPS: Fujirebio and Abbott; saliva: Fujirebio) for SARS-CoV-2 antigen detection.ResultsThe overall agreement between NPS and saliva rRT-PCR was 78.7%, reaching 91.7% at the first week from symptoms onset. SARS-CoV-2 CLEIA antigen was highly accurate in distinguishing between positive and negative NPS (ROC-AUC=0.939, 95%CI:0.903-0.977), with 81.6% sensitivity and 93.8% specificity. This assay on saliva had an overall good accuracy (ROC-AUC=0.805, 95%CI:0.740-0.870), reaching the optimal value within 7 days from symptom onset (Sensitivity: 72%; Specificity: 97%). POC antigen in saliva had a very limited sensitivity (13%), performing better in NPS (Sensitivity: 48% and 66%; Specificity: 100% and 99% for Espline and Abbott respectively), depending on viral loads.ConclusionsSelf-collected saliva is a valid alternative to NPS for SARS-CoV-2 detection not only by molecular, but also by CLEIA antigen testing, for which the highest diagnostic accuracy was achieved in the first week from symptom onset. Saliva is not suitable for POC, although the accuracy of these tests appears satisfactory for NPS with high viral load.

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Rapid and sensitive point-of-care detection of Leptospira by RPA-CRISPR/Cas12a targeting lipL32

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0010112 ◽

2022 ◽

Vol 16 (1) ◽

pp. e0010112

Author(s):

Sirawit Jirawannaporn ◽

Umaporn Limothai ◽

Sasipha Tachaboon ◽

Janejira Dinhuzen ◽

Patcharakorn Kiatamornrak ◽

...

Keyword(s):

Limit Of Detection ◽

Clinical Performance ◽

Point Of Care ◽

Limited Resource ◽

Cross Reactivity ◽

Clinical Samples ◽

Detection Assay ◽

Short Palindromic Repeat ◽

Flow Detection ◽

Point Of Care Detection

Background One of the key barriers preventing rapid diagnosis of leptospirosis is the lack of available sensitive point-of-care testing. This study aimed to develop and validate a clustered regularly-interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 12a (CRISPR/Cas12a) platform combined with isothermal amplification to detect leptospires from extracted patient DNA samples. Methodology/Principal findings A Recombinase Polymerase Amplification (RPA)-CRISPR/Cas12a-fluorescence assay was designed to detect the lipL32 gene of pathogenic Leptospira spp. The assays demonstrated a limit of detection (LOD) of 100 cells/mL, with no cross-reactivity against several other acute febrile illnesses. The clinical performance of the assay was validated with DNA extracted from 110 clinical specimens and then compared to results from qPCR detection of Leptospira spp. The RPA-CRISPR/Cas12a assay showed 85.2% sensitivity, 100% specificity, and 92.7% accuracy. The sensitivity increased on days 4–6 after the fever onset and decreased after day 7. The specificity was consistent for several days after the onset of fever. The overall performance of the RPA-CRISPR/Cas12a platform was better than the commercial rapid diagnostic test (RDT). We also developed a lateral flow detection assay (LFDA) combined with RPA-CRISPR/Cas12a to make the test more accessible and easier to interpret. The combined LFDA showed a similar LOD of 100 cells/mL and could correctly distinguish between known positive and negative clinical samples in a pilot study. Conclusions/Significance The RPA-CRISPR/Cas12 targeting the lipL32 gene demonstrated acceptable sensitivity and excellent specificity for detection of leptospires. This assay might be an appropriate test for acute leptospirosis screening in limited-resource settings.

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Clinical evaluation of rapid point of care antigen tests for diagnosis of SARS-CoV-2 infection

10.21203/rs.3.rs-176725/v1 ◽

2021 ◽

Author(s):

Johannes G.M. Koeleman ◽

Henk Brand ◽

Stijn J. de Man ◽

David Ong

Keyword(s):

Clinical Performance ◽

Point Of Care ◽

Rapid Identification ◽

Antigen Test ◽

Large Variability ◽

Clinical Sensitivity ◽

Nursing Home Patients ◽

Upper Respiratory ◽

Antigen Tests ◽

Respiratory Specimens

Abstract Purpose: The 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 diagnosed COVID-19 patients to be treated and isolated immediately. Rapid antigen tests could overcome this problem and therefore a large number of COVID-19 rapid antigen tests have been developed. Methods: In this study clinical performances of five rapid antigen tests were compared to RT-qPCR in upper respiratory specimens from 80 patients. In addition, the rapid antigen test with the best test characteristics (Romed) was evaluated in a large prospective collection of randomly selected upper respiratory specimens from 900 different COVID-19 suspected patients (300 emergency room patients, 300 nursing home patients and 300 health care workers) in the period from October 24 to November 15, 2020. Results: Overall specificity was almost 100% and sensitivity ranged 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 groups varied from 65.3% to 86.7%. Sensitivity was highest in patients with short-term symptoms. In a population with a COVID-19 prevalence of 1% the negative predictive value in all patients was 99.7%. Conclusion: 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, which makes this antigen test suitable for rapid identification of COVID-19 infected patients.

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Evaluation of a SARS-CoV-2 rapid antigen test: potential to help reduce community spread?

10.1101/2020.12.04.20240283 ◽

2020 ◽

Cited By ~ 1

Author(s):

Tuna Toptan ◽

Lisa Eckermann ◽

Annika E. Pfeiffer ◽

Sebastian Hoehl ◽

Sandra Ciesek ◽

...

Keyword(s):

Cell Culture ◽

Clinical Performance ◽

Cross Reactivity ◽

Clinical Samples ◽

Antigen Test ◽

Rigorous Analysis ◽

Viral Loads ◽

Test Sensitivity ◽

Antigen Tests ◽

Asymptomatic Individuals

ABSTRACTSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can spread from symptomatic patients with COVID-19, but also from asymptomatic individuals. Therefore, robust surveillance and timely interventions are essential for the control of virus spread within the community. In this regard the frequency of testing and speed of reporting, but not the test sensitivity alone, play a crucial role. In order to reduce the costs and meet the expanding demands in real-time RT-PCR (rRT-PCR) testing for SARS-CoV-2, complementary assays, such as rapid antigen tests, have been developed. Rigorous analysis under varying conditions is required to assess the clinical performance of these tests and to ensure reproducible results. We evaluated the sensitivity and specificity of a recently licensed rapid antigen test using 137 clinical samples in two institutions. Test sensitivity was between 88.2-89.6% when applied to samples with viral loads typically seen in infectious patients. Of 32 rRT-PCR positive samples, 19 demonstrated infectivity in cell culture, and 84% of these samples were reactive with the antigen test. Seven full-genome sequenced SARS-CoV-2 isolates and SARS-CoV-1 were detected with this antigen test, with no cross-reactivity against other common respiratory viruses. Numerous antigen tests are available for SARS-CoV-2 testing and their performance to detect infectious individuals may vary. Head-to-head comparison along with cell culture testing for infectivity may prove useful to identify better performing antigen tests. The antigen test analyzed in this study is easy-to-use, inexpensive, and scalable. It can be helpful in monitoring infection trends and thus has potential to reduce transmission.

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