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

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

Diagnosis ◽

10.1515/dx-2020-0154 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Gian Luca Salvagno ◽

Gianluca Gianfilippi ◽

Damiano Bragantini ◽

Brandon M. Henry ◽

Giuseppe Lippi

Keyword(s):

Clinical Assessment ◽

Clinical Performance ◽

Point Of Care ◽

High Viral Load ◽

Rapid Screening ◽

Clinical Samples ◽

Molecular Testing ◽

Antigen Test ◽

Community Screening ◽

Final Study

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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Performance Evaluation and Multicenter Consistency Study of Smartphone-based Hipee S2 Point-of-care Testing Urine Dipstick Analyser: Evaluation Study (Preprint)

10.2196/preprints.30957 ◽

2021 ◽

Author(s):

Qiang Zhang ◽

Guoqing Wang ◽

Xiaolong Zong ◽

Jinghua Sun

Keyword(s):

Health Management ◽

Clinical Performance ◽

Point Of Care ◽

Method Comparison ◽

Evaluation Study ◽

Analytical Performance ◽

Point Of Care Testing ◽

Urine Dipstick ◽

Quantitative Results ◽

Carry Over

BACKGROUND With advances in mobile technology, smartphone-based point-of-care testing (POCT) urinalysis hold great potential for disease screening and health management for clinicians and individual users. The POCT devices need to have good analytical and clinical performance, but data are lacking. OBJECTIVE The purpose of this study is to evaluate the analytical performance of smartphone-based Hipee S2 POCT urine dipstick analyser. METHODS A total of 1,603 urine samples from three hospitals were collected. Precision, drift, carry-over, interference, and method comparison of Hipee S2 were evaluated. RESULTS The precision for each parameter, assessed by control materials, was acceptable. No sample carry-over or drift was observed. Ascorbate solution with 1 g/L had an inhibitory effect for the haemoglobin test. Agreement for specific gravity (SG) varied between moderate to substantial, for pondus hydrogenii (pH) was moderate, and for other parameters varied between substantial to excellent, on comparing the results obtained by Hipee S2 with those measured by laboratory reference analysers. The semi-quantitative results of microalbumin and creatinine were highly correlated with the quantitative results. CONCLUSIONS Hipee S2 POCT urine analyser showed acceptable analytical performance as a semi-quantitative method. It serves as a convenient alternate device for clinicians and individual users for urinalysis and health management.

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Point-of-Care Test for Detection of Urogenital Chlamydia in Women Shows Low Sensitivity. A Performance Evaluation Study in Two Clinics in Suriname

PLoS ONE ◽

10.1371/journal.pone.0032122 ◽

2012 ◽

Vol 7 (2) ◽

pp. e32122 ◽

Cited By ~ 40

Author(s):

Jannie J. van der Helm ◽

Leslie O. A. Sabajo ◽

Antoon W. Grunberg ◽

Servaas A. Morré ◽

Arjen G. C. L. Speksnijder ◽

...

Keyword(s):

Performance Evaluation ◽

Point Of Care ◽

Evaluation Study ◽

Point Of Care Test ◽

Low Sensitivity ◽

A Performance

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New point of care Chlamydia Rapid Test—bridging the gap between diagnosis and treatment: performance evaluation study

BMJ ◽

10.1136/bmj.39402.463854.ae ◽

2007 ◽

Vol 335 (7631) ◽

pp. 1190-1194 ◽

Cited By ~ 59

Author(s):

Lourdes Mahilum-Tapay ◽

Vivian Laitila ◽

James J Wawrzyniak ◽

Helen H Lee ◽

Sarah Alexander ◽

...

Keyword(s):

Performance Evaluation ◽

Point Of Care ◽

Rapid Test ◽

Evaluation Study ◽

Diagnosis And Treatment ◽

Treatment Performance

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Feasibility and Effectiveness Assessment of SARS-CoV-2 Antigenic Tests in Mass Screening of a Pediatric Population and Correlation with the Kinetics of Viral Loads

Viruses ◽

10.3390/v13102071 ◽

2021 ◽

Vol 13 (10) ◽

pp. 2071

Author(s):

Marcello Lanari ◽

Giovanni Battista Biserni ◽

Matteo Pavoni ◽

Eva Caterina Borgatti ◽

Marta Leone ◽

...

Keyword(s):

Viral Load ◽

Mass Screening ◽

Point Of Care ◽

Pediatric Population ◽

Late Phase ◽

High Viral Load ◽

Pediatric Emergency ◽

Nucleic Acid Amplification ◽

Baseline Sensitivity ◽

Viral Loads

The gold standard for diagnosis of SARS-CoV-2 infection has been nucleic acid amplification tests (NAAT). However, rapid antigen detection kits (Ag-RDTs), may offer advantages over NAAT in mass screening, generating results in minutes, both as laboratory-based test or point-of-care (POC) use for clinicians, at a lower cost. We assessed two different POC Ag-RDTs in mass screening versus NAAT for SARS-CoV-2 in a cohort of pediatric patients admitted to the Pediatric Emergency Unit of IRCCS—Polyclinic of Sant’Orsola, Bologna (from November 2020 to April 2021). All patients were screened with nasopharyngeal swabs for the detection of SARS-CoV-2-RNA and for antigen tests. Results were obtained from 1146 patients. The COVID-19 Ag FIA kit showed a baseline sensitivity of 53.8% (CI 35.4–71.4%), baseline specificity 99.7% (CI 98.4–100%) and overall accuracy of 80% (95% CI 0.68–0.91); the AFIAS COVID-19 Ag kit, baseline sensitivity of 86.4% (CI 75.0–93.9%), baseline specificity 98.3% (CI 97.1–99.1%) and overall accuracy of 95.3% (95% CI 0.92–0.99). In both tests, some samples showed very low viral load and negative Ag-RDT. This disagreement may reflect the positive inability of Ag-RDTs of detecting antigen in late phase of infection. Among all cases with positive molecular test and negative antigen test, none showed viral loads > 106 copies/mL. Finally, we found one false Ag-RDTs negative result (low cycle thresholds; 9 × 105 copies/mL). Our results suggest that both Ag-RDTs showed good performances in detection of high viral load samples, making it a feasible and effective tool for mass screening in actively infected children.

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Performance evaluation of Xpert HBV viral load (VL) assay: Point-of-care molecular test to strengthen and decentralize management of chronic hepatitis B (CHB) infection

Journal of Virological Methods ◽

10.1016/j.jviromet.2021.114063 ◽

2021 ◽

Vol 290 ◽

pp. 114063 ◽

Cited By ~ 1

Author(s):

Ekta Gupta ◽

Arvind Khodare ◽

Nitiksha Rani ◽

Gaurav Singh ◽

Kavita Aggarwal ◽

...

Keyword(s):

Chronic Hepatitis ◽

Performance Evaluation ◽

Viral Load ◽

Hepatitis B ◽

Chronic Hepatitis B ◽

Point Of Care ◽

Molecular Test

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A novel RT-LAMP workflow for rapid salivary diagnostics of COVID-19 and effects of age, gender and time from symptom onset

10.1101/2021.06.07.21258288 ◽

2021 ◽

Author(s):

Gerson Shigeru Kobayashi ◽

Luciano Abreu Brito ◽

Danielle De Paula Moreira ◽

Angela May Suzuki ◽

Gabriella Shih Ping Hsia ◽

...

Keyword(s):

Viral Load ◽

Symptom Onset ◽

Clinical Performance ◽

Point Of Care ◽

Rapid Diagnostics ◽

Rt Pcr ◽

Point Of Care Testing ◽

Viral Loads ◽

Peak Viral Load ◽

Salivary Diagnostics

Objectives: Rapid diagnostics is pivotal to curb SARS-CoV-2 transmission, and saliva has emerged as a practical alternative to naso/oropharyngeal (NOP) specimens. We aimed to develop a direct RT-LAMP workflow for viral detection in saliva, and to provide more information regarding its potential in COVID-19 diagnostics. Methods: Clinical and contrived specimens were used to screen/optimize formulations and sample processing protocols. Salivary viral load was determined in symptomatic patients to evaluate clinical performance (n = 90) and to characterize saliva based on age, gender and time from onset of symptoms (n = 49). Results: The devised workflow achieved 93.2% sensitivity, 97% specificity, and 0.895 Kappa for salivas containing >102 copies/μL. Further analyses in saliva showed peak viral load in the first days of symptoms and lower viral loads in females, particularly among young individuals (<38 years). NOP RT-PCR data did not yield relevant associations. Conclusions: This novel saliva RT-LAMP workflow can be applied to point-of-care testing. This work reinforces that saliva better correlates with transmission dynamics than NOP specimens, and reveals gender differences that may reflect higher transmission by males. To maximize detection, testing should be done immediately after symptom onset, especially in females.

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SARS-CoV-2 infectivity correlates with high viral loads and detection of viral antigen and is terminated by seroconversion

The Journal of Infectious Diseases ◽

10.1093/infdis/jiab415 ◽

2021 ◽

Author(s):

Felix Buder ◽

Markus Bauswein ◽

Clara L Magnus ◽

Franz Audebert ◽

Henriette Lang ◽

...

Keyword(s):

Viral Load ◽

Symptom Onset ◽

Viral Antigen ◽

Virus Isolation ◽

Point Of Care ◽

High Viral Load ◽

University Hospital ◽

Public Health Perspective ◽

Viral Loads ◽

Restrictive Measures

Abstract Background From a public health perspective, effective containment strategies for SARS-CoV-2 should be balanced with individual liberties. Methods We collected 79 respiratory samples from 59 patients monitored in an outpatient center or in the intensive care unit of the University Hospital Regensburg. We analyzed viral load by quantitative real-time PCR, viral antigen by point-of-care assay, time since onset of symptoms and presence of SARS-CoV-2 IgG antibodies in the context of virus isolation from respiratory specimen. Results The odds ratio for virus isolation increased 1.9-fold for each log10 level of SARS-CoV-2 RNA and 7.4-fold with detection of viral antigen, while it decreased 6.3-fold beyond 10 days of symptoms and 20.0-fold with presence of SARS-CoV-2 antibodies. The latter was confirmed for B.1.1.7 strains. The positive predictive value for virus isolation was 60.0% for viral loads above 10 7 RNA copies/mL and 50.0% for the presence of viral antigen. Symptom onset before 10 days and seroconversion predicted lack of infectivity with 93.8% and 96.0%. Conclusions Our data support quarantining patients with high viral load and detection of viral antigen, and lifting restrictive measures with increasing time to symptom onset and seroconversion. Delay of antibody formation may prolong infectivity.

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