scholarly journals Diagnostic accuracy of two commercially available rapid assays for detection of IgG and IgM antibodies to SARS-CoV-2 compared to ELISA in a low-prevalence population

2020 ◽  
Author(s):  
Klaus Hackner ◽  
Peter Errhalt ◽  
Martin Willheim ◽  
Maria-Anna Grasl ◽  
Jasmina Lagumdzija ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Close Contact ◽  
Point Of Care ◽  
Rapid Test ◽  
Screen Test ◽  
Elisa Test ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rapid Assays ◽  
Low Prevalence

Abstract Background: New commercially available point-of-care (POC) immunodiagnostic tests are appearing, which may yield rapid results for anti-SARS-CoV-2 antibodies. The aim of this study was to evaluate the diagnostic accuracy of rapid antibody detection tests compared to a validated laboratory-based enzyme-linked immunosorbent assay (ELISA) and to investigate infections amongst healthcare workers (HCWs) after unprotected close contact to COVID-19 patients. Methods: Blood serum and whole blood of 130 participants were tested with NADAL® COVID-19 IgG/IgM Rapid Test and mö-screen 2019-NCOV Corona Virus Test against a validated ELISA test. Infection status was evaluated using real-time polymerase-chain-reaction.Results: Acute COVID-19 infection was detected in 2.4% of exposed HCWs. Antibody tests showed an overall frequency of IgG and IgM in 5.3%, with 1.6% asymptomatic infections. The NADAL® test showed a sensitivity (IgM/ IgG) of 100% (100%/ 100%), a specificity (IgM/ IgG) of 98.8% (97.6%/ 100 %), a PPV of 76.9% (57.1%/ 100%), an NPV of 100% (100%/ 100%), and a diagnostic accuracy of 98.8% (97.7%/ 100%). The mö-screen test had a sensitivity (IgM/IgG) of 90.9% (80%/ 100%), a specificity (IgM/IgG) of 98.8% (97.6%/ 100%), a PPV of 76.9% (57.1%/ 100%), an NPV of 99.6% (99.2%/ 100%), and a diagnostic accuracy of 98.5% (96.9%/ 100%). Conclusions: The frequency of COVID-19 infections in HCWs after unprotected close contact is higher than in the general population of a low-prevalence country. Both POC tests were useful for detecting IgG, but did not perform well for IgM, mainly due to false positive results.

scholarly journals Validation of a Novel Commercial ELISA Test for the Detection of Antibodies against Coxiella burnetii

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1075
Author(s):  
Salvatore Ledda ◽  
Cinzia Santucciu ◽  
Valentina Chisu ◽  
Giovanna Masala
Keyword(s):  
Diagnostic Accuracy ◽  
Phase Ii ◽  
Coxiella Burnetii ◽  
Q Fever ◽  
Animal Health ◽  
Elisa Test ◽  
Clinical Diagnostics ◽  
Complex Life Cycle ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specificity And Sensitivity

Q fever is a zoonosis caused by Coxiella burnetii, a Gram-negative pathogen with a complex life cycle and a high impact on public and animal health all over the world. The symptoms are indistinguishable from those belonging to other diseases, and the disease could be symptomless. For these reasons, reliable laboratory tests are essential for an accurate diagnosis. The aim of this study was to validate a novel enzyme-linked immunosorbent assay (ELISA) test, named the Chorus Q Fever Phase II IgG and IgM Kit (DIESSE, Diagnostica Senese S.p.A), which is performed by an instrument named Chorus, a new device in medical diagnostics. This diagnostic test is employed for the detection of antibodies against C. burnetii Phase II antigens in acute disease. Our validation protocol was performed according to the Italian Accreditation Body (ACCREDIA) (Regulation UNI CEI EN ISO/IEC 17025:2018 and 17043:2010), OIE (World Organization for Animal Health), and Statement for Reporting Studies of Diagnostic Accuracy (STARD). Operator performance was evaluated along with the analytical specificity and sensitivity (ASp and ASe) and diagnostic accuracy of the kit, with parameters such as diagnostic specificity and sensitivity (DSp and DSe) and positive and negative predictive values (PPV and NPV), in addition to the repeatability. According to the evaluated parameters, the diagnostic ELISA test was shown to be suitable for validation and commercialization as a screening method in human sera and a valid support for clinical diagnostics.

scholarly journals Rapid point-of-care anti-infliximab antibodies detection in clinical practice: comparison with ELISA and potential for improving therapeutic drug monitoring in IBD patients

2021 ◽  
Vol 14 ◽  
pp. 175628482199990
Author(s):  
Sonia Facchin ◽  
Andrea Buda ◽  
Romilda Cardin ◽  
Nada Agbariah ◽  
Fabiana Zingone ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Point Of Care ◽  
Drug Clearance ◽  
Elisa Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Therapeutic Drug ◽  
Drug Concentrations ◽  
Inflammatory Bowel

Anti-drug antibodies can interfere with the activity of anti-tumor necrosis factor (TNF) agents by increasing drug clearance via direct neutralization. The presence of anti-drug antibodies is clinically relevant when trough drug concentrations are undetectable or sub-therapeutic. However, traditional immunoassay is not easily and rapidly accessible, making the translation of the results into treatment adjustment difficult. The availability of a point-of-care (POC) test for therapeutic drug monitoring (TDM) might represent an important step forward for improving the management of inflammatory bowel disease (IBD) patients in clinical practice. In this pilot study, we compared the results obtained with POC tests with those obtained by enzyme-linked immunosorbent assay (ELISA) in a group of IBD patients treated with Infliximab (IFX). We showed that POC test can reliably detect presence of antibody-to-IFX with 100% of specificity and 76% sensitivity, in strong agreement with the ELISA test ( k-coefficient = 0.84).

scholarly journals A Rapid Immunochromatography Test Based on Hcp1 Is a Potential Point-of-Care Test for Serological Diagnosis of Melioidosis

2018 ◽  
Vol 56 (8) ◽  
Author(s):  
Phornpun Phokrai ◽  
Wisansanee Karoonboonyanan ◽  
Nida Thanapattarapairoj ◽  
Chidchanok Promkong ◽  
Adul Dulsuk ◽  
...  
Keyword(s):  
Point Of Care ◽  
Clinical Manifestations ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Target Antigen ◽  
Northeast Thailand ◽  
Serum Samples ◽  
Serological Method ◽  
Healthy Donors ◽  
Wide Range

ABSTRACTMelioidosis is a fatal infectious disease caused by the environmental bacteriumBurkholderia pseudomallei. It is highly endemic in Asia and northern Australia but neglected in many other tropical countries. Melioidosis patients have a wide range of clinical manifestations, and definitive diagnosis requires bacterial culture, which can be time-consuming. A reliable rapid serological tool is greatly needed for disease surveillance and diagnosis. We previously demonstrated by enzyme-linked immunosorbent assay (ELISA) that a hemolysin-coregulated protein (Hcp1) is a promising target for serodiagnosis of melioidosis. In this study, we developed a rapid immunochromatography test (ICT) using Hcp1 as the target antigen (Hcp1-ICT). We evaluated this test for specific antibody detection using serum samples obtained from 4 groups of human subjects, including the following: (i) 487 culture-confirmed melioidosis patients from four hospitals in northeast Thailand; (ii) 202 healthy donors from northeast Thailand; (iii) 90 U.S. healthy donors; and (iv) 207 patients infected with other organisms. Compared to culture results as a gold standard, the sensitivity of ICT for all hospitals was 88.3%. The specificities for Thai donors and U.S. donors were 86.1% and 100%, respectively, and the specificity for other infections was 91.8%. The results of the Hcp1-ICT demonstrated 92.4% agreement with the Hcp1-ELISA results with a kappa value of 0.829, indicating that the method is much improved compared with the current serological method, the indirect hemagglutination assay (IHA) (69.5% sensitivity and 67.6% specificity for Thais). The Hcp1-ICT represents a potential point-of-care (POC) test and may be used to replace the IHA for screening of melioidosis in hospitals as well as in resource-limited areas.

scholarly journals Comparative Analysis of the Analytical Sensitivity of ELISA Test System DIA®-SARS-CoV-2-Ag-R with Rapid Tests for Viral Antigen SARS-CoV-2 Detection

2021 ◽  
Vol 83 (3) ◽  
pp. 66-71
Author(s):  
А.Y. Horlov ◽  
◽  
V.H. Serdiuk ◽  
О.K. Kiselova ◽  
A.O. Shevchuk ◽  
...  
Keyword(s):  
Viral Antigen ◽  
False Negative ◽  
Medical Science ◽  
Rapid Test ◽  
Test System ◽  
Elisa Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Analytical Sensitivity ◽  
Rapid Tests ◽  
Positive Results

A novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease (COVID)-19, that emerged as a major pandemic. SARS-CoV-2 was identified as a betacoronavirus. Nucleocapsid protein (NP) is evolutionary high protein homologies and solid structure protein for SARS-CoV-2 detection as opposed to other proteins, that aren`t reliable as a single viral antigen during diagnostics methods. The viral RNA can be detected from nasal and pharyngeal swabs and bronchoalveolar lavage samples by PCR assay. However, the wrong collection of samples can lead to false-negative diagnosis and have dangerous consequences at this stage of pandemic. One of efficient and accurate methodological approaches for the screening of pathogens are serological assays. Aim. Evaluation and comparison of the sensitivity of invented DIA®-SARS-CoV-2-Ag-R enzyme-linked immunosorbent assay (ELISA)-based test system and commercial rapid tests, which detect the viral antigen of SARS-CoV-2. Methods. We carried out a comparison of DIA®-SARS-CoV-2-Ag-R and existed commercial test systems, which are used to detect the antigen of SARS-CoV-2 virus. Rapid tests are intended for nasopharyngeal swabs, but we proposed a protein of our own manufacture – recombinant NP as a calibrator. The detection limit was calibrated by standard CFAR #100982 NIBSC, UK. We had determined levels of NP (1400, 900, 750, 640 and 280 pg/mL) that we used as a sample for the rapid tests. The COVID-19 Ag Rapid Tests were performed according to the manufactures instructions at room temperature. Results. DIA®-SARS-CoV-2-Ag-R detected 10 pg/mL of in-house standard of recombinant SARS-CoV-2 NP. The positive results were observed using 1400, 900, 750 pg/mL, while 640 and 280 pg/mL samples were performed as negative in ABBOTT-PanBio test. The rapid tests manufactured by МBU, BIOTIME, Core Technology, SD BIOSENSOR and Turklab showed positive results only in 1400 pg/mL concentration. NP of lower levels was detected as a negative sample. The LEPU MEDICAL test was evaluated as positive sample using 900 pg/mL. The rapid test manufactured by Green Cross Medical Science Corp. showed negative results for all levels of NP. It can mean that the sensitivity of test is lower and demands higher level of antigen to detect the presence of SARS-CoV-2. Conclusions. The study presented an excellent analytical sensitivity of DIA®-SARS-CoV-2-Ag-R against commercial Antigen rapid tests. Thus, invented ELISA test system can be recommended for widespread usage for detection and confirmation of acute stage of SARS-CoV-2 infection.

scholarly journals Performance of SARS-CoV-2 Serology tests: Are they good enough?

2020 ◽  
Author(s):  
Isabelle Piec ◽  
Emma English ◽  
M Annette Thomas ◽  
Samir Dervisevic ◽  
William D Fraser ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Respiratory Infections ◽  
Point Of Care ◽  
False Negative ◽  
Rapid Test ◽  
Diagnostic Sensitivity ◽  
Medical Community ◽  
Antibody Detection ◽  
Serological Tests ◽  
Negative Results

AbstractBackgroundIn the emergency of the SARS-CoV-2 pandemic, great efforts were made to quickly provide serology testing to the medical community however, these methods have been introduced into clinical practice without the complete validation usually required by the regulatory organizations.MethodsSARS-CoV-2 patient samples (n=43) were analysed alongside pre-pandemic control specimen (n=50), confirmed respiratory infections (n=50), inflammatory polyarthritis (n=22) and positive for thyroid stimulating immunoglobulin (n=30). Imprecision, diagnostic sensitivity and specificity and concordance were evaluated on IgG serologic assays from EuroImmun, Epitope Diagnostics (EDI), Abbott Diagnostics and DiaSorin and a rapid IgG/IgM test from Healgen.ResultsEDI and EuroImmun imprecision was 0.02-14.0% CV. Abbott and DiaSorin imprecision (CV) ranged from 5.2% - 8.1% and 8.2% - 9.6% respectively. Diagnostic sensitivity of the assays were 100% (CI: 80-100%) for Abbott, EDI and EuroImmun and 95% (CI: 73-100%) for DiaSorin at ≥14 days post PCR. Only the Abbott assay had a diagnostic specificity of 100% (CI: 91-100%). EuroImmun cross-reacted in 3 non-SARS-CoV-2 respiratory infections and 2 controls. The DiaSorin displayed more false negative results and cross-reacted in six cases across all conditions tested. EDI had one cross-reactive sample. The Healgen rapid test showed excellent sensitivity and specificity. Overall, concordance of the assays ranged from 76.1% to 97.9%.ConclusionsSerological tests for SARS-CoV-2 showed good analytical performance. The head-to-head analysis of samples revealed differences in results that may be linked to the use of nucleocapsid or spike proteins. The point of care device tested demonstrated adequate performance for antibody detection.

scholarly journals Improved Diagnosis of Tuberculous Meningitis Using a Combination of Multiplex Antigens and Antibodies Testing Methods

2021 ◽  
Author(s):  
Amit Raju Nayak ◽  
Payal Rajendra Khulkhule ◽  
Vinita Rajendra Hutke ◽  
Arti Ramkumar Mishra ◽  
Nitin Harinarayan Chandak ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Blood Sugar ◽  
Tuberculous Meningitis ◽  
Central India ◽  
Antigen Detection ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
P Value ◽  
Antibody Assay ◽  
Neck Stiffness

Introduction: Various serological assays exists, including Antigen and Antibody detection (IgM and IgG) for diagnosis of Tuberculous Meningitis (TBM) cases. To the best of our knowledge, most of the laboratories either do Antigen detection or IgM or IgG, at a time. As different antigens get expressed in a different stage of infection it may be possible that many cases remain undiagnosed due to one test at a time approach. Aim: To evaluate the combination of Mycobacterium Tuberculosis (MTB) antigen (Ag85 Complex and Rv2623) and antibody (Anti-Ag85, Anti-45kD, Anti-HSP-16, Anti-CFP-10 Anti-GroES and Anti-ESAT-6) immunoassay panels in the Cerebrospinal Fluid (CSF) samples for diagnosis of TBM patient. Materials and Methods: In the present prospective study conducted at Central India Institute of Medical Sciences (CIIMS) from October 2013 to April 2015, a total of 200 CSF samples of different groups {confirmed TBM (n=100) and noninfectious neurological diseases as control (n=100)} were analysed by Enzyme-Linked Immunosorbent Assay (ELISA). A panel of MTB antigens consisting of Ag85B, 45kDa, HSP-16, CFP-10, GroES and ESAT-6 were used for detection of antibodies response, whereas polyclonal antibodies were used for antigen detection of Ag85 complex and Rv2623 in the CSF samples. The comparison of the CSF parameter between TBM and non-TBM patients was performed using a student t-test. A p-value <0.05 was considered statistically significant for all the analyses. Results: The study population has similar age and sex distribution (p>0.05). Symptoms of headache, fever, neck stiffness, vomiting, abnormal behaviour, unconsciousness were more common among the TBM patients as compared to non-TBM patients (p<0.05) (TBM Vs non-TBM). Similarly TBM patients had an increase (p<0.05) Vs non-TBM total cell count, protein, parallel blood sugar and decline in CSF sugar and Parallel blood sugar ratio (p<0.05) (TBM Vs non-TBM). We found diagnostic accuracy of 67% to 76% with either antigen or antibody assay, however, combinations of antigen and antibody immunoassay together increase the diagnostic accuracy of up to 96%. Conclusion: Our study recommends that a combination of antigen and antibody assay should be considered for early and accurate diagnosis of TBM cases.

scholarly journals Highly Sensitive and Specific SARS-CoV-2 Serological Assay Using a Magnetic Modulation Biosensing System

Biosensors ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Shira Avivi-Mintz ◽  
Yaniv Lustig ◽  
Victoria Indenbaum ◽  
Eli Schwartz ◽  
Amos Danielli
Keyword(s):  
Viral Infections ◽  
Limit Of Detection ◽  
Turnaround Time ◽  
Elisa Test ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Serological Assay ◽  
Clinical Sensitivity ◽  
Highly Sensitive

Sensitive serological assays are needed to provide valuable information about acute and past viral infections. For example, detection of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies could serve as the basis for an “immunity passport” that would enable individuals to travel internationally. Here, utilizing a novel Magnetic Modulation Biosensing (MMB) system and the receptor-binding domain of the SARS-CoV-2 spike protein, we demonstrate a highly sensitive and specific anti-SARS-CoV-2 IgG serological assay. Using anti-SARS-CoV-2 IgG antibodies, RT-qPCR SARS-CoV-2-positive and healthy patients’ samples, and vaccinees’ samples, we compare the MMB-based SARS-CoV-2 IgG assay’s analytical and clinical sensitivities to those of the enzyme-linked immunosorbent assay (ELISA). Compared with ELISA, the MMB-based assay has an ~6-fold lower limit of detection (129 ng/L vs. 817 ng/L), and it detects an increase in the IgG concentration much earlier after vaccination. Using 85 RT-qPCR SARS-CoV-2-positive samples and 79 -negative samples, the MMB-based assay demonstrated similar clinical specificity (98% vs. 99%) and sensitivity (93% vs. 92%) to the ELISA test, but with a much faster turnaround time (45 min vs. 245 min). The high analytical and clinical sensitivity, short turnaround time, and simplicity of the MMB-based assay makes it a preferred method for antibody detection.

scholarly journals Evaluation of the diagnostic accuracy of a new point-of-care rapid test for SARS-CoV-2 virus detection

2020 ◽  
Author(s):  
Leonardo Miscio ◽  
Antonio Olivieri ◽  
Francesco Labonia ◽  
Gianfranco De Feo ◽  
Paolo Chiodini ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Real Time ◽  
Real Time Pcr ◽  
Point Of Care ◽  
Virus Detection ◽  
Rapid Test ◽  
Reference Method ◽  
Standard Of Care ◽  
Easy Access ◽  
Diagnostic Tools

Abstract Background: The easy access to a quick diagnosis of coronavirus disease 2019 (COVID-19) is a key point to improve the management of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and to contain its spread. Up to now, laboratory real-time PCR is the standard of care, but requires a fully equipped laboratory and significant infrastructure. Consequently, new diagnostic tools are required. Methods: In the present work, the diagnostic accuracy of the point-of-care rapid test "bKIT Virus Finder COVID-19" (Hyris Ltd) is evaluated by a retrospective and a prospective analysis on SARS CoV-2 samples previously assessed with an FDA “authorized for the emergency use - EUA” reference method. Descriptive statistics were used for the present study.Results: Results obtained with the Hyris Kit are the same as that of standard laboratory-based real time PCR methods for all the analyzed samples. In addition, the Hyris Kit provides the test results in less than 2 hours, a significantly shorter time compared to the reference methods, without the need of a fully equipped laboratory. Conclusions: To conclude, the Hyris kit represents a promising tool to improve the health surveillance and to increase the capacity of SARS-CoV-2 testing.

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

PLoS ONE ◽  
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.

scholarly journals Dynamic characteristic of SARS-CoV-2 and its antibody detection

2021 ◽  
Vol 7 (4) ◽  
pp. 100-101
Author(s):  
Bahrul Fikri ◽  
◽  
Andi Dwi Bahagia Febriani ◽  
Muhamad Ali ◽  
Nasrum Massi ◽  
...  
Keyword(s):  
Point Of Care ◽  
Diagnostic Testing ◽  
Rapid Test ◽  
Turnaround Time ◽  
Antibody Detection ◽  
Point Of Care Test ◽  
Specimen Collection ◽  
Excess Morbidity ◽  
Sensitivity Specificity ◽  
Testing Solution

To prevent excess morbidity and mortality of Covid-19, a prompt and accurate diagnosis is crucial. Antibody-based rapid diagnostic test (RDT) is a rapid, fairly reliable, and useful diagnostic testing solution for COVID-19. As a point-of-care test with fast turnaround time, the kit permits quick screening in hospitals to avoid the crowding of specimen collection. However, available RDTs kits have different sensitivity, specificity, and accuracy profiles due to antigen and antibody variability because of the sequence mutation of the SARS-CoV-2 gene. Therefore, it is strongly recommended to either re-measure the accuracy of a rapid test before using it in a different country or use tests developed based on local viral characteristics

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