scholarly journals Evaluating ELISA, Immunofluorescence, and Lateral Flow Assay for SARS-CoV-2 Serologic Assays

2020 ◽  
Vol 11 ◽  
Author(s):  
Moïse Michel ◽  
Amar Bouam ◽  
Sophie Edouard ◽  
Florence Fenollar ◽  
Fabrizio Di Pinto ◽  
...  

BackgroundThe SARS-CoV-2 outbreak has emerged at the end of 2019. Aside from the detection of viral genome with specific RT-PCR, there is a growing need for reliable determination of the serological status. We aimed at evaluating five SARS-CoV-2 serology assays.MethodsAn in-house immunofluorescence assay (IFA), two ELISA kits (EUROIMMUN® ELISA SARS-CoV-2 IgG and NovaLisa® SARS-CoV-2 IgG and IgM) and two lateral flow assays (T-Tek® SARS-CoV-2 IgG/IgM Antibody Test Kit and Sure Bio-tech® SARS-CoV-2 IgM/IgG Antibody Rapid Test) were compared on 40 serums from RT-PCR-confirmed SARS-CoV-2 infected patients and 10 SARS-CoV-2 RT-PCR negative subjects as controls.ResultsControl subjects tested negative for SARS-CoV-2 antibodies with all five systems. Estimated sensitivities varied from 35.5 to 71.0% for IgG detection and from 19.4 to 64.5% for IgM detection. For IgG, in-house IFA, EuroImmun, T-Tek and NovaLisa displayed 50–72.5% agreement with other systems except IFA vs EuroImmun and T-Tek vs NovaLisa. Intermethod agreement for IgM determination was between 30 and 72.5%.DiscussionThe overall intermethod agreement was moderate. This inconsistency could be explained by the diversity of assay methods, antigens used and immunoglobulin isotype tested. Estimated sensitivities were low, highlighting the limited value of antibody detection in CoVID-19.ConclusionComparison of five systems for SARS-CoV-2 IgG and IgM antibodies showed limited sensitivity and overall concordance. The place and indications of serological status assessment with currently available tools in the CoVID-19 pandemic need further evaluations.

2021 ◽  
pp. 60-62
Author(s):  
Tagajdid Mohamed Rida ◽  
Konzi Clémence ◽  
El Kochri Safae ◽  
Elannaz Hicham ◽  
Abi Rachid ◽  
...  

Introduction: Currently, polymerase chain reaction (PCR) based viral RNAdetection is the standard for COVID-19 diagnosis [2]. Though, RNA testing based on throat or nasopharyngeal swabs has shown a number of false-negative results. Antibody detection tests have been developed to detect specic antibodies, IgM and IgG, to SRAS-CoV-2 virus. The clinical relevance of these tests is still under evaluation and is highly related to their clinical performance. Our objective is to assess analytical performances of nine SARS-CoV-2 antibodies immunoassays. Materiel and Method: We collected 80 blood samples from PCR-conrmed COVID-19 patients diagnosed in our Virology department (20 samples collected at day 10 after the onset of symptoms, 60 collected after day 14 following the onset of symptoms) and 20 blood samples from patients SARS-CoV-2 RT-PCR negative. All sera were tested with nine SARS-CoV-2 antibodies immunoassays ARCHITECT SARS-CoV-2 IgG® (Abbott), COVID-19 VIRCLIA® IgG MONOTEST (Vircell), COVID-19 VIRCLIA® IgM+IgA MONOTEST (Vircell), COVID-19 ELISA IgG® (Vircell), COVID-19 ELISA IgM+IgA® (Vircell), Elecsys® Anti-SARS-CoV-2 (Roche), FREND® COVID-19 IgG/IgM Duo (NanoEntek), COVID-PRESTO® (AAZ) and COVID-19 (SARS-CoV-2) IgM/IgG Antibody Test Kit® (Labnovation Technologies). Results: Sensitivity of tests increases once the seroconversion to anti-SARS-CoV-2 IgG positive in most individuals occurs toward the end of week 2 post-infection. COVID-19 PRESTO had the best accuracy in our study showing 100% sensitivity after day 14 following the onset of symptoms. All of the tests had a specicity of 100%. Conclusion: Serological tests are sensitive for the latest stages of COVID-19 infection. Recommendations on using SRAS-COV-2 antibody detection tests are continuously improving based on current knowledge of host antibody responses during infection. They are of great value in cases presenting COVID-19 symptoms with negative RT-PCR.


Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1441
Author(s):  
Suelen Basgalupp ◽  
Giovana dos Santos ◽  
Marina Bessel ◽  
Lara Garcia ◽  
Ana Carolina de Moura ◽  
...  

Serological assays emerged as complementary tools to RT-PCR in the diagnosis of SARS-CoV-2 as well as being needed for epidemiological studies. This study aimed to assess the performance of a rapid test (RT) compared to that of serological tests using finger prick blood samples. A total of 183 samples were evaluated, 88 of which were collected from individuals with negative RT-PCR and 95 from positive RT-PCR individuals. The diagnostic performance of RT (WONDFO®) and LUMIT (PROMEGA®) were compared to that of ELISA (EUROIMMUN®) for detecting antibodies against SARS-CoV-2 according to time from symptoms onset. The IgG antibody tests were detected in 77.4% (LUMIT), 77.9% (RT), and 80.0% (ELISA) of individuals. The detection of antibodies against SARS-CoV-2 increases in accordance with increasing time from symptoms onset. Considering only time from symptoms onset >21 days, the positivity rate ranged from 81.8 to 97.0% between the three tests. The RT and LUMIT showed high agreement with ELISA (agreement = 91.5%, k = 0.83, and agreement = 96.3%, k = 0.9, respectively) in individuals who had symptoms 15 to 21 days before sample collection. Compared to that of the ELISA assay, our results show sensitivity ranged from 95% to 100% for IgG antibody detection in individuals with symptoms onset between 15 and 21 days before sample collection. The specificity was 100% in individuals with symptoms onset >15 days before serological tests. This study shows good performance and high level of agreement of three immunoassays for the detection of SARS-CoV-2 antibodies.


Author(s):  
Jesha Mundodan ◽  
Samina Hasnain ◽  
Hayat Khogali ◽  
Soha Shawqi Al Bayat ◽  
Dina Ali ◽  
...  

Background: In response to the growing coronavirus disease 2019 (COVID-19) pandemic and the shortage of laboratory based molecular testing capacity and reagents, multiple diagnostic test manufacturers have developed rapid and easy to use devices to facilitate testing outside laboratory settings. These kits are either based on detection of proteins from SARS-CoV-2 virus or detection of antigen or human antibodies generated in response to the infection. However, it is important to understand their performance characteristics and they must be validated in the local population setting.Design and Methods: The objective is to assess the validity of the rapid test for IgG and IgM immunoglobulins compared to the current gold standard reverse transcription polymerase chain reaction (RT-PCR) test. A total of 16951 asymptomatic individuals were tested by the Ministry of Public Health track-and-trace team using both rapid immunodiagnostic test and RT-PCR as part of screening across various random settings with potential risk of community interaction prior to gradual lifting of restrictions in Qatar.  Rapid test was considered to be posiive if both IgG and IgM are positive, while only IgG/IgM positive was considered as rapid test negative. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated.Results: The sensitivity of rapid test kit was found to be 0.9%, whereas the specificity was found to be 97.8%. the PPV was found to be 0.3% whereas the NPV was found to be 99.4%.Conclusion: Based on the outcome and results of the study, it appears that the sensitivity and PPV of the rapid antibody test are low. As such, this test is not recommended for use to assist in taking clinic-based decisions or decisions related to quarantine/isolation.


2020 ◽  
Author(s):  
Danielle Dias Conte ◽  
Joseane Mayara Almeida Carvalho ◽  
Luciano Kleber de Souza Luna ◽  
Klinger Soares Faíco-Filho ◽  
Ana Helena Perosa ◽  
...  

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.


2021 ◽  
Vol 13 (4) ◽  
pp. 910-916
Author(s):  
Theodore Heyming ◽  
Kellie Bacon ◽  
Bryan Lara ◽  
Chloe Knudsen-Robbins ◽  
Aprille Tongol ◽  
...  

The primary aim of this study was to determine the seroprevalence of SARS-CoV-2 antibodies in a population of pediatric healthcare workers (HCWs). This study was conducted 14 May–13 July 2020. Study participants included pediatric HCWs at a pediatric hospital with either direct patient contact or close proximity to patient-care areas. SARS-CoV-2 antibodies were assessed via the Wytcote Superbio SARS-CoV-2 IgM/IgG Antibody Fast Detection Kit and the Abbott Architect SARS-CoV-2 IgG assay. Participants underwent RT-PCR testing upon entry to the study and following rapid IgM+/IgG+ results; respiratory panel PCR (RP-PCR) was performed following IgM+ results. A total of 57 of 289 (19.7%) of participants demonstrated positive serology as assessed by the Wytcote rapid kit (12 on Day 1 and 45 throughout the study). However, only one of these participants demonstrated IgG+ serology via the Abbott assay. Two participants tested SARS-CoV-2+ via RT-PCR testing. One individual was adenovirus+ and enterovirus/rhinovirus+. In our study population, we observed a seroprevalence of SARS-CoV-2 antibodies of 0.35%. The lack of concordance between antibody tests suggests that the Wytcote rapid test kit may not be of use as a screening tool. However, the feasibility of the overall process indicates that a similar methodology may have potential for future epidemiologic surveillance.


2021 ◽  
Author(s):  
Dingying Shan ◽  
Jessica Hsiung ◽  
Kevin P. Bliden ◽  
Su Zhao ◽  
Tao Liao ◽  
...  

Sensitive detection of IgG antibodies against SARS-CoV-2 is important to assessing immune responses to viral infection or vaccination and immunity duration. Antibody assays using non-invasive body fluids such as saliva could facilitate mass testing including young children, elderly and those who resist blood draws, and easily allowing longitudinal testing/monitoring of antibodies over time. Here, we developed a new lateral flow (nLF) assay that sensitively detects SARS-CoV-2 IgG antibodies in the saliva samples of vaccinated individuals and previous COVID-19 patients. The 25-minute nLF assay detected anti-spike protein (anti-S1) IgG in saliva samples with 100% specificity and high sensitivity from both vaccinated (99.51% for samples ≥ 19 days post 1st Pfizer/BioNTech or Moderna mRNA vaccine dose) and infected individuals. Antibodies against nucleocapsid protein (anti-NCP) was detected only in the saliva samples of COVID-19 patients and not in vaccinated samples, allowing facile differentiation of vaccination from infection. SARS-CoV-2 anti-S1 IgG antibody in saliva measured by nLF demonstrated similar evolution trends post vaccination to that in matching dried blood spot (DBS) samples measured by a quantitative pGOLD lab-test, enabling the nLF to be a valid tool for non-invasive personalized monitoring of SARS-CoV-2 antibody persistence. The new salivary rapid test platform can be applied for non-invasive detection of antibodies against infection and vaccination in a wide range of diseases.


Author(s):  
Rui Liu ◽  
Xinghui Liu ◽  
Huan Han ◽  
Muhammad Adnan Shereen ◽  
Zhili Niu ◽  
...  

AbstractBackgroundAs the increasing number of Corona Virus Disease 2019 (COVID-19) patients caused by the severe acute respiratory coronavirus 2 (SARS-CoV-2), which caused an outbreak initiated from Wuhan, China in December, 2019, the clinical features and treatment of COVID-19 patients have been understood. However, it is urgent to need the rapid and accurate detection for SARS-CoV-2 infection diagnosis. We aimed to evaluate the antibodies-based and nucleic acid-based tests (NAT) for SARS-CoV-2-infected patients.MethodWe retrospectively and observationally studied 133 patients diagnosed with SARS-CoV-2 and admitted in Renmin Hospital of Wuhan University, China, from Feb 17 to Mar 1, 2020. Demographic data, symptoms, clinical examination, laboratory tests, and clinical outcomes were collected. Data were compared between IgM-IgG antibody test and real-time RT-PCR detection for COVID-19 patients.ResultsOf 133 patients with SARS-CoV-2 infection, there were 44 moderate cases, 52 severe cases, and 37 critical cases with no significant difference of gender and age among three subgroups. Overall, the positive ratio in IgM antibody test was higher than in RT-PCR detection. In RT-PCR detection, the positive ratio was 65.91%, 71.15%, and 67.57% in moderate, severe, and critical cases, respectively. Whereas, the positive ratio of IgM/IgG antibody detection in patients was 79.55%/93.18%, 82.69%/100%, and 72.97%/97.30% in moderate, severe, and critical cases, respectively. Moreover, the concentrations of antibodies were also measured in three subgroups.ConclusionThe IgM-IgG antibodies-based test exhibited a comparative superiority to the NAT for COVID-19 diagnosis, which provides an effective complement to the false negative results from NAT for SARS-CoV-2 infection diagnosis.


Author(s):  
Ranti Permatasari ◽  
Aryati Aryati ◽  
Budi Arifah

Hepatitis C (HCV) infection could be spread by blood transfusion. Screening of HCV in donor blood could prevent HCV infection to the recipient. HCV antibody test using rapid test of multiple antibody detection by immunochromatography method is an easy and rapid test that could detect four HCV antibodies separately. The aim of this study was to evaluate the diagnostic value of antibody HCV using multiple antibody detection rapid test in diagnosing HCV infection. This was an analytical observational study with a cross sectional design. The samples consisted of 42 donors’ blood serum from the Surabaya Branch of the Indonesian Red Cross which underwent HCV infection test using ELISA method. The samples were then tested using PCR HCV RNA as the gold standard and antibody HCV multiple antibodydetection rapid test The diagnostic value of HCV antibody test using multiple antibody detection rapid test by immunochromatography method showed a diagnostic sensitivity of 100%, diagnostic specificity of 75%, positive predictive value of 66.7% and negative predictive value of 100%, a diagnostic efficiency of 83.3%, with a positive probability ratio of 4 times. The most often positive antibody pattern was four (4) positive antibodies (core protein, NS3, NS4 and NS5). Core protein (CP) and NS3 were the most often positive antibodies. Based on this study result, the HCV antibody test using multiple antibody detection rapid test by immunochromatography method has a good diagnostic value.


VirusDisease ◽  
2021 ◽  
Author(s):  
Vani Maya ◽  
Jyothi Embekkat Kaviyil ◽  
Dinoop Koral Ponnambath ◽  
Renjith P. Nair ◽  
Anugya Bhatt ◽  
...  

2017 ◽  
Vol 33 (1) ◽  
pp. 8-15
Author(s):  
LR Barman ◽  
RD Sarker ◽  
BC Das ◽  
EH Chowdhury ◽  
PM Das ◽  
...  

A virological survey for avian influenza (AI) and Newcastle disease (ND) was conducted in two selected live bird markets (LBMs), namely Kaptan Bazar and Karwan Bazar in Dhaka city, Bangladesh from August 2011 to July 2012. A total of 513 dead chickens were collected. An immune-chromatographic rapid antigen test for Type A influenza virus and both conventional and real time RT-PCR were used for the detection and characterization of AI and ND viruses. All carcasses were first screened by the rapid antigen test kit and 93 were positive for Type A influenza virus. RT-PCR on a representative number of rapid antigen test positive samples (n = 24) confirmed the presence of Type A influenza virus and mostly H5 influenza virus (22 out of 24 tested samples). Influenza rapid test negative samples (n = 420) were subjected to routine necropsy. Heat stress, suffocation and physical injury were the most common cause of mortality (163 cases), followed by ND, suspected to be the cause of 85 deaths. On molecular investigation of these 85 samples, the presence of ND virus was confirmed in 59 and AI virus in 6; 15 were negative for both ND and AI viruses and 5 were unsuitable for investigation. Among the 59 ND confirmed cases 18 also contained AI virus. In summary, out of 513 carcasses 117 (22.81%) contained AI virus and 59 (11.50%) contained ND virus. Eighteen (3.51%) carcasses contained both AI and ND viruses. The findings suggest that both AI and ND should be considered as major threats to the poultry industry.Bangl. vet. 2016. Vol. 33, No. 1, 8-15


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