Performance Evaluation of the STANDARDTM Q COVID-19 and PanbioTM COVID-19 Antigen Tests in Detecting SARS-CoV-2 during High Transmission Period in Mozambique

The diagnostic performance evaluation of Panbio and STANDARD Q coronavirus disease 2019 antigen tests against real-time polymerase chain reaction in southern Ethiopia

The coronavirus disease 2019 (COVID-19) pandemic has created a public health crisis. This study aimed to evaluate the diagnostic performance of the Panbio and STANDARD Q COVID-19 antigen rapid diagnostic tests (RDTs) against the real-time polymerase chain reaction (RT-PCR) at one of the largest hospitals in southern Ethiopia. Nasopharyngeal samples, which were collected during the pandemic from individuals suspected of COVID-19 and stored at - 70 °C, were analyzed in June and July 2022. The performance of the Panbio COVID-19 antigen tests was evaluated in 200 randomly selected nasopharyngeal samples (100 positives and 100 negatives for severe acute respiratory syndrome 2 by RT-PCR). The STANDARD Q test was evaluated using 100 positive and 50 negative samples. The respective sensitivity, specificity, positive predictive value and negative predictive values were 88%, 99%, 98.9% and 89.2% for the Panbio test and 91%, 98%, 98.9% and 84.5%, for the STANDARD Q test. The kappa values were 0.87 for the Panbio and 0.86 for the STANDARD Q test. Based on the findings presented here, the RDTs could be utilized as an alternative to conventional RT-PCR when it is challenging to diagnose COVID-19 owing to a lack of time, skilled lab personnel, or suitable equipment or electricity.

Development and Clinical Performance of InteliSwab® COVID-19 Rapid Test: Evaluation of Antigen Test for the Diagnosis of SARS-CoV-2 and Analytical Sensitivity to Detect Variants of Concern Including Omicron and Subvariants

BACKGROUND AND OBJECTIVES

Timely detection of SARS-CoV-2 infection with subsequent contact tracing and rapid isolation are considered critical to containing the pandemic, which continues with the emergence of new variants. Hence, there is an ongoing need for reliable point-of-care antigen rapid diagnostic tests (Ag-RDT). This report describes the development, evaluation, and analytical sensitivity of the diagnostic performance of the InteliSwab® COVID-19 Rapid Test. Methods: Samples from 165 symptomatic subjects were tested with InteliSwab® and the results were compared to RT-PCR to determine the antigen test performance. The analytical sensitivity of InteliSwab® for the detection of different variants was assessed by limit of detection (LOD) determination using recombinant nucleocapsid proteins (NPs) and testing with virus isolates. Western immunoblot independently confirmed that each monoclonal Ab is capable of binding to all variants tested thus far.

RESULTS

The overall positivity rate by RT-PCR was 37% for the 165 symptomatic subjects. Based on RT-PCR results as the reference standard, InteliSwab® showed clinical sensitivity and specificity of 85.2% (95% CI, 74.3-92.0%) and 98.1% (95% CI, 93.3-99.7%), respectively. The overall agreement was 93.3% (Kappa index value 0.85; 95% CI, 0.77-0.74) between RT-PCR and InteliSwab® test results. Furthermore, the evaluation of analytical sensitivity for different SARS-CoV-2 variants by InteliSwab® was comparable in the detection of all the variants tested, including Omicron subvariants, BA.4, BA.5, and BQ.1.

CONCLUSIONS

Due to the surge of infections caused by different variants from time to time, there is a critical need to evaluate the sensitivity of rapid antigen-detecting tests for new variants. The study findings showed the robust diagnostic performance of InteliSwab® and analytical sensitivity in detecting different SARS-CoV-2 variants, including the Omicron subvariants. With the integrated swab and excellent sensitivity and variant detection, this test has high potential as a point-of-care Ag-RDT in various settings when molecular assays are in limited supply and rapid diagnosis of SARS-CoV-2 is necessary.

Diagnostic evaluation of Panbio™ antigen rapid diagnostic test for SARS-CoV-2: A systematic review and meta-analysis

INTRODUCTION

The reverse transcriptase polymerase chain reaction (RT-PCR) is the reference diagnostic method for the confirmation of SARS-CoV-2 infected cases. However, various antigen rapid diagnostic tests (Ag-RDTs) have been developed. The purpose of this meta-analysis study was to assess the diagnostic performance of Panbio™ Ag-RDT (Abbott Point of Care) in identifying the SARS-CoV-2 virus.

METHODS

We systematically searched eight databases from March 2020 until March 2023 to look for potentially eligible articles. Diagnostic meta-analysis of Panbio™ Ag-RDT used diverse evaluation indicators, including sensitivity, specificity, Diagnostic Odds Ratio (DOR), and the area under the curve (AUC) value.

RESULTS

Of the 794 articles identified, 49 studies met the inclusion criteria. The pooled estimates of Panbio™ Ag-RDT for the diagnosis of SARS-CoV-2 were 0,65 (95% CI: 0,64-0,66), 0,99 (95% CI: 0,99-1,00), 578,03 (95% CI: 333,37-1002,26) for sensitivity, specificity, and DOR, respectively. Moreover, the summary receiver operating characteristic (SROC) curve revealed an AUC value of 0,942 (95% CI: 0,941-0,943), suggesting an outstanding diagnostic accuracy. Subgroup and meta-regression analyses showed that continent, study period, age, study population and cycle threshold (Ct) values constituted a source of heterogeneity. Furthermore, we demonstrated proof of publication bias for DOR values analyzed using Deek's test (p = 0,001) and funnel plot.

CONCLUSION

Panbio™ Ag-RDT presented an outstanding diagnostic accuracy in the detection of the SARS-CoV-2 virus in both adults and children with or without symptoms.

SARS-CoV-2 Testing Strategies in the Diagnosis and Management of COVID-19 Patients in Low-Income Countries: A Scoping Review

The accuracy of diagnostic laboratory tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can impact downstream clinical procedures in managing and controlling the outbreak of coronavirus disease 2019 (COVID-19). To assess the effectiveness of laboratory tools for managing COVID-19 patients in low-income countries (LICs), we systematically searched the PubMed, Embase, Scopus and CINHAL databases for reports published between January 2020 and June 2022. We found that 22 of 1303 articles reported the performance of various SARS-CoV-2 detection tools across 10 LICs. These tools were (1) real-time reverse transcriptase polymerase chain reaction (RT-PCR); (2) reverse transcription loop-mediated isothermal amplification (RT-LAMP); (3) rapid diagnostic tests (RDTs); (4) enzyme-linked immunosorbent assay (ELISA); and (5) dot-blot immunoassay. The detection of COVID-19 is largely divided into two main streams-direct virus (antigen) detection and serology (immunoglobulin)-based detection. Point-of-care testing using antigen-based RDTs is preferred in LICs because of cost effectiveness and simplicity in the test procedures. The nucleic acid amplification technology (RT-PCR and RT-LAMP) has the highest diagnostic performance among the available tests, but it is not broadly used in this context due to costs and shortage of facilities/trained staff. The serology-based test method is affected by antibody interferences and varying amounts of SARS-CoV-2 immunoglobulins expressed at different stages of disease onset. We further discuss the effectiveness and shortcomings of each of these tools in the diagnosis and management of COVID-19. Using the LICs as the study model, our findings highlight ways to improve the quality and turnaround time of COVID-19 testing in resource-constrained settings, notably through local/international collaborative efforts to refine the molecular-based or immunoassay-based testing technologies.

Evaluation of the diagnostic performance of PanbioTM Abbott SARS-CoV-2 rapid antigen test for the detection of COVID-19 from suspects attending ALERT center

BACKGROUND

The emergence and rapid spread of coronavirus disease 2019 (COVID-19), a potentially lethal disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is causing public health issues around the world. In resource-constrained nations, rapid Abbott SARS-CoV-2 antigen test kits are critical for addressing diagnostic gaps in health institutions and community screening. However, there is no evidence or proof of diagnostic performance in Ethiopia. The aim of this study was to compare the performance of PanbioTM Abbott SARS-CoV-2antigen rapid test kit to the gold standard, RT-PCR, in COVID-19 patients with clinical symptoms suggestive of COVID-19.

METHOD

A prospective, cross-sectional study was conducted between November 2021 and April 2022, on 120 suspected patients recruited from outpatient, emergency, and intensive care units in one of the tertiary hospitals in Ethiopia. Nasopharyngeal swabs were collected from suspected cases and were tested using the Abbott SARS-CoV-2 kit, a rapid diagnostic test (RDT) and compared to the reference standard RT-PCR.

RESULT

The sensitivity and specificity of the RDT were 74.2% and 100%, respectively. A total of 62 samples (51.6%) were RT-PCR positive. Of these, 46 were Ag-RDT positive. Sensitivity among symptomatic patients was 79.4% (95% CI 68.3-90). The Abbot RDT and RT-PCR had a Kappa value of agreement of 0.735 (p < 0.001). These values were acceptable when compared to the WHO's suggested thresholds.

CONCLUSION

The finding from this study support the use of the Abbot RDT as a diagnostic tool in COVID-19 suspects, mainly in those with higher viral loads.

Clinical Performance of Self-Collected Nasal Swabs and Antigen Rapid Tests for SARS-CoV-2 Detection in Resource-Poor Settings

Background: In resource-poor countries, antigen-based rapid tests (Ag-RDTs) performed at primary healthcare and community settings improved access to SARS-CoV-2 diagnostics. However, the technical skills and biosafety requirements inherent to nasopharyngeal and oropharyngeal (OP) specimens limit the scale-up of SARS-CoV-2 testing. The collection of nasal-swabs is programmatically viable, but its performance has not been evaluated in resource-poor settings. Methods: We first evaluated the performance of SteriPack self-collected nasal swabs for the detection of SARS-CoV-2 by real-time PCR in 1498 consecutively enrolled patients with suspected infection. Next, we evaluated the clinical performance of three nasal swab-based Ag-RDTs against real-time PCR on OP specimens. Results: The sensitivity of nasal swabs was 80.6% [95% CI: 75.3−85.2%] compared to OP specimens. There was a good correlation (r = 0.58; p < 0.0001) between Ct values of 213 positive cases obtained using nasal and OP swabs. Our findings show sensitivities of 79.7% [95% CI: 73.3−85.1%] for Panbio COVID-19 Ag-RDT, 59.6% [95% CI: 55.2−63.8%] for COVIOS Ag-RDT, and 78.0% [95% CI: 73.5−82.0%] for the LumiraDx SARS-CoV-2 Ag-RDT. Conclusions: In our setting, the COVIOS Ag-RDT did not meet WHO requirements. Nasal swab-based Ag-RDTs for SARS-CoV-2 detection constitute a viable and accurate diagnostic option in resource-poor settings.