scholarly journals Diagnostic Efficiency of Three Fully Automated Serology Assays and Their Correlation with a Novel Surrogate Virus Neutralization Test in Symptomatic and Asymptomatic SARS-COV-2 Individuals

2021 ◽  
Vol 9 (2) ◽  
pp. 245
Author(s):  
Salma Younes ◽  
Hadeel Al-Jighefee ◽  
Farah Shurrab ◽  
Duaa W. Al-Sadeq ◽  
Nadin Younes ◽  
...  
Keyword(s):  
Diagnostic Performance ◽  
Neutralization Test ◽  
Cross Reactivity ◽  
Diagnostic Efficiency ◽  
Receptor Binding Domain ◽  
Rt Pcr ◽  
Viral Antibodies ◽  
Asymptomatic Patients ◽  
Intended Use ◽  
Control Samples

To support the deployment of serology assays for population screening during the COVID-19 pandemic, we compared the performance of three fully automated SARS-CoV-2 IgG assays: Mindray CL-900i® (target: spike [S] and nucleocapsid [N]), BioMérieux VIDAS®3 (target: receptor-binding domain [RBD]) and Diasorin LIAISON®XL (target: S1 and S2 subunits). A total of 111 SARS-CoV-2 RT-PCR- positive samples collected at ≥ 21 days post symptom onset, and 127 pre-pandemic control samples were included. Diagnostic performance was assessed in correlation to RT-PCR and a surrogate virus-neutralizing test (sVNT). Moreover, cross-reactivity with other viral antibodies was investigated. Compared to RT-PCR, LIAISON®XL showed the highest overall specificity (100%), followed by VIDAS®3 (98.4%) and CL-900i® (95.3%). The highest sensitivity was demonstrated by CL-900i® (90.1%), followed by VIDAS®3 (88.3%) and LIAISON®XL (85.6%). The sensitivity of all assays was higher in symptomatic patients (91.1–98.2%) compared to asymptomatic patients (78.4–80.4%). In correlation to sVNT, all assays showed excellent sensitivities (92.2–96.1%). In addition, VIDAS®3 demonstrated the best correlation (r = 0.75) with the sVNT. The present study provides insights on the performance of three fully automated assays, which could help diagnostic laboratories in the choice of a particular assay according to the intended use.

scholarly journals Automated Western immunoblotting detection of anti-SARS-CoV-2 serum antibodies

2021 ◽  
Author(s):  
Sophie Edouard ◽  
Rita Jaafar ◽  
Nicolas Orain ◽  
Philippe Parola ◽  
Philippe Colson ◽  
...  
Keyword(s):  
Negative Control ◽  
Cross Reactivity ◽  
Spike Protein ◽  
Rt Pcr ◽  
Substantial Agreement ◽  
Western Immunoblotting ◽  
Elisa Kit ◽  
Line Test ◽  
Serologic Assay ◽  
Control Samples

AbstractELISA and chemiluminescence serological assays for COVID-19 are currently incorporating only one or two SARS-CoV-2 antigens. We developed an automated Western immunoblotting as a complementary serologic assay for COVID-19. The JessTM Simple Western system, an automated capillary-based assay, was used, incorporating an inactivated SARS-CoV-2 lineage 20a strain as the source of antigen, and total immunoglobulins (IgG, IgM, IgA) detection. In total, 602 sera were tested including 223 from RT-PCR-confirmed COVID-19 patients, 76 from patients diagnosed with seasonal HCoVs and 303 from coronavirus-negative control sera. We also compared this assay with the EUROIMMUN® SARS-CoV-2 IgG ELISA kit. Among 223 sera obtained from RT-PCR-confirmed COVID-19 patients, 180/223 (81%) exhibited reactivity against the nucleocapsid and 70/223 (31%) against the spike protein. Nucleocapsid reactivity was further detected in 9/76 (14%) samples collected from patients diagnosed with seasonal HCoVs and in 15/303 (5%) coronavirus-negative control samples. In the subset of sera collected more than 2 weeks after the onset of symptoms, the sensitivity was 94% and the specificity 93%, the latter value probably reflecting cross-reactivity of SARS-CoV-2 with other coronaviruses. The automated Western immunoblotting presented a substantial agreement (90%) with the compared ELISA (Cohen’s Kappa=0.64). Automated Western immunoblotting may be used as a second line test to monitor exposure of people to HCoVs including SARS-CoV-2.

scholarly journals Validation of Selected Commercial Serological Assays for Diagnosis of COVID-19

2020 ◽  
Author(s):  
Salma Younes ◽  
Hadeel Al-Jighefee ◽  
Farah Shurrab ◽  
Duaa Al-Sadeq ◽  
Hadi Yassine ◽  
...  
Keyword(s):  
Neutralization Test ◽  
Cross Reactivity ◽  
Clinical Settings ◽  
Igg Antibodies ◽  
Excellent Correlation ◽  
Rt Pcr ◽  
Rapid Assays ◽  
Igm Elisa ◽  
Rapid Tests ◽  
Antibody Tests

As researchers around the globe rush to put the available antibody tests to use, concerns have been raised about their precision. This study aimed to evaluate and compare the performance of selected commercial & automated serological assays that are widely used in different clinical settings in Qatar. We validated the performance of five commercial IgG and IgM ELISA kits, three fully automated immunoassays, and two commercial rapid tests. The sensitivity of all assays was compared to RT-PCR and a surrogate virus neutralization test (sVNT). In addition, cross-reactivity was investigated. Among the evaluated kits, Lionex IgG assay demonstrated the best performance (~88% sensitivity and ~99 specificity). All automated assays showed an excellent correlation with the neutralization test with an overall agreement of 93.6-98.5%. The rapid assays demonstrated a very good performance in detecting IgG antibodies (86.0-88.0% sensitivity and 98.0-100% specificity).

scholarly journals Diagnostic performance of a novel digital immunoassay (RapidTesta SARS-CoV-2): a prospective observational study with 1,127 nasopharyngeal samples

2021 ◽  
Author(s):  
Hiromichi Suzuki ◽  
Yusaku Akashi ◽  
Atsuo Ueda ◽  
Yoshihiko Kiyasu ◽  
Yuto Takeuchi ◽  
...  
Keyword(s):  
Diagnostic Performance ◽  
Prospective Observational Study ◽  
Test Results ◽  
Antigen Test ◽  
Rt Pcr ◽  
Asymptomatic Patients ◽  
Pcr Method ◽  
Antigen Tests ◽  
Positive Line ◽  
Test Cassette

Introduction: Digital immunoassays are generally regarded as superior tests for the detection of infectious disease pathogens, but there have been insufficient data concerning SARS-CoV-2 immunoassays. Methods: We prospectively evaluated a novel digital immunoassay (RapidTesta SARS-CoV-2). Two nasopharyngeal samples were simultaneously collected for antigen tests and RT-PCR. Real-time RT-PCR for SARS-CoV-2, using a method developed by the National Institute of Infectious Diseases, Japan, served as the reference RT-PCR method. Results: During the study period, 1,127 nasopharyngeal samples (symptomatic patients: 802, asymptomatic patients: 325) were evaluated. For digital immunoassay antigen tests, the sensitivity was 78.3% (95% CI: 67.3%-87.1%) and the specificity was 97.6% (95% CI: 96.5%-98.5%). When technicians visually analyzed the antigen test results, the sensitivity was 71.6% (95% CI: 59.9%-81.5%) and the specificity was 99.2% (95% CI: 98.5%-99.7%). Among symptomatic patients, the sensitivity was 89.4% (95% CI; 76.9%-96.5%) with digital immunoassay antigen tests, and 85.1% (95% CI; 71.7%-93.8%) with visually analyzed the antigen test, respectively. Conclusions: The findings indicated that RapidTesta SARS-CoV-2 analysis with the DIA device had sufficient analytical performance for the detection of SARS-CoV-2 in nasopharyngeal samples. When positive DIA results are recorded without a visually recognizable red line at the positive line location on the test cassette, additional RT-PCR evaluation should be performed.

scholarly journals Diagnostic performance of anti-Zika virus IgM, IgAM and IgG ELISAs during co-circulation of Zika, dengue, and chikungunya viruses in Brazil and Venezuela

2021 ◽  
Vol 15 (4) ◽  
pp. e0009336
Author(s):  
Ivonne Morales ◽  
Kerstin D. Rosenberger ◽  
Tereza Magalhaes ◽  
Clarice N. L. Morais ◽  
Cynthia Braga ◽  
...  
Keyword(s):  
Zika Virus ◽  
Test Performance ◽  
Diagnostic Performance ◽  
Cross Reactivity ◽  
Rt Pcr ◽  
Zikv Infection ◽  
Serological Tests ◽  
Sequential Samples

Background Serological diagnosis of Zika virus (ZIKV) infection is challenging because of the antibody cross-reactivity among flaviviruses. At the same time, the role of Nucleic Acid Testing (NAT) is limited by the low proportion of symptomatic infections and the low average viral load. Here, we compared the diagnostic performance of commercially available IgM, IgAM, and IgG ELISAs in sequential samples during the ZIKV and chikungunya (CHIKV) epidemics and co-circulation of dengue virus (DENV) in Brazil and Venezuela. Methodology/Principal findings Acute (day of illness 1–5) and follow-up (day of illness ≥ 6) blood samples were collected from nine hundred and seven symptomatic patients enrolled in a prospective multicenter study of symptomatic patients recruited between June 2012 and August 2016. Acute samples were tested by RT-PCR for ZIKV, DENV, and CHIKV. Acute and follow-up samples were tested for IgM, IgAM, and IgG antibodies to ZIKV using commercially available ELISAs. Among follow-up samples with a RT-PCR confirmed ZIKV infection, anti-ZIKV IgAM sensitivity was 93.5% (43/48), while IgM and IgG exhibited sensitivities of 30.3% (10/35) and 72% (18/25), respectively. An additional 24% (26/109) of ZIKV infections were detected via IgAM seroconversion in ZIKV/DENV/CHIKV RT-PCR negative patients. The specificity of anti-ZIKV IgM was estimated at 93% and that of IgAM at 85%. Conclusions/Significance Our findings exemplify the challenges of the assessment of test performance for ZIKV serological tests in the real-world setting, during co-circulation of DENV, ZIKV, and CHIKV. However, we can also demonstrate that the IgAM immunoassay exhibits superior sensitivity to detect ZIKV RT-PCR confirmed infections compared to IgG and IgM immunoassays. The IgAM assay also proves to be promising for detection of anti-ZIKV seroconversions in sequential samples, both in ZIKV PCR-positive as well as PCR-negative patients, making this a candidate assay for serological monitoring of pregnant women in future ZIKV outbreaks.

Inkoo And Sindbis Viruses In Semi-Domesticated Reindeer And Mosquitoes In Norway

2021 ◽  
Author(s):  
Ruchika Shakya ◽  
Morten Tryland ◽  
Rose Vikse ◽  
Javier Sánchez Romano ◽  
Kjetil Åsbakk ◽  
...  
Keyword(s):  
Rangifer Tarandus ◽  
Neutralization Test ◽  
Cross Reactivity ◽  
Immunofluorescence Assay ◽  
Rt Pcr ◽  
High Seroprevalence ◽  
Real Time Quantitative Pcr ◽  
Summer Pasture ◽  
Specific Igg ◽  
Pool Prevalence

Abstract Background: Mosquito-borne viruses pose a serious threat to humans worldwide. There has been an upsurge in the number of mosquito-borne viruses in Europe, mostly belonging to the families Togaviridae (Sindbis, Chikungunya), Flaviviridae (West Nile, Usutu, Dengue), and Peribunyaviridae (Inkoo, Batai, Tahyna). The principal focus of this study was Inkoo (INKV) and Sindbis (SINV) virus circulating in Norway because there is a knowledge gap regarding reservoirs and transmission. Therefore, we aimed to determine the prevalence of SINV and INKV in mosquitoes and seroprevalence of INKV in semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus).Methods: In total, 213 pools containing about 25 mosquitoes each and 480 reindeer sera were collected in eight Norwegian reindeer summer pasture districts during 2013-2015. The mosquito pools were analysed for INKV and SINV RNA, with reverse transcriptase (RT)-real time quantitative PCR (RT-qPCR), and pyrosequencing. Reindeer sera were analysed for INKV-specific IgG by Indirect Immunofluorescence Assay (IIFA) and Plaque Reduction Neutralization Test (PRNT).Results: Aedes spp. were the most dominant species among the collected mosquitoes. Two of the mosquito pools were positive for INKV-RNA by RT-PCR and were confirmed by pyrosequencing. The overall estimated pool prevalence (EPP) of INKV in Norway was 0.04%. IgG seroprevalence in reindeer revealed 60% positive for INKV by IIFA. Of the 55 borderline reindeer sera, 24% were positive on cytopathic effect (CPE)-neutralization test. Among 80% of 60 reindeer sera analysed with PRNT for INKV had a titre ≥ 20, and there was no cross-reactivity with the closely related Tahyna virus (TAHV) and Snow Shoe Hare virus (SSHV). None of the analysed mosquito pools were positive for SINV.Conclusions: The occurrence and prevalence of INKV in Aedes mosquitoes and its high seroprevalence among semi-domesticated reindeer in Norway indicate that further studies are required for monitoring this virus. SINV was not detected in the mosquitoes in this study, however, human cases of SINV infection have yearly been reported from Rjukan. Therefore, it is essential to investigate SINV among human population. Our findings are important to raise awareness regarding the geographical distribution of these mosquito-borne viruses in Northern Europe.

scholarly journals Automated Western immunoblotting detection of anti-SARS-CoV-2 serum antibodies

2020 ◽  
Author(s):  
S. Edouard ◽  
R. Jaafar ◽  
N. Orain ◽  
P. Parola ◽  
P. Colson ◽  
...  
Keyword(s):  
Negative Control ◽  
Cross Reactivity ◽  
Spike Protein ◽  
Rt Pcr ◽  
Substantial Agreement ◽  
Western Immunoblotting ◽  
Elisa Kit ◽  
Line Test ◽  
Serologic Assay ◽  
Control Samples

ABSTRACTELISA and chemiluminescence serological assays for COVID-19 are currently incorporating only one or two SARS-CoV-2 antigens. We developed an automated Western immunoblotting as a complementary serologic assay for COVID-19. The Jess™ Simple Western system, an automated capillary-based assay was used, incorporating an inactivated SARS-CoV-2 lineage 20a strain as antigen, and IgT detection. In total, 602 sera were tested including 223 from RT-PCR-confirmed COVID-19 patients, 76 from patients diagnosed with seasonal HCoVs and 303 from coronavirus-negative control sera. We also compared this assay with the EUROIMMUN® SARS-CoV-2 IgG ELISA kit. Among 223 sera obtained from RT-PCR-confirmed COVID-19 patients, 180/223 (81%) exhibited reactivity against the nucleocapsid and 70/223 (31%) against the spike protein. Nucleocapsid reactivity was further detected in 9/76 (14%) samples collected from patients diagnosed with seasonal HCoVs and in 15/303 (5%) coronavirus-negative control samples. In the subset of sera collected more than 2 weeks after the onset of symptoms, the sensitivity was 94% and the specificity 93%, the latter value probably reflecting cross-reactivity of SARS-CoV-2 with other coronaviruses. The automated Western immunoblotting presented a substantial agreement (90%) with the compared ELISA (Cohen’s Kappa=0.64). Automated Western immunoblotting may be used as a second line test to monitor exposition of people to HCoVs including SARS-CoV-2.

scholarly journals Systematic evaluation of IgG responses to SARS-CoV-2 spike protein-derived peptides for monitoring COVID-19 patients

2021 ◽  
Author(s):  
Yang Li ◽  
Dan-yun Lai ◽  
Qing Lei ◽  
Zhao-wei Xu ◽  
Feng Wang ◽  
...  
Keyword(s):  
Diagnostic Performance ◽  
Protein Production ◽  
Protein S ◽  
Cross Reactivity ◽  
Spike Protein ◽  
Systematic Evaluation ◽  
Serological Tests ◽  
S Protein ◽  
Asymptomatic Patients ◽  
Human Coronaviruses

AbstractSerological tests play an essential role in monitoring and combating the COVID-19 pandemic. Recombinant spike protein (S protein), especially the S1 protein, is one of the major reagents used for serological tests. However, the high cost of S protein production and possible cross-reactivity with other human coronaviruses pose unavoidable challenges. By taking advantage of a peptide microarray with full spike protein coverage, we analyzed 2,434 sera from 858 COVID-19 patients, 63 asymptomatic patients and 610 controls collected from multiple clinical centers. Based on the results, we identified several S protein-derived 12-mer peptides that have high diagnostic performance. In particular, for monitoring the IgG response, one peptide (aa 1148–1159 or S2–78) exhibited a sensitivity (95.5%, 95% CI 93.7–96.9%) and specificity (96.7%, 95% CI 94.8–98.0%) comparable to those of the S1 protein for the detection of both symptomatic and asymptomatic COVID-19 cases. Furthermore, the diagnostic performance of the S2–78 (aa 1148–1159) IgG was successfully validated by ELISA in an independent sample cohort. A panel of four peptides, S1–93 (aa 553–564), S1–97 (aa 577–588), S1–101 (aa 601–612) and S1–105 (aa 625–636), that likely will avoid potential cross-reactivity with sera from patients infected by other coronaviruses was constructed. The peptides identified in this study may be applied independently or in combination with the S1 protein for accurate, affordable, and accessible COVID-19 diagnosis.

scholarly journals Implementing SARS-CoV-2 Rapid Antigen Testing in the Emergency Ward of a Swiss University Hospital: The INCREASE Study

2021 ◽  
Vol 9 (4) ◽  
pp. 798
Author(s):  
Giorgia Caruana ◽  
Antony Croxatto ◽  
Eleftheria Kampouri ◽  
Antonios Kritikos ◽  
Onya Opota ◽  
...  
Keyword(s):  
Immunoglobulin A ◽  
University Hospital ◽  
Lower Sensitivity ◽  
Clinical Settings ◽  
Rt Pcr ◽  
Emergency Ward ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Asymptomatic Subjects ◽  
Antigen Testing

Following the Swiss Federal Office of Public Health (FOPH) authorization of the rapid antigen test (RAT), we implemented the use of the RAT in the emergency ward of our university hospital for patients’ cohorting. RAT triaging in association with RT-PCR allowed us to promptly isolate positive patients and save resources. Among 532 patients, overall sensitivities were 48.3% for Exdia and 41.2% for Standard Q®, PanbioTM and BD Veritor™. All RATs exhibited specificity above 99%. Sensitivity increased to 74.6%, 66.2%, 66.2% and 64.8% for Exdia, Standard Q®, PanbioTM and BD Veritor™, respectively, for viral loads above 105 copies/mL, to 100%, 97.8%, 96.6% and 95.6% for viral loads above 106 copies/mL and 100% for viral loads above 107 copies/mL. Sensitivity was significantly higher for patients with symptoms onset within four days (74.3%, 69.2%, 69.2% and 64%, respectively) versus patients with the evolution of symptoms longer than four days (36.8%, 21.1%, 21.1% and 23.7%, respectively). Among COVID-19 asymptomatic patients, sensitivity was 33%. All Immunoglobulin-A-positive patients resulted negative for RAT. The RAT might represent a useful resource in selected clinical settings as a complementary tool in RT-PCR for rapid patient triaging, but the lower sensitivity, especially in late presenters and COVID-19 asymptomatic subjects, must be taken into account.

scholarly journals Diagnostic performance of different sampling approaches for SARS-CoV-2 RT-PCR testing: a systematic review and meta-analysis

2021 ◽  
Author(s):  
Nicole Ngai Yung Tsang ◽  
Hau Chi So ◽  
Ka Yan Ng ◽  
Benjamin J Cowling ◽  
Gabriel M Leung ◽  
...  
Keyword(s):  
Systematic Review ◽  
Diagnostic Performance ◽  
Meta Analysis ◽  
Rt Pcr
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