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

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.

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Performance analysis of rapid diagnostic tests on atypical bovine spongiform encephalopathy

Journal of Veterinary Diagnostic Investigation ◽

10.1177/1040638712455325 ◽

2012 ◽

Vol 24 (5) ◽

pp. 976-980 ◽

Cited By ~ 6

Author(s):

John G. Gray ◽

Sandor Dudas ◽

Catherine Graham ◽

Stefanie Czub

Keyword(s):

Bovine Spongiform Encephalopathy ◽

Test Performance ◽

Rapid Test ◽

Rapid Diagnostic Tests ◽

Enzyme Linked Immunosorbent Assay ◽

Spongiform Encephalopathy ◽

Analytical Sensitivity ◽

Atypical Bovine Spongiform Encephalopathy ◽

Surveillance Programs ◽

Rapid Tests

The preferred method to determine the prevalence of bovine spongiform encephalopathy (BSE) in a country is to use immunology-based rapid-tests. Though these tests are validated to detect C-type BSE disease–associated prion (PrPsc), test-specific properties may influence their ability to detect H- and/or L-type BSE PrPsc, where both are atypical from C-type PrPsc. Molecular characterization shows atypical BSE PrPsc to have a different sensitivity to proteinase activity and different affinities for certain prion-specific antibodies. It is important to understand how atypical BSE PrPsc may affect the performance of rapid-tests, which are typically dependant on the use of specific proteases and antibodies. The current study used experimentally generated C-, H-, and L-type BSE PrPsc to evaluate 3 tests used in various national BSE surveillance programs: an immunochromatographic assay, a standard sandwich enzyme-linked immunosorbent assay (stndELISA), and a PrPsc-conformation–specific ELISA (confELISA). Although BSE PrPsc type had some effects on rapid-test performance, analytical sensitivity for atypical BSE PrPsc on all 3 platforms was not significantly compromised. When testing for atypical BSE PrPsc, the 3 tests were able to meet the same requirements that the European Food Safety Authority set when evaluating the tests for C-type BSE PrPsc.

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Comparison of Three Enzyme-Linked Immunosorbent Assays for Serologic Diagnosis of Contagious Agalactia in Sheep

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063870301500311 ◽

2003 ◽

Vol 15 (3) ◽

pp. 281-285 ◽

Cited By ~ 6

Author(s):

Michel Pépin ◽

Philippe Dufour ◽

Maurice Lambert ◽

Michel Aubert ◽

Aurèle Valognes ◽

...

Keyword(s):

False Negative ◽

Good Alternative ◽

Enzyme Linked Immunosorbent Assay ◽

Analytical Sensitivity ◽

Diagnostic Specificity ◽

True Negative ◽

Serologic Diagnosis ◽

Contagious Agalactia ◽

Kappa Value ◽

Kinetics Of

Serologic diagnosis of ovine contagious agalactia ( Mycoplasma agalactiae) with the enzyme-linked immunosorbent assay (ELISA) developed by Agence Française de Séceurité Sanitaire des Aliments (AFS-SA) may produce a few false-positive (FP) and false-negative (FN) results. When the prevalence of disease is low, these erroneous results may generate problems for eradication schemes. To prevent this, 2 commercial ELISAs were compared with the AFSSA ELISA. Flocks of known status were selected and classified into 4 categories: true positive (TP), FP, true negative (TN), and FN; 20 sheep per flock were submitted for blood sampling. A flock was considered positive when at least 1 out of 20 sera was positive or 2 sera were doubtful. In the flock, the diagnostic sensitivity of the 3 kits was very good (100%), and the diagnostic specificity showed an improvement from 46% (AFSSA test) to 88% and 92% (commercial tests). Considering individual animals, very few positive ewes were detected within TN or FP flocks; the proportion of positive ewes varied greatly from one kit to another (48% to 82%) within TP flocks. The kinetics of antibody response in sheep experimentally infected with various field strains of M. agalactiae were quite similar with all 3 ELISAs. The agreement between the 3 tests, assessed using the kappa value, varied from moderate to good (respective values of 0.56, 0.61, and 0.86). The 2 commercial ELISAs showed better performances, probably because of a superior analytical sensitivity, and are a good alternative for the serodiagnosis of contagious agalactia in sheep.

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False negative HIV antibody test in HIV infected children who receive early antiretroviral treatment in a resource-limited setting

Infectious Disease Reports ◽

10.4081/idr.2012.3832 ◽

2012 ◽

Vol 4 (1) ◽

pp. 6 ◽

Cited By ~ 1

Author(s):

Gerardo Alvarez-Uria ◽

Praveen K. Naik ◽

Manoranjan Midde ◽

Shanmugamari Kannan ◽

Raghuprakash Reddy

Keyword(s):

False Negative ◽

Rapid Test ◽

Antibody Test ◽

Rural Setting ◽

World Health ◽

Enzyme Linked Immunosorbent Assay ◽

Resource Limited ◽

One Year ◽

Health Organization ◽

Early Antiretroviral Treatment

<p>With the implementation of 2010 World Health Organization guidelines, the number of infants from developing countries who will initiate antiretroviral therapy (ART) will increase considerably. In this study we describe the HIV antibody tests of 14 HIV infected children who initiated ART at age less than one year in a rural setting of India. The HIV rapid test was negative in seven and indeterminate in two cases, whereas the HIV enzyme-linked immunosorbent assay (ELISA) antibody test was negative in three and indeterminate in one case. In one child who had both negative HIV rapid test and ELISA initially, HIV serology turned positive after having a virological failure to ART, suggesting the possibility of utilizing HIV serology for monitoring ART effectiveness in children who experience HIV seroreversion. In conclusion, HIV seroreversion of children with early initiation of ART is common and should be considered for avoiding misdiagnosis of HIV infection.</p><p> </p>

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Acceptability of dual HIV/syphilis rapid test in community- and home-based testing strategy among transgender women in Buenos Aires, Argentina

International Journal of STD & AIDS ◽

10.1177/0956462420979852 ◽

2021 ◽

Vol 32 (6) ◽

pp. 501-509

Author(s):

Virginia Zalazar ◽

Claudia E Frola ◽

Ana Gun ◽

Pablo D Radusky ◽

Natalia K Panis ◽

...

Keyword(s):

Buenos Aires ◽

Treatment Initiation ◽

Rapid Test ◽

Transgender Women ◽

Hiv Positive ◽

Testing Strategy ◽

Treatment Uptake ◽

Home Based ◽

Rapid Tests ◽

Positive Results

Background: Little is known of acceptability and feasibility of dual HIV and syphilis rapid tests in community- and home-based provider-initiated strategies among transgender women (TGW), in Latin America. Objectives were (1) to assess the acceptability of this strategy and, (2) to determine the percentage of positive results of HIV and syphilis, analyze the correlates of HIV or syphilis positive results, and measure the rates of effective referral and treatment completion among TGW. Methods: A multidisciplinary team tested 89 TGW in Buenos Aires. An acceptability survey was administered after the HIV/syphilis Duo test was used. All confirmed cases were referred for treatment initiation. Results: We found high levels of acceptability (98.8%) of this strategy among TGW. However, only 60.7% preferred simultaneous HIV and syphilis diagnosis test. Moreover, we found 9% of positive results of HIV, 51.7% of syphilis, and 3.4% of positive results for both infections. Only not being tested before was associated with an HIV positive result, and only low level of education was associated with a positive syphilis result. Among 8 TGW who tested positive for HIV, 37.5% ( n = 3) started antiretroviral therapy. Of 46 who tested positive for syphilis, only 73.9% ( n = 34) were effectively referred and from 23 who started treatment, only 39.1% completed it. Conclusions: Community- and home-based dual HIV and syphilis rapid test is a feasible and highly acceptable approach for this hard-to-reach population. Implementing similar strategies could improve screening uptake and accessibility. However, these results highlight the need to improve strategies for treatment uptake, in order to reduce morbidity and risk of onward transmission.

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Line immunoassay for detection of IgG antibodies to hepatitis E virus (Hepeviridae, Orthohepevirus, Orthohepevirus A)

Voprosy Virusologii ◽

10.36233/0507-4088-2020-65-3-132-142 ◽

2020 ◽

Vol 65 (3) ◽

pp. 132-142

Author(s):

G. I. Alatortseva ◽

V. V. Dotsenko ◽

L. N. Nesterenko ◽

L. N. Luhverchik ◽

V. Yu. Kabargina ◽

...

Keyword(s):

Human Serum ◽

Hepatitis E Virus ◽

Hepatitis E ◽

Test System ◽

Enzyme Linked Immunosorbent Assay ◽

Analytical Sensitivity ◽

Igg Antibodies ◽

Recombinant Antigens ◽

Test Kit ◽

Wide Range

Introduction. The diagnostic efficacy of methods for hepatitis E serodiagnostic varies over a wide range; therefore, the combined use of tests of various formats is recommended. The aim of the research was to develop a test system for the detection of IgG antibodies to hepatitis E virus (HEV) in human serum by linear immunoassay (LIA). Material and methods. Serum samples from patients with hepatitis and healthy individuals were tested using commercial enzyme-linked immunosorbent assay systems for the presence of IgG antibodies to viral agents causing hepatitis and other infections associated with liver pathology. Recombinant antigens ORF2 and ORF3 of HEV genotypes 1 and 3 were used. The “RecomLine HEV IgG/IgM” reagent kit (Mikrogen GmbH, Germany) was used as a comparison test system. Results. The first Russian diagnostic kit “Blot-HEV”, designed to detect IgG antibodies to individual HEV proteins in human serum using LIA, was developed. The antigenic base is represented by strips of a nitrocellulose membrane with immobilized recombinant antigens ORF2 (aa 406–660) and ORF3 (aa 1–113) of HEV genotypes 1 and 3, and control antigens in the form of discrete lines. The conjugate was mouse monoclonal antibodies to human class G immunoglobulins labeled with horseradish peroxidase. The chromogen solution contained the 3,3’,5,5’-tetramethylbenzidine. A visual and digital recording of results was provided. The analytical sensitivity of the test kit was 0.625 IU/ml for ORF2 antigens and 2.5 IU/ml for ORF3 antigens. The absence of the influence of endogenous interfering substances on the results of the analysis and the absence of cross-reactions with antibodies to hepatitis pathogens of the other etiologies had been shown. The sensitivity of the test system compared to the “RecomLine HEV IgG/IgM” kit was 92%, specificity 97%. Shelf life in condition of storage was determined to be 12 months. Conclusions. The developed test can be used to confirm the results of ELISA in laboratory diagnosis of hepatitis E.

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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

10.21203/rs.3.rs-50887/v1 ◽

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.

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An improved test system for PCR-based specific detection ofEchinococcus multiloculariseggs

Journal of Helminthology ◽

10.1017/s0022149x00015443 ◽

1996 ◽

Vol 70 (3) ◽

pp. 219-222 ◽

Cited By ~ 138

Author(s):

A. Mathis ◽

P. Deplazes ◽

J. Eckert

Keyword(s):

False Negative ◽

Test System ◽

Specific Primers ◽

Alkaline Lysis ◽

Negative Results ◽

False Negative Results ◽

Faecal Samples ◽

Parallel Reactions ◽

Species Specific ◽

Positive Results

AbstractFor the sensitive detection of eggs ofEchinococcus multilocularisin fox faeces by PCR we have evaluated a method based on the previous concentration of helminth eggs by a combination of sequential sieving of faecal samples and flotation of the eggs in zinc chloride solution. The eggs were microscopically detected in the fractions retained in 40 and 20µm mesh sieves. DNA of the taeniid eggs retained in the 20 µm sieve was obtained after alkaline lysis and PCR was performed usingE. multilocularisspecies-specific primers. Compared to the parasitological findings after examination of the small intestines of the foxes, the specificity of the PCR was 100% (no false-positive result with 20 foxes free ofE. multilocularis) and the sensitivity was 94% (33 positive results from total 35 foxes proven to be infected withE. multilocularis). Both false-negative results were obtained with faeces from foxes harbouring immature worms. Using faecal volumes between 2 and 20 ml, no inhibition of PCR was observed as was demonstrated by the amplification of size-modified target in parallel reactions. The tests were undertaken with fresh faeces stored in 70% ethanol, but egg detection by PCR was also possible after inactivation of eggs by freezing the faeces at −80°C for one week or by incubation at +70°C for 2 h.

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Establishment of a Flexible Platform for an Automated Brain-Derived Neurotrophic Factor—ELISA

JALA Journal of the Association for Laboratory Automation ◽

10.1016/j.jala.2007.04.004 ◽

2007 ◽

Vol 12 (4) ◽

pp. 219-229

Author(s):

Ilka Schneider ◽

Paul Stoll ◽

Daniel Haller ◽

Kerstin Thurow

Keyword(s):

Neurotrophic Factor ◽

Brain Derived Neurotrophic Factor ◽

Sample Volume ◽

Test System ◽

Elisa Test ◽

Small Sample ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Automated Processing ◽

High Flexibility

Enzyme-linked immunosorbent assay (ELISA) is a standard immunoassay to estimate protein concentrations in a variety of samples. An automated ELISA procedure was established that allows the measurement of the concentration of numerous proteins in a small sample volume. The automated ELISA procedure was tested by measuring the concentration of brain-derived neurotrophic factor in serum samples from humans. It was shown that the reproducibility of protein concentrations in three assay plates within one automated run was greater than 92%, within independent automated experiments greater than 96%. Automated processing with a maximum capacity of six plates and 240 serum samples per run showed an average interassay precision of 91 %. Serial dilutions of randomly chosen sera displayed significant linearity of recovered concentration. In conclusion it can be stated that the automated assay provides high flexibility with highly reproducible results and has several advantages compared to the manual method, including less operator dependence and faster sample throughput. The investigated ELISA test system seems to exhibit analytical characteristics indicating further clinical application. (JALA 2007;12:219–29)

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ELISA test metapneumoviral infection of bird: methodology of development and use in veterinary practice

Sučasne ptahìvnictvo ◽

10.31548/poultry2021.05-06.024 ◽

2021 ◽

pp. 24-31

Author(s):

O.V. Tsinoviy ◽

◽

L.I. Nalyvayko ◽

Keyword(s):

Test System ◽

Elisa Test ◽

High Price ◽

Enzyme Linked Immunosorbent Assay ◽

Nucleotide Sequencing ◽

Test Systems ◽

Subtype B ◽

Antibody Titers ◽

Scientific Documentation ◽

And Control

In the absence of diagnostic kits for the detection of antibodies to metapneumovirus infection (MPVI) epizootological monitoring in Ukrainian farms is practically not carried out, imported test systems have a "sky-high" price, so there is a need for domestic methods of diagnosing this disease. The most accurate, easy-to-use method is ELISA-based test systems (enzyme-linked immunosorbent assay). A diagnostic ELISA test system for the detection of antibodies to MPVI has been developed and it has been established that this diagnosticum should be used in the practice of veterinary medicine for serological control of metaviral virus infection. The optimal ratios of components for the manufacture of ELISA test system have been worked out. The form of calculation of antibody titers in blood sera of chickens when testing them in one dilution is calculated. The sensitivity and specificity of the ELISA test system were determined (comparative analysis of serum testing results in ELISA, RNGA and RN). Scientific documentation has been developed – instructions for the manufacture and control of ELISA test systems for the detection of antibodies to metapneumovirus infection in the serum of chickens and instructions for its use. Indication and identification of the obtained virus isolate was carried out using polymerase chain reaction (PCR) and nucleotide sequencing. Based on the studies carried out in the suspension of the internal organs of turkeys (trachea, lungs), a virus belonging to subtype B of the genus Metapneumovirus, subfamily Pneumovirinae, family Paramyxoviridae of the order Mononegavirales was revealed. By comparing the nucleotide sequence of the G gene fragment of the PVT-09/B strain with the sequences of strains and isolates of the avian metapneumovirus subtype B published in the GenBank database, it was found that the metapneumovirus isolated from sick turkeys is phylogenetically close to the Brazilian strains 27A-07 2007 and MPV/B/Brazil-07/USP-08 G

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Blocking ELISA to Distinguish Pseudorabies Virus-Infected Pigs from Those Vaccinated with a Glycoprotein gIII Deletion Mutant

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063879000200104 ◽

1990 ◽

Vol 2 (1) ◽

pp. 14-23 ◽

Cited By ~ 10

Author(s):

Saul Kit ◽

Yukikazu Awaya ◽

Haruki Otsuka ◽

Malon Kit

Keyword(s):

Optical Density ◽

Deletion Mutant ◽

Pseudorabies Virus ◽

Standard Dose ◽

False Negative ◽

Elisa Test ◽

Negative Control ◽

Enzyme Linked Immunosorbent Assay ◽

Blocking Elisa ◽

Test Kit

A blocking enzyme-linked immunosorbent assay (ELISA) test has been developed to distinguish pseudorabies virus (PRV)-infected pigs from those immunized with a glycoprotein g92(gIII) deletion mutant, PRV(dlg92dltk). The blocking ELISA utilizes 96-well microtiter test plates coated with a cloned PRV g92(gIII) antigen, a mouse monoclonal antibody against gIII antigen (moMCAgIII): horseradish peroxidase (HRPO) conjugate, and undiluted test sera. Analyses can be completed in less than 3 hours with results printed out by an automated plate reader. Analyses on over 300 pig sera from PRV-free farms, on sera from other species, and on control sera containing antibodies to microorganisms other than PRV showed that the ratio of the optical density at 405 nm for the test sample to the optical density at 405 nm for the negative control (S/N value) was >0.7 for all sera. No false positives were identified. Likewise, the S/N values were >0.7 for over 400 sera obtained from pigs vaccinated twice with more than 1,000 times the standard PRV (dlg92dltk) dose or 1–4 times with the standard dose (2 × 105 TCID50/pig). Following challenge exposure to virulent PRV, the S/N values of the vaccinates were 0.1, showing that g92(gIII) antibodies in the sera of experimentally challenged pigs strongly blocked the binding of the moMCAgIII: HRPO conjugate to the antigen-coated wells. Sera of 233 pigs from PRV-infected herds with virus neutralization (VN) titers of 1:4 or greater were tested. All except 2 of these sera had S/N values <0.7 and more than 175 had S/N values <0.1. Sixteen sera from feral pigs with VN titers of 1:4 or greater had S/N values of 0.24 or less, but 2 sera with VN titers of 1:4 when tested 5 years prior to the PRV g92(gIII) blocking ELISA test gave false negative S/N values. Twenty-four of 29 pig sera from PRV-infected herds with VN titers < 1:4 were positive for g92(gIII) antibodies, illustrating the sensitivity of the PRV g92(gIII) blocking ELISA test. Analyses on 7 sera with VN titers of 1:4–1:64 showed that titers obtained with the PRV g92(gIII) blocking ELISA test were from 2- to 16-fold greater than the VN titers. The accuracy and sensitivity of the PRV g92(gIII) blocking ELISA test was further demonstrated by analyses of 40 unknown sera supplied in the National Veterinary Services Laboratories 1988 PRV check test kit.

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