scholarly journals Potential applications of the rapid COVID-19 antibody test kit screening in comparison to the RT-PCR in patients and personnel at the Department of Obstetrics and Gynecology.

2021 ◽  
Author(s):  
Amarin Narkwichean ◽  
Wittaya Jomoui ◽  
Wipada Laosooksathit ◽  
Tanawin Nopsopon ◽  
Krit Pongpirul
Keyword(s):  
False Positive Rate ◽  
Antibody Test ◽  
Medical Personnel ◽  
Obstetrics And Gynecology ◽  
Rt Pcr ◽  
Risk Area ◽  
Asymptomatic Patients ◽  
Test Kit ◽  
Potential Applications ◽  
Rapid Antibody

Objective To explore potential applications of the rapid antibody test for COVID-19 screening, in comparison to RT-PCR, for emergency obstetric and gynecological procedures, and medical personnel in the Department of Obstetrics and Gynecology. Methods A cross-sectional study was conducted in expected 290 participants: 230 patients and 60 medical staff, during the four-month national COVID-19 outbreak period (Aug-Sep 2020, and Dec 2020-Jan 2021). All participants underwent both rapid antibody tests and RT-PCR (at admission for patients). Results A total of 270 participants completed the study. Fever and URI symptoms were present in 6/210 patients (2.8%) while one patient (0.5%) had a history of traveling to a high-risk area. However, only two (1%) asymptomatic patients had positive IgM results. Concerning the medical personnel, 10% fell into the patient under investigation (PUI) category. 4/60 (6.7%) IgM positive was observed in the staff cohort in which 3/4 came from non-PUI participants. Neither participant had RT-PCR positive demonstrating a 1.9% total false positive rate. Conclusion Rapid point-of-care antibody test can be used to screen either a pregnant coming for delivery, a patient who requires urgent/emergency operative procedures, or medical personnel, at least in the defined lower-prevalence COVID-19 situation.

scholarly journals Validation of rapid antibody (IgG-IgM) test kit for SARS COV-2 infection in Qatar

2021 ◽  
Author(s):  
Jesha Mundodan ◽  
Samina Hasnain ◽  
Hayat Khogali ◽  
Soha Shawqi Al Bayat ◽  
Dina Ali ◽  
...  
Keyword(s):  
Predictive Value ◽  
Local Population ◽  
Rapid Test ◽  
Antibody Test ◽  
Molecular Testing ◽  
Rt Pcr ◽  
Test Kit ◽  
Asymptomatic Individuals ◽  
Sensitivity Specificity ◽  
Rapid Antibody

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.

scholarly journals Development and clinical evaluation of a rapid antibody lateral flow assay for the diagnosis of SARS-CoV-2 infection

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kesheng Li ◽  
Chongxiang Tong ◽  
Xiaoqin Ha ◽  
Chaoning Zeng ◽  
Xia Chen ◽  
...  
Keyword(s):  
Clinical Evaluation ◽  
False Negative ◽  
Antibody Test ◽  
Cross Reactivity ◽  
Respiratory Pathogens ◽  
Analytical Sensitivity ◽  
N Protein ◽  
Test Kit ◽  
Positive Rate ◽  
Rapid Antibody

Abstract Background The novel coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has quickly spread worldwide since its outbreak in December 2019. One of the primary measures for controlling the spread of SARS-CoV-2 infection is an accurate assay for its diagnosis. SARS-CoV-2 real-time PCR kits suffer from some limitations, including false-negative results in the clinic. Therefore, there is an urgent need for the development of a rapid antibody test kit for COVID-19 diagnosis. Methods The nuclear capsid protein (N) and spike protein 1 (S1) fragments of SARS-CoV-2 were expressed in Escherichia coli, and rapid antibody-based tests for the diagnosis of SARS-CoV-2 infection were developed. To evaluate their clinical applications, the serum from COVID-19 patients, suspected COVID-19 patients, recovering COVID-19 patients, patients with general fever or pulmonary infection, doctors and nurses who worked at the fever clinic, and health professionals was analyzed by the rapid antibody test kits. The serum from patients infected with Mycoplasma pneumoniae and patients with respiratory tract infection was further analyzed to test its cross-reactivity with other respiratory pathogens. Results A 47 kDa N protein and 67 kDa S1 fragment of SARS-CoV-2 were successfully expressed, purified, and renatured. The rapid antibody test with recombinant N protein showed higher positive rate than the rapid IgM antibody test with recombinant S1 protein. Clinical evaluation showed that the rapid antibody test kit with recombinant N protein had 88.56 % analytical sensitivity and 97.42 % specificity for COVID-19 patients, 53.48 % positive rate for suspected COVID-19 patients, 57.14 % positive rate for recovering COVID-19 patients, and 0.5−0.8 % cross-reactivity with other respiratory pathogens. The analytical sensitivity of the kit did not significantly differ in COVID-19 patients with different disease courses (p < 0.01). Conclusions The rapid antibody test kit with recombinant N protein has high specificity and analytical sensitivity, and can be used for the diagnosis of SARS-CoV-2 infection combined with RT-PCR.

scholarly journals Clinical and Epidemiologic Evaluation of Inconclusive COVID-19 PCR Results Using a Quantitative Algorithm

2020 ◽  
Author(s):  
Shangxin Yang ◽  
Nicholas Stanzione ◽  
Daniel Z Uslan ◽  
Omai B Garner ◽  
Annabelle de St Maurice
Keyword(s):  
False Positive ◽  
Infection Prevention ◽  
False Positive Rate ◽  
Antibody Test ◽  
Test Results ◽  
Asymptomatic Patients ◽  
Positive Rate ◽  
Control And Prevention ◽  
Polymerase Chain ◽  
Asymptomatic Individuals

Abstract Objectives The inconclusive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) result causes confusion and delay for infection prevention precautions and patient management. We aimed to develop a quantitative algorithm to assess and interpret these inconclusive results. Methods We created a score-based algorithm by combining laboratory, clinical, and epidemiologic data to evaluate 69 cases with inconclusive coronavirus disease 2019 (COVID-19) PCR results from the Centers for Disease Control and Prevention (CDC) assay (18 cases) and the TaqPath assay (51 cases). Results We determined 5 (28%) of 18 (CDC assay) and 20 (39%) of 51 (TaqPath assay) cases to be false positive. Lowering the cycle threshold cutoff from 40 to 37 in the TaqPath assay resulted in a dramatic reduction of the false-positive rate to 14%. We also showed testing of asymptomatic individuals is associated with a significantly higher probability of having a false-positive result. Conclusions A substantial percentage of inconclusive SARS-CoV-2 PCR results can be false positive, especially among asymptomatic patients. The quantitative algorithm we created was shown to be effective and could provide a useful tool for clinicians and hospital epidemiologists to interpret inconclusive COVID-19 PCR results and provide clinical guidance when additional PCR or antibody test results are available.

scholarly journals Cohort Study: The Accuracy of Screening Methods of COVID-19 in Pregnancy: Practical Approach in Low Resources Health Services

2021 ◽  
Author(s):  
Muhammad Ilham Aldika Akbar ◽  
Khanizyah Erza Gumilar ◽  
Eccita Rahestyningtyas ◽  
Manggala Pasca Wardhana ◽  
Pungky Mulawardhana ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Pregnant Women ◽  
Antibody Test ◽  
Screening Methods ◽  
Rt Pcr ◽  
Predictive Values ◽  
X Ray ◽  
Low Middle Income Countries ◽  
Chest X Ray ◽  
Rapid Antibody

Background All pregnant women in labor should be universally screened for Coronavirus Disease 2019 (COVID-19) during pandemic periods using Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) test. In many low-middle income countries, screening method was developed as an initial examination because of limited availability of RT-PCR tests. Objectives This study aims to evaluate the screening methods of COVID-19 accuracy in pregnant women. Material and Methods We recruited all pregnant women with suspicion of COVID-19 from April - August 2020 at Universitas Airlangga hospital, Surabaya, Indonesia. The participant was divided into two groups based on RT-PCR results: COVID-19 and non-COVID-19 group. The proportion of positive signs & symptoms, rapid antibody test, abnormal findings in chest x-ray, and neutrophil to lymphocyte ratio (NLR) value were then compared between both groups. The sensitivity, specificity, positive predictive value (PPV), negative predictive values (NPV), and diagnostic accuracy (DOR) were calculated. Results A total 141 pregnant women with suspected COVID-19 cases were recruited for this study. This consist of 62 COVID-19 cases (43.9%) and 79 non COVID-19 pregnant women (56.1%). The sensitivity, spesificity, PPV, NPV, and diagnostic accuracy of each parameter are as follow: clinical sign & symptoms (24.19%, 75.95%, 3.92%, 96.11%, 65.87%), rapid antibody test (72.73%, 35.06%, 4.35%, 96.94%, 36.53%), chest x-ray (40.68%, 59.45%, 3.92%, 96.11%, 58.76%), and NLR > 5.8 (41.38%, 72%, 5.66%, 96.80%, 70.81%). Conclusions The use of combined screening methods can classify pregnant women with high-risk COVID-19 before definitively diagnosed with RT-PCR. This practice will help to reduce RT-PCR need in a limited resources country.

scholarly journals Diagnostic Indexes of a Rapid IgG/IgM Combined Antibody Test for SARS-CoV-2

2020 ◽  
Author(s):  
Liu Ying ◽  
Liu Yue-ping ◽  
Diao Bo ◽  
Ren Feifei ◽  
Wang Yue ◽  
...  
Keyword(s):  
Predictive Value ◽  
Antibody Test ◽  
Turnaround Time ◽  
Ease Of Use ◽  
Sample Collection ◽  
Rt Pcr ◽  
Illness Onset ◽  
Test Kit ◽  
Combined Test ◽  
Sensitivity Specificity

[Abstract]ObjectiveCoronavirus disease 2019 (COVID-19) has become pandemic in the world. The need for IgG-IgM combined antibody test is booming, but data on diagnostic indexes evaluation was inadequate. The aim of this study was to evaluate diagnostic indexes of a rapid IgG-IgM combined antibody test for SARS-CoV-2.MethodsA total of 179 patients were enrolled. Serum were collected for IgG-IgM combined antibody test and corresponding nasal and pharyngeal swab specimens were collected for SARS-CoV-2 RT-PCR. According to SARS-CoV-2 RT-PCR results, patients under study were categorized as PCR positive group in 90 patients and PCR negative group in 89 patients.Results1. Of the 90 PCR positive samples, 77 were tested positive by SARS-CoV-2 IgG-IgM test kit, yielding a sensitivity of 85.6%. Meanwhile, of the 89 PCR negative sample, 8 samples were detected positive, resulting in a specificity of 91%. Positive predictive value, negative predictive value and accuracy of this test kit was 95.1%, 82.7%, and 88.3%, respectively. Kappa efficiency between IgG/IgM test kit and RT-PCR were 0.75. 2. Accuracy in mild/common and severe/critical subgroup were 73.9% and 97.7%, respectively. Accuracy in clinical confirmed, suspected cases and other disease subgroups were 70%, 60%, and 100%, respectively. 3. Patients were further divided into ‘0 - 7’, ‘8 - 15’ and ‘>= 16’ groups according to the time from illness onset to sample collection. Sensitivity, specificity and accuracy in these three groups were 18.8%, 77.8% and 40%; 100%, 50% and 87.5%; 100%, 64.3%, and 93.9, respectively.ConclusionThe sensitivity and specificity of this ease-of-use IgG/IgM combined test kit were adequate, plus short turnaround time, no specific requirements for additional equipment or skilled technicians, all of these collectively contributed to its competence for mass testing. At the current stage, it cannot take the place of SARA-CoV-2 nucleic acid RT-PCR, but can be served as a complementary option for RT-PCR. The combination of RT-PCR and IgG-IgM combined test kit could provide further insight into SARS-CoV-2 infection diagnosis.

EVALUATION OF PERFORMANCE OF NINE SEROLOGICALASSAYS FOR THE DETECTION OF SARS-COV-2 ANTIBODIES.

2021 ◽  
pp. 60-62
Author(s):  
Tagajdid Mohamed Rida ◽  
Konzi Clémence ◽  
El Kochri Safae ◽  
Elannaz Hicham ◽  
Abi Rachid ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Current Knowledge ◽  
False Negative ◽  
Antibody Test ◽  
Antibody Detection ◽  
Rt Pcr ◽  
Igg Antibody ◽  
Serological Tests ◽  
Blood Samples ◽  
Test Kit

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.

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 ◽  
...  
Keyword(s):  
Rapid Test ◽  
Antibody Test ◽  
Immunofluorescence Assay ◽  
Lateral Flow ◽  
Antibody Detection ◽  
Rt Pcr ◽  
Igg Antibody ◽  
Reliable Determination ◽  
Test Kit ◽  
Serological Status

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.

scholarly journals Comparison of Rapid Antibody Test and Thorax Computed Tomography Results in Patients who Underwent RT-PCR with the Pre-Diagnosis of COVID-19

2021 ◽  
Author(s):  
İlker Kızıloglu ◽  
Aslı Şener ◽  
Neslihan Siliv
Keyword(s):  
Computed Tomography ◽  
Emergency Department ◽  
Predictive Value ◽  
Antibody Test ◽  
Nasopharyngeal Swab ◽  
Test Results ◽  
Rt Pcr ◽  
Hospital Data ◽  
Thorax Ct ◽  
Rapid Antibody

Introduction: In this study, it is planned to compare the RT-PCR test, which is the gold standard in the diagnosis of COVID-19, with Thorax computed tomography (CT) and rapid antibody test results. Methods: Patients who were admitted to the emergency service of İzmir Çiğli Training and Research Hospital between 01.04.2020 and 31.05.2020 and who were suspected of having COVID-19 infection were included in the study. The medical records of the patients were retrospectively analyzed through the hospital data processing database. Age, gender, hospitalization, status of home quarantine, real-time reverse transcription-polymerase chain reaction (RT-PCR), thorax CT and rapid antibody test results of the patients were examined. The relationship between RT-PCR, thorax CT and rapid antibody test results were compared statistically. Results: A total of 181 patients, 115 (63.5%) male and 66 (36.5%) female, with an average age of 56.4 ± 18.06 years were included in the study. The nasopharyngeal swab PCR result obtained at the first admission of the patients to the emergency department was positive in 71 (39.2%) patients. Thorax CT was performed in 173 (95.6%) patients who applied to the emergency department, and 112 (64.7%) of them had findings that could be compatible with COVID-19. According to the thorax CT findings in patients, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting COVID-19 infection were respectively; 76.1%, 43.1%, 48.2% and 72.1% (ĸ: 0.176, p <0.001). In our study, the mortality rate for COVID-19 was found to be 2.8%. Conclusion: Rapid antibody test and thorax CT examinations were found to have low diagnostic value in patients who admitted to the emergency department of our hospital and whose first RT-PCR SARS-CoV-2 test was positive. Studies involving larger patient groups are needed for their use alone in diagnosis and screening.

scholarly journals Alternative or Complementary Role of Serological Rapid Antibody Test in the Management of Possible COVID-19 Cases

2020 ◽  
Author(s):  
Fatma Yildirim ◽  
Pinar Yildiz Gulhan ◽  
Ozlem Ercen Diken ◽  
Aylin Capraz ◽  
Meltem Simsek ◽  
...  
Keyword(s):  
Antibody Test ◽  
Test Method ◽  
Nasopharyngeal Swab ◽  
Common Symptom ◽  
Rt Pcr ◽  
Igg Antibody ◽  
Serological Tests ◽  
Female Ratio ◽  
The Mean ◽  
Rapid Antibody

Background: Although the gold diagnostic method for COVID-19 is accepted as the detection of viral particles by reverse transcription polymerase chain reaction (RT-PCR), serology testing for SARS-CoV-2 is at increased demand. A primary aim for utilization of serological tests are to better quantify the number of COVID-19 cases including those RT-PCR samples were negative but showing clinical and radiological signs of COVID-19. In this study, we aimed to report the features of the patients that were diagnosed and treated as possible COVID-19 cases whose multiple nasopharyngeal swab samples were negative by RT-PCR but serological IgM/IgG antibody against SARS-CoV-2 were detected by rapid antibody test. Method: We retrospectively analyzed eighty suspected COVID-19 cases that have at least two negative consecutive COVID-19 PCR test and were subjected to serological rapid antibody test. Result: The specific antibodies against SARS-CoV-2 were detected as positive in twenty-two patients. The mean age of patient group was 63.2+-13.1 years old with male /female ratio 11/11. Cough was the most common symptom with 90.9%. Most common presenting chest CT findings were bilateral ground glass opacities (77.2%) and alveolar consolidations (50.09%). The mean duration from symptom initiation to hospital admission, to hospitalization, to treatment initiation and to detection of antibody positivity were 8.6 +- 7.2, 11.2 +- 5.4, 7.9 +- 3.2 and 24 +- 17 days, respectively. Conclusion: Our study demonstrated the feasibility of COVID-19 diagnosis based on rapid antibody test in the cases of patients whose RT-PCR samples were negative. We suggest that the detection of antibodies against SARS-CoV-2 with rapid antibody test should be included in the diagnostic algorithm in suspected COVID-19 patients.

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