COMPARISON OF PERFORMANCE CHARACTERISTICS BETWEEN LATERAL FLOW, ELISAAND ELECTROCHEMILUMINESCENCE IMMUNOASSAYS FOR THE DETECTION OF SARS-COV-2 ANTIBODIES AMONG HEALTHCARE WORKERS

Background: The detection of SARS-CoV-2 IgG is important to determine the course of COVID-19. Medical professionals and researchers have been urging the need for wide and rapid testing of citizens in order to plan measures that can contain the spread of the virus. Antibody tests play an important role throughout the patient care pathway and are vital for the management and surveillance of the virus. Although RTPCR is considered to be the gold standard, serological tests based on antibodies could be very helpful for on-time detection. We performed one to one assessment of electrochemiluminescence immunoassay, enzyme immunoassay (EIAs), and point-of-care lateral ow assay (POCTs) to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibody. Materials and Methods: 611 healthcare workers were recruited between November and December 2020 at Central Research Laboratory, KIMS. ® Collected serum samples were analysed using three commercially available assays: the Elecsys , Anti-SARS CoV-2 Human IgG ELISA, the Standard Q IgG/IgM combo assay following the manufacturer's protocol to measure the IgG titer of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Results:The kits displayed a sensitivity of 91.8%, 79.5% ,61.2% and a specicity of 80.2%, 64.1% ,61.7% in order. Conclusion: ® Our results indicate a high sensitivity and specicity for the Elecsys assay compared to Anti-SARS CoV-2 Human IgG ELISA, the Standard Q IgG/IgM combo assays.

Download Full-text

COMPARISON OF PERFORMANCE CHARACTERISTICS BETWEEN LATERAL FLOW, ELISA AND ELECTROCHEMILUMINESCENCE IMMUNOASSAYS FOR THE DETECTION OF SARS-COV-2 ANTIBODIES AMONG HEALTHCARE WORKERS

10.1101/2021.04.29.21256260 ◽

2021 ◽

Author(s):

M R Shincy ◽

Vandana Govindan ◽

H H Sudhakar ◽

V T Venkatesha ◽

K Padmapriya ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Healthcare Workers ◽

Care Pathway ◽

Point Of Care ◽

Lateral Flow ◽

Central Research ◽

Serum Samples ◽

Igg Antibody ◽

Human Igg ◽

Serological Tests

ABSTRACTBackgroundMedical professionals and researchers have been urging the need for wide and rapid testing of citizens in order to plan measures that can contain the spread of the virus. Antibody tests play an important role throughout the patient care pathway and are vital for the management and surveillance of the virus. Although RT-PCR is considered as the gold standard, serological tests based on antibodies are helpful for on-time detection. We performed one to one assessment of point-of-care lateral flow assay (POCTs), enzyme immunoassay (EIAs), electrochemiluminescence immunoassay (CLIA), to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibody.Materials and Methods611 healthcare workers were recruited between November and December 2020 at Central Research Laboratory, KIMS. Collected serum samples were analysed according to manufacturer’s protocol. The Standard Q IgG/IgM combo assay, Anti-SARS CoV-2 Human IgG ELISA, and the Elecsys® to measure the IgG titer of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).ResultsThe kits displayed a sensitivity of 61.2%,79.5%, 91.8% and specificity of 61.7%,64.1%,80.2% for the Standard Q IgG/IgM combo assay, Anti-SARS CoV-2 Human IgG ELISA, and the Elecsys® in order.ConclusionOur results indicate high sensitivity and specificity for the Elecsys® assay compared to Anti-SARS CoV-2 Human IgG ELISA, the Standard Q IgG/IgM combo assay.

Download Full-text

Comparative analysis of three point-of-care lateral flow immunoassays for detection of anti-SARS-CoV-2 antibodies in COVID-19 confirmed healthcare workers

10.1101/2020.11.11.20229914 ◽

2020 ◽

Author(s):

Danielle Dias Conte ◽

Joseane Mayara Almeida Carvalho ◽

Luciano Kleber de Souza Luna ◽

Klinger Soares Faíco-Filho ◽

Ana Helena Perosa ◽

...

Keyword(s):

Healthcare Workers ◽

Large Scale ◽

Point Of Care ◽

Antibody Test ◽

Cost Effective ◽

Lateral Flow ◽

Rt Pcr ◽

Serum Samples ◽

Igg Antibody ◽

Serological Tests

AbstractSince the Coronavirus Disease 2019 (COVID-19) pandemic, Brazil has the third-highest number of confirmed cases and the second-highest number of recovered patients. SARS-CoV-2 detection by real-time RT-PCR is the gold standard in certified infrastructured laboratories. However, for large-scale testing, diagnostics should be fast, cost-effective, widely available, and deployed for the community, such as serological tests based on lateral flow immunoassay (LFIA) for IgM/IgG detection. We evaluated three different commercial point-of-care (POC) LFIAs for anti-SARS-CoV-2 IgM and IgG detection in capillary whole blood of 100 healthcare workers (HCW) previously tested by RT-PCR: 1) COVID-19 IgG/IgM BIO (Bioclin, Brazil), 2) Diagnostic kit for IgM/IgG Antibody to Coronavirus (SARS-CoV-2) (Livzon, China); and 3) SARS-CoV-2 Antibody Test (Wondfo, China). A total of 84 positives and 16 negatives HCW were tested. The data was also analyzed by the number of days post symptoms (DPS) in three groups: <30 (n=26), 30-59 (n=42), and >59 (n=16). Overall detection was 85.71%, 47.62%, and 44.05% for Bioclin, Livzon, and Wondfo, respectively, with a specificity of 100%, and 98.75% for Livzon on storage serum samples. Bioclin was more sensitive (p<0.01), regardless of the DPS. Thus, the Bioclin can be used as a POC test to monitor SARS-CoV-2 seroconversion in HCW.

Download Full-text

COVID-19 Seroprevalence among Healthcare Workers of a Large COVID-19 Hospital in Rome Reveals Strengths and Limits of Two Different Serological Tests

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18052650 ◽

2021 ◽

Vol 18 (5) ◽

pp. 2650

Author(s):

Giuseppe Vetrugno ◽

Daniele Ignazio La Milia ◽

Floriana D’Ambrosio ◽

Marcello Di Pumpo ◽

Roberta Pastorino ◽

...

Keyword(s):

Blood Test ◽

Healthcare Workers ◽

Point Of Care ◽

Venous Blood ◽

Administrative Staff ◽

Serological Tests ◽

Predictive Values ◽

Work From Home ◽

Significant Difference ◽

Sensitivity Specificity

Healthcare workers are at the forefront against COVID-19, worldwide. Since Fondazione Policlinico Universitario A. Gemelli (FPG) IRCCS was enlisted as a COVID-19 hospital, the healthcare workers deployed to COVID-19 wards were separated from those with limited/no exposure, whereas the administrative staff were designated to work from home. Between 4 June and 3 July 2020, an investigation was conducted to evaluate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin (IgG) antibodies among the employees of the FPG using point-of-care (POC) and venous blood tests. Sensitivity, specificity, and predictive values were determined with reverse-transcription polymerase chain reaction on nasal/oropharyngeal swabs as the diagnostic gold standard. The participants enrolled amounted to 4777. Seroprevalence was 3.66% using the POC test and 1.19% using the venous blood test, with a significant difference (p < 0.05). The POC test sensitivity and specificity were, respectively, 63.64% (95% confidence interval (CI): 62.20% to 65.04%) and 96.64% (95% CI: 96.05% to 97.13%), while those of the venous blood test were, respectively, 78.79% (95% CI: 77.58% to 79.94%) and 99.36% (95% CI: 99.07% to 99.55%). Among the low-risk populations, the POC test’s predictive values were 58.33% (positive) and 98.23% (negative), whereas those of the venous blood test were 92.86% (positive) and 98.53% (negative). According to our study, these serological tests cannot be a valid alternative to diagnose COVID-19 infection in progress.

Download Full-text

Point-of-care high-sensitivity assay on PATHFAST as the backup in the emergency room

Medicine Access Point of Care ◽

10.1177/23992026211055095 ◽

2021 ◽

Vol 5 ◽

pp. 239920262110550

Author(s):

Joško Osredkar ◽

Katja Krivic ◽

Teja Fabjan ◽

Kristina Kumer ◽

Jure Tršan ◽

...

Keyword(s):

Blood Serum ◽

Troponin I ◽

Point Of Care ◽

High Sensitivity ◽

Turnaround Time ◽

Serum Samples ◽

Linear Relationships ◽

Accuracy And Precision ◽

Laboratory Results ◽

Key Indicators

Aim: Although the levels of cardiac troponin I (cTnI) have proved to be a useful diagnostic biomarker of acute myocardial infarction, there are a wide variety of point-of-care (POC) analysers, which provide measurements of cTnI. The aim of this study was to compare the results obtained by the ADVIA Centaur ultra-assay cTnI assay (us-cTnI), ADVIA Centaur high-sensitive cTnI assay (hs-cTnI) and a POC high-sensitivity assay using PATHFAST. We also aimed to explore total turnaround time (TAT) for laboratory results using the POC PATHFAST analyser. Methods: Samples from 161 patients were taken. Of these samples, 129 were tested with all three assays (us-cTnI, hs-cTnI and PATHFAST), and 32 samples were tested on PATHFAST for the comparison of whole blood, serum and plasma. Results: Comparison of the POC testing methods in this study demonstrated that there are strong linear relationships between all three cTnI assays (us-cTnI, hs-cTnI and POC on PATHFAST). Furthermore, we also show there are strong linear relationships between the two high-sensitive cTnI assays (hs-cTnI and PATHFAST) for blood serum samples, as determined by Passing–Bablok regression analyses. In our comparison of our new data with our older study, the TAT went down. Conclusion: The timeliness of laboratory results is, in addition to accuracy and precision, one of the key indicators of laboratory performance, and at the same time has a significant impact on the course of the patient’s condition. It is therefore important that the laboratory strives to meet the expectations of clinicians regarding the time from the order to the result of the analysis.

Download Full-text

Comparison of Coombs Gel Test with ELISA and Standard Tube Agglutination Tests Used in Serological Diagnosis of Brucellosis

Infectious Diseases and Clinical Microbiology ◽

10.36519/idcm.2019.0024 ◽

2020 ◽

Vol 2 (1) ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Cigdem Akalan Kuyumcu ◽

Serpil Erol ◽

Rıza Adaleti ◽

Seniha Senbayrak ◽

Secil Deniz ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Diagnostic Tests ◽

Serological Test ◽

High Sensitivity ◽

Serological Diagnosis ◽

Control Groups ◽

Serum Samples ◽

Serological Tests ◽

Reliable Test ◽

And Control

Objective: Serological tests are the most commonly used tests in the diagnosis of brucellosis; however, each serological test has some drawbacks. In this study, we aimed to determine the value of the Brucella Coombs gel test (BCGT) in the serological diagnosis of brucellosis in comparison with Standard tube agglutination (STA) and ELISA tests. Materials and Methods: The study included 42 patients who were considered to have brucellosis as a preliminary diagnosis. BCGT, Brucella-IgM/IgG ELISA, and STA tests were performed from serum samples of the patients. The correlation of the diagnostic tests was analyzed using Cohen’s Kappa Analysis. Results: Twenty-seven (64.2%) of 42 patients were diagnosed with brucellosis according to their medical history and clinical and serological tests. The sensitivity and specificity of BCGT to diagnose brucellosis was 96.2%, and 100%, respectively. The sensitivity and specificity for the diagnosis of brucellosis 62.9% and 100% for STA, respectively; 33.3% and 66.6% for Brucella-IgM; and 66.6% and 100% for Brucella-IgG. BCGT was significantly correlated with STA (κ= 0.590) and Brucella-IgG (κ=0.539) Conclusion: BCGT can be utilized as a simple and reliable test in the diagnosis of brucellosis with high sensitivity and specificity. Nevertheless, the sensitivity and specificity of BCGT should be demonstrated by comprehensive studies, including culture-confirmed cases and control groups.

Download Full-text

Longitudinal Change of Severe Acute Respiratory Syndrome Coronavirus 2 Antibodies in Patients with Coronavirus Disease 2019

The Journal of Infectious Diseases ◽

10.1093/infdis/jiaa229 ◽

2020 ◽

Vol 222 (2) ◽

pp. 183-188 ◽

Cited By ~ 38

Author(s):

Guoxin Zhang ◽

Shuke Nie ◽

Zhaohui Zhang ◽

Zhentao Zhang

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Disease Onset ◽

Immunoglobulin M ◽

Longitudinal Change ◽

Igg Antibody ◽

Serological Tests ◽

Significant Difference ◽

Rapid Spread ◽

Novel Coronavirus ◽

Acid Test

Abstract Background A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has recently emerged and caused the rapid spread of coronavirus disease 2019 (COVID-19) worldwide. Methods We did a retrospective study and included COVID-19 patients admitted to Renmin Hospital of Wuhan University between 1 February and 29 February 2020. Antibody assay was conducted to detect COVID-19 envelope protein E and nucleocapsid protein N antigen. Results One hundred twelve patients were recruited with symptoms of fever, cough, fatigue, myalgia, and diarrhea. All patients underwent antibody tests. Fifty-eight (51.79%) were positive for both immunoglobulin M (IgM) and immunoglobulin G (IgG), 7 (6.25%) were negative for both antibodies, 1 (0.89%) was positive for only IgM, and 46 (41.07%) were positive for only IgG. IgM antibody appeared within a week post–disease onset, lasted for 1 month, and gradually decreased, whereas IgG antibody was produced 10 days after infection and lasted for a longer time. However, no significant difference in levels of IgM and IgG antibodies between positive and negative patients of nucleic acid test after treatment was found. Conclusions Our results indicate that serological tests could be a powerful approach for the early diagnosis of COVID-19.

Download Full-text

Quantitative SARS-CoV-2 Antibody Screening of Healthcare Workers in the Southern Part of Kyoto City During the COVID-19 Pre-pandemic Period

Frontiers in Public Health ◽

10.3389/fpubh.2020.595348 ◽

2020 ◽

Vol 8 ◽

Cited By ~ 1

Author(s):

Kohei Fujita ◽

Shinpei Kada ◽

Osamu Kanai ◽

Hiroaki Hata ◽

Takao Odagaki ◽

...

Keyword(s):

Healthcare Workers ◽

Early Stage ◽

Case Fatality ◽

Serum Samples ◽

Igg Antibody ◽

Kyoto City ◽

History Of ◽

Heavy Burden ◽

Antibody Levels ◽

Mental And Physical Health

Background: The coronavirus disease-2019 (COVID-19) pandemic is associated with a heavy burden on the mental and physical health of patients, regional healthcare resources, and global economic activity. While understanding of the incidence and case-fatality rates has increased, there are limited data concerning seroprevalence of antibodies against the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) in healthcare workers during the pre-pandemic period. This study aimed to quantitatively evaluate seroprevalence of SARS-CoV-2 antibodies in healthcare workers in the southern part of Kyoto city, Japan.Methods: We prospectively recruited healthcare workers from a single hospital between April 10 and April 20, 2020. We collected serum samples from these participants and quantitatively evaluated SARS-CoV-2 IgG antibody levels using enzyme-linked immunosorbent assays.Results: Five (5.4%), 15 (16.3%), and 72 (78.3%) participants showed positive, borderline, and negative serum SARS-CoV-2 IgG antibody status, respectively. We found the mean titer associated with each antibody status (overall, positive, borderline, and negative) was clearly differentiated. Participants working at the otolaryngology department and/or with a history of seasonal common cold symptoms had a significantly higher SARS-CoV-2 IgG antibody titer (p = 0.046, p = 0.046, respectively).Conclusions: Five (5.4%) and 15 (16.3%) participants tested positive and borderline, respectively, for SARS-CoV-2 IgG antibody during the COVID-19 pre-pandemic period. These rates were higher than expected, based on government situation reports. These findings suggest that COVID-19 had already spread within the southern part of Kyoto city at the early stage of the pandemic.

Download Full-text

Diagnostic-test evaluation of immunoassays for anti-Toxoplasma gondii IgG antibodies in a random sample of Mexican population

The Journal of Infection in Developing Countries ◽

10.3855/jidc.3858 ◽

2014 ◽

Vol 8 (05) ◽

pp. 642-647 ◽

Cited By ~ 7

Author(s):

Heriberto Caballero-Ortega ◽

Rocío Castillo-Cruz ◽

Sandra Murieta ◽

Luz Belinda Ortíz-Alegría ◽

Esther Calderón-Segura ◽

...

Keyword(s):

Toxoplasma Gondii ◽

Western Blot ◽

Latin American ◽

High Sensitivity ◽

Reference Standards ◽

Igg Antibodies ◽

Serum Samples ◽

Serological Tests ◽

Western Blots ◽

Open Population

Introduction: There are few articles on evaluation of Toxoplasma gondii serological tests. Besides, commercially available tests are not always useful and are expensive for studies in open population. The aim of this study was to evaluate in-house ELISA and western blot for IgG antibodies in a representative sample of people living in Mexico. Methodology: Three hundred and five serum samples were randomly selected from two national seroepidemiological survey banks; they were taken from men and women of all ages and from all areas of the country. ELISA cut-off was established using the mean plus three standard deviations of negative samples. Western blots were analysed by two experienced technicians and positivity was established according to the presence of at least three diagnostic bands. A commercial ELISA kit was used as a third test. Two reference standards were built up: one using concordant results of two assays leaving the evaluated test out and the other in which the evaluated test was included (IN) with at least two concordant results to define diagnosis. Results: the lowest values of diagnostic parameters were obtained with the OUT reference standards: in-house ELISA had 96.9% sensitivity, 62.1% specificity, 49.6% PPV, 98.1% NPV and 71.8% accuracy, while western blot presented 81.8%, 89.7%, 84.0%, 88.2% and 86.6% values and the best kappa coefficient (0.72-0.82). Conclusions: The in-house ELISA is useful for screening people of Mexico, due to its high sensitivity, while western blot may be used to confirm diagnosis. These techniques might prove useful in other Latin American countries.

Download Full-text

Serological Diagnosis of Brucella Infections in Odontocetes

Clinical and Vaccine Immunology ◽

10.1128/cvi.00413-08 ◽

2009 ◽

Vol 16 (6) ◽

pp. 906-915 ◽

Cited By ~ 11

Author(s):

Gabriela Hernández-Mora ◽

Charles A. Manire ◽

Rocío González-Barrientos ◽

Elías Barquero-Calvo ◽

Caterina Guzmán-Verri ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Brucella Melitensis ◽

Enzyme Linked Immunosorbent Assay ◽

Dot Blot ◽

Serum Samples ◽

Igg Antibody ◽

Serological Tests ◽

Diagnostic Potential ◽

Control Serum ◽

History Of

ABSTRACT Brucella ceti causes disease in Odontoceti. The absence of control serum collections and the diversity of cetaceans have hampered the standardization of serological tests for the diagnosis of cetacean brucellosis. Without a “gold” standard for sensitivity and specificity determination, an alternative approach was followed. We designed an indirect enzyme-linked immunosorbent assay (iELISA) that recognizes immunoglobulins G (IgGs) from 17 odontocete species as a single group. For the standardization, we used Brucella melitensis and Brucella abortus lipopolysaccharides, serum samples from seven resident odontocetes with no history of infectious disease displaying negative rose bengal test (RBT) reactions, and serum samples from seven dolphins infected with B. ceti. We compared the performance of the iELISA with those of the protein G ELISA (gELISA), the competitive ELISA (cELISA), and the immunofluorescence (IF) and dot blot (DB) tests, using 179 odontocete serum samples and RBT as the reference. The diagnostic potential based on sensitivity and specificity of the iELISA was superior to that of gELISA and cELISA. The correlation and agreement between the iELISA and the gELISA were relatively good (R i/g 2 = 0.65 and κi/g = 0.66, respectively), while the correlation and agreement of these two ELISAs with cELISA were low (R i/c 2 = 0.46, R g/c 2 = 0.37 and κi/c = 0.62, κg/c = 0.42). In spite of using the same anti-odontocete IgG antibody, the iELISA was more specific than were the IF and DB tests. An association between high antibody titers and the presence of neurological symptoms in dolphins was observed. The prediction is that iELISA based on broadly cross-reacting anti-dolphin IgG antibody would be a reliable test for the diagnosis of brucellosis in odontocetes, including families not covered in this study.

Download Full-text

Next-generation sequencing combined with serological tests based pathogen analysis for a neurocysticercosis patient with a 20-year history:a case report

BMC Neurology ◽

10.1186/s12883-021-02277-7 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Bin Chen ◽

Zheng Chen ◽

Yi-shu Yang ◽

Gui-lan Cai ◽

Xiao-jiao Xu ◽

...

Keyword(s):

Next Generation Sequencing ◽

Taenia Solium ◽

Clinical Manifestations ◽

Next Generation ◽

Serum Samples ◽

Igg Antibody ◽

Serological Tests ◽

Diagnostic Efficacy ◽

Variable Sensitivity ◽

Generation Sequencing

Abstract Background Neurocysticercosis (NCC) is the most common helminthic infection of the central nervous system (CNS) caused by the larval stage of Taenia solium. Accurate and early diagnosis of NCC remains challenging due to its heterogeneous clinical manifestations, neuroimaging deficits, variable sensitivity, and specificity of serological tests. Next-generation sequencing (NGS)-based pathogen analysis in patient’s cerebrospinal fluid (CSF) with NCC infection has recently been reported indicating its diagnostic efficacy. In this case study, we report the diagnosis of a NCC patient with a symptomatic history of over 20 years using NGS analysis and further confirmation of the pathology by immunological tests. Case presentation This study reports the clinical imaging and immunological features of a patient with a recurrent headache for more than 20 years, which worsened gradually with the symptom of fever for more than 7 years and paroxysmal amaurosis for more than 1 year. By utilizing NGS technique, the pathogen was detected in patient’s CSF, and the presence of Taenia solium-DNA was confirmed by a positive immunological reaction to cysticercus IgG antibody in CSF and serum samples. The symptoms of the patient were alleviated, and the CSF condition was improved substantially after the anti-helminthic treatment. Conclusions This study suggests that combining CSF NGS with cysticercus IgG testing may be a highly promising approach for diagnosing the challenging cases of NCC. Further studies are needed to evaluate the parasitic DNA load in patients’ CSF for the diagnosis of disease severity, stage, and monitoring of therapeutic responses.

Download Full-text