Comparing the diagnostic accuracy of point-of-care lateral flow antigen testing for SARS-CoV-2 with RT-PCR in primary care (REAP-2)

While molecular testing with real-time polymerase chain reaction (RT-PCR) remains the gold-standard test for COVID-19 diagnosis and screening, more rapid or affordable molecular and antigen testing options have been developed. More affordable, point-of-care antigen testing, despite being less sensitive compared to molecular assays, might be preferable for wider screening initiatives. Simple laboratory, imaging and clinical parameters could facilitate prognostication and triage. This comprehensive review summarises current evidence on the diagnostic, screening and prognostic tests for COVID-19.

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Point-Of-Care Clinical Evaluation of the Clungene® SARS-CoV-2 Virus IgG/IgM 15-minute rapid test cassette with the Cobas® Roche RT-PCR platform in patients with or without Covid-19

LymphoSign Journal ◽

10.14785/lymphosign-2021-0017 ◽

2021 ◽

Author(s):

Fadi Haddad ◽

Christopher C Lamb ◽

Ravina Kullar ◽

George Sakoulas

Keyword(s):

Symptom Onset ◽

Serological Test ◽

Point Of Care ◽

Diagnostic Testing ◽

Rapid Test ◽

Lateral Flow ◽

Added Value ◽

Lateral Flow Immunoassay ◽

Rt Pcr ◽

Past Infection

Background: Covid-19 remains a pandemic with multiple challenges to confirm patient infectivity: lack of sufficient tests, accurate results, validated quality, and timeliness of results. We hypothesize that a rapid 15-minute Point-Of-Care serological test to evaluate past infection complements diagnostic testing for Covid-19 and significantly enhances testing availability. Method: A three arm observational study at Sharp Healthcare, San Diego, California was conducted using the Clungene® lateral flow immunoassay (LFI) and compared with the Cobas® Roche RT PCR results. Arm 1: Thirty-five (35) subjects with confirmed Covid-19 using RT-PCR were tested twice: prior to 14 days following symptom onset and once between 12 and 70 days. Arm 2: Thirty (30) subjects with confirmed Covid-19 using RT-PCR were tested 12-70 days post symptom onset. Arm 3: Thirty (30) subjects with a negative RT-PCR for Covid-19 were tested 1-10 days following the RT-PCR test date. Results: Specificity of confirmed negative Covid-19 by RT-PCR was 100% (95% CI, 88.4%-100.0%); meaning there was 100% negative positive agreement between the RT-PCR and the Clungene® serological test results. Covid-19 subjects tested prior to day 7 symptom onset were antibody negative. In subjects 7-12 days following symptom onset with a confirmed positive Covid-19 by RT-PCR, the combined sensitivity of IgM and IgG was 58.6% (95% CI, 38.9%-76.5%). In subjects 13-70 days following symptom onset with a confirmed positive Covid-19 by RT-PCR the combined sensitivity of IgM and IgG was 90.5% (95% CI, 80.4%-96.4%). Conclusion: The Clungene® lateral flow immunoassay (LFI) is a useful tool to confirm individuals with an adaptive immune response to SARS-CoV-2 indicating past infection. Providing Point-Of-Care results within 15 minutes without any laboratory instrumentation or specialized software has an added value of increasing test availability to patients who have been symptomatic for more than one week to confirm past infection. Performance characteristics are optimal after 13 days with a sensitivity and specificity of 90% and 100%, respectively.

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Diagnostic accuracy estimates for COVID-19 RT-PCR and Lateral flow immunoassay tests with Bayesian latent class models

10.21203/rs.3.rs-33243/v1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Polychronis Kostoulas ◽

Paolo Eusebi ◽

Sonja Hartnack

Keyword(s):

Diagnostic Accuracy ◽

Symptom Onset ◽

Latent Class ◽

Reference Method ◽

Latent Class Models ◽

Lateral Flow ◽

Lateral Flow Immunoassay ◽

Rt Pcr ◽

The Cross ◽

Class Models

Abstract The objective of this work was to estimate the diagnostic accuracy of RT-PCR and Lateral flow immunoassay tests (LFIA) for COVID-19, depending on the time post symptom onset. Based on the cross-classified results of RT-PCR and LFIA, we used Bayesian latent class models (BLCMs), which do not require a gold standard for the evaluation of diagnostics. Data were extracted from studies that evaluated LFIA (IgG and/or IgM) assays using RT-PCR as the reference method. The cross-classified results of LFIA and RT-PCR were analysed separately for the first, second and third week post symptom onset. The SeRT-PCR was 0.695 (95% probability intervals: 0.563; 0.837) for the first week and remained similar for the second and the third week. The SeIgG/M was 0.318 (0.229; 0.416) for the first week and increased steadily. It was 0.755 (0.673; 0.829) and 0.927 (0.881; 0.965) for the second and third week, respectively. Both tests had a high to absolute Sp, with point median estimates for SpRT-PCR being consistently higher. SpRT-PCR was 0.990 (0.980; 0.998) for the first week. The corresponding value for SpIgG/M was 0.962 (0.905; 0.998). Further, Sp estimates for each test did not differ between weeks. BLCMs provide a valid and efficient alternative for evaluating the rapidly evolving diagnostics for COVID-19, under various clinical settings and for different risk profiles.

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Clinical validation of a point-of-care antibody test for COVID-19

10.1101/2020.12.16.20248303 ◽

2020 ◽

Author(s):

Monila Patel ◽

Yogesh Lakhotia ◽

Sneha Shah ◽

Nilay Suthar ◽

Cherry Shah ◽

...

Keyword(s):

Confidence Interval ◽

Sensitivity And Specificity ◽

Significant Role ◽

Point Of Care ◽

Antibody Test ◽

Lateral Flow ◽

Clinical Validation ◽

Rt Pcr ◽

Antibody Tests ◽

Spike Proteins

AbstractThe objective of this study was to evaluate the performance of a lateral flow antibody test for COVID-19, approved for use in India. Although many point-of-care antibody tests are available globally, they have been subjected to limited clinical validation. This has led to suboptimal outcomes in the field, where antibody tests play a significant role in tracking the immunity of individuals and communities. In this study an antibody test, ImmunoQuick that recognizes antibodies to the Nucleocapsid and Spike proteins of SARS CoV-2 was tested in 100 symptomatic patients with a positive or negative diagnosis of COVID-19, based on RT-PCR results. The overall sensitivity of the test was found to be 86.1% (95% CI: 76.4% to 92.8%) and specificity 100% (95% confidence interval: 73.5% to 100%). The sensitivity reached a peak of 95.7% with samples taken 17 days after the onset of symptoms. Overall, the sensitivity and specificity of the test are sufficient for assessing seroprevalence.

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Diagnostic accuracy and utility of SARS-CoV-2 antigen lateral flow assays in medical admissions with possible COVID-19

10.1101/2021.01.27.21250428 ◽

2021 ◽

Author(s):

Hamish Houston ◽

Ankur Gupta-Wright ◽

Edward Toke-Bjolgerud ◽

James Biggin-Lamming ◽

Laurence John

Keyword(s):

Diagnostic Accuracy ◽

Hospital Admissions ◽

Case Definition ◽

Acute Hospital ◽

Lateral Flow ◽

Rt Pcr ◽

Lateral Flow Assays ◽

Qualitative Test ◽

The Uk

AbstractWe evaluated diagnostic accuracy of the Innova SARS-CoV-2 Antigen Rapid Qualitative Test compared to SARS-CoV-2 RT-PCR from nasopharyngeal swabs in adult admissions who met the COVID-19 case definition at a busy acute hospital in the UK. We found the Innova SARS-CoV-2 Antigen Rapid Qualitative Test had a good specificity in patients with symptoms of COVID-19 presenting to hospital. The Innova LFA can be used to rapidly identify COVID-19 cases amongst hospital admissions meeting the COVID-19 case definition, allowing patients to be allocated to COVID-19 cohort areas.

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Clinical Evaluation of a COVID-19 Antibody Lateral Flow Assay using Point of Care Samples

10.1101/2020.12.02.20242750 ◽

2020 ◽

Author(s):

Won Lee ◽

Steven Straube ◽

Ryan Sincic ◽

Jeanne A. Noble ◽

Juan Carlos Montoy ◽

...

Keyword(s):

Predictive Value ◽

Point Of Care ◽

Acute Infection ◽

High Specificity ◽

Lateral Flow ◽

Lateral Flow Immunoassay ◽

Onset Date ◽

Rt Pcr ◽

Serum Samples ◽

Antibody Positivity

ABSTRACTIntroductionThe ongoing SARS-CoV-2 pandemic has spurred the development of numerous point of care (PoC) immunoassays. Assessments of performance of available kits are necessary to determine their clinical utility. Previous studies have mostly performed these assessments in a laboratory setting, which raises concerns of translating findings for PoC use. The aim of this study was to assess the performance of a lateral flow immunoassay for the detection of SARS-CoV-2 antibodies using samples collected at PoC.MethodOne lateral flow immunoassay (Humasis® COVID-19 IgG/IgM) was tested. In total, 50 PCR RT-PCR positive and 52 RT-PCR negative samples were collected at PoC. Fifty serum specimens from Dec 2018 to Feb 2019 were used as controls for specificity. Serum samples collected between Dec 2019 to Feb 2020 were used as additional comparators. Clinical data including symptom onset date was collected from patient history and the medical record.ResultsThe overall sensitivity for the kit was 74% (95% CI: 59.7% -85.4%). The sensitivity for IgM and IgG detection >14 days after date of onset was 88% (95% CI: 68.8% -97.5%) and 84% (95% CI: 63.9% – 95.5%), with a negative predictive value (NPV) of 94% for IgM (95% CI: 83.5% - 98.8%) and 93% for IgG (95% CI: 81.8% - 97.9%). The overall specificity was 94% (95% CI: 83.5% - 98.8%). The Immunoglobulin specific specificity was 94% for IgM (95% CI: 83.5% - 98.8%) and 98% for IgG (95% CI: 89.4% - 100.0%), with a positive predictive value (PPV) of 88% for IgM (95% CI: 68.8% - 97.5%) and 95% for IgG (95% CI: 77.2% - 99.9%) respectively for samples collected from patients >14 days after date of onset. Specimen collected during early phase of COVID-19 pandemic (Dec 2019 to Feb 2020) showed 11.8% antibody positivity, and 11.3% of PCR-negative patients demonstrated antibody positivity.DiscussionHumasis® COVID-19 IgG/IgM LFA demonstrates greater than 90% PPV and NPV for samples collected 14 days after the onset of symptoms using samples collected at PoC. While not practical for the diagnosis of acute infection, the use of the lateral flow assays with high specificity may have utility for determining seroprevalence or seroconversion in longitudinal studies.

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Diagnostic accuracy of two commercial SARS-CoV-2 antigen-detecting rapid tests at the point of care in community-based testing centers

PLoS ONE ◽

10.1371/journal.pone.0248921 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0248921

Author(s):

Alice Berger ◽

Marie Therese Ngo Nsoga ◽

Francisco Javier Perez-Rodriguez ◽

Yasmine Abi Aad ◽

Pascale Sattonnet-Roche ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Point Of Care ◽

Rapid Test ◽

Diagnostic Value ◽

Ease Of Use ◽

Lower Sensitivity ◽

Rt Pcr ◽

Test Device ◽

Community Based ◽

Rapid Tests

Objectives Determine the diagnostic accuracy of two antigen-detecting rapid diagnostic tests (Ag-RDT) for SARS-CoV-2 at the point of care and define individuals’ characteristics providing best performance. Methods We performed a prospective, single-center, point of care validation of two Ag-RDT in comparison to RT-PCR on nasopharyngeal swabs. Results Between October 9th and 23rd, 2020, 1064 participants were enrolled. The PanbioTM Covid-19 Ag Rapid Test device (Abbott) was validated in 535 participants, with 106 positive Ag-RDT results out of 124 positive RT-PCR individuals, yielding a sensitivity of 85.5% (95% CI: 78.0–91.2). Specificity was 100.0% (95% CI: 99.1–100) in 411 RT-PCR negative individuals. The Standard Q Ag-RDT (SD Biosensor, Roche) was validated in 529 participants, with 170 positive Ag-RDT results out of 191 positive RT-PCR individuals, yielding a sensitivity of 89.0% (95%CI: 83.7–93.1). One false positive result was obtained in 338 RT-PCR negative individuals, yielding a specificity of 99.7% (95%CI: 98.4–100). For individuals presenting with fever 1–5 days post symptom onset, combined Ag-RDT sensitivity was above 95%. Lower sensitivity of 88.2% was seen on the same day of symptom development (day 0). Conclusions We provide an independent validation of two widely available commercial Ag-RDTs, both meeting WHO criteria of ≥80% sensitivity and ≥97% specificity. Although less sensitive than RT-PCR, these assays could be beneficial due to their rapid results, ease of use, and independence from existing laboratory structures. Testing criteria focusing on patients with typical symptoms in their early symptomatic period onset could further increase diagnostic value.

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