scholarly journals Development and Efficacy of Lateral Flow Point-of-Care Testing Devices for Rapid and Mass COVID-19 Diagnosis by the Detections of SARS-CoV-2 Antigen and Anti-SARS-CoV-2 Antibodies

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1760
Author(s):  
Wen-Yeh Hsieh ◽  
Cheng-Han Lin ◽  
Tzu-Ching Lin ◽  
Chao-Hsu Lin ◽  
Hui-Fang Chang ◽  
...  
Keyword(s):  
Large Scale ◽  
Point Of Care ◽  
Standard Procedure ◽  
Surface Enhanced Raman Spectroscopy ◽  
Lateral Flow ◽  
Control Measures ◽  
Nucleic Acid Amplification ◽  
Antibody Detection ◽  
Infection Prevention And Control ◽  
Antigen Tests

The COVID-19 pandemic is an ongoing global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2020–2021. COVID-19 is becoming one of the most fatal pandemics in history and brings a huge challenge to the global healthcare system. Opportune detection, confinement, and early treatment of infected cases present the first step in combating COVID-19. Diagnosis via viral nucleic acid amplification tests (NAATs) is frequently employed and considered the standard procedure. However, with an increasing urge for point-of-care tests, rapid and cheaper immunoassays are widely utilized, such as lateral flow immunoassay (LFIA), which can be used for rapid, early, and large-scale detection of SARS-CoV-2 infection. In this narrative review, the principle and technique of LFIA applied in COVID-19 antigen and antibody detection are introduced. The diagnostic sensitivity and specificity of the commercial LFIA tests are outlined and compared. Generally, LFIA antigen tests for SARS-CoV-2 are less sensitive than viral NAATs, the “gold standard” for clinical COVID-19 diagnosis. However, antigen tests can be used for rapid and mass testing in high-risk congregate housing to quickly identify people with COVID-19, implementing infection prevention and control measures, thus preventing transmission. LFIA anti-SARS-CoV-2 antibody tests, IgM and/or IgG, known as serology tests, are used for identification if a person has previously been exposed to the virus or vaccine immunization. Notably, advanced techniques, such as LFT-based CRISPR-Cas9 and surface-enhanced Raman spectroscopy (SERS), have added new dimensions to the COVID-19 diagnosis and are also discussed in this review.

scholarly journals Context-Specific Procedures for the Diagnosis of Human Schistosomiasis – A Mini Review

2021 ◽  
Vol 2 ◽  
Author(s):  
Pytsje T. Hoekstra ◽  
Govert J. van Dam ◽  
Lisette van Lieshout
Keyword(s):  
Diagnostic Tests ◽  
Point Of Care ◽  
Public Health Problem ◽  
Nucleic Acid Amplification ◽  
Antibody Detection ◽  
Infection Model ◽  
Related Factors ◽  
Human Schistosomiasis ◽  
Diagnostic Approaches ◽  
Context Specific

Schistosomiasis is a parasitic disease caused by trematode blood flukes of the genus Schistosoma, affecting over 250 million people mainly in the tropics. Clinically, the disease can present itself with acute symptoms, a stage which is relatively more common in naive travellers originating from non-endemic regions. It can also develop into chronic disease, with the outcome depending on the Schistosoma species involved, the duration and intensity of infection and several host-related factors. A range of diagnostic tests is available to determine Schistosoma infection, including microscopy, antibody detection, antigen detection using the Point-Of-Care Circulating Cathodic Antigen (POC-CCA) test and the Up-Converting Particle Lateral Flow Circulating Anodic Antigen (UCP-LF CAA) test, as well as Nucleic Acid Amplification Tests (NAATs) such as real-time PCR. In this mini review, we discuss these different diagnostic procedures and explore their most appropriate use in context-specific settings. With regard to endemic settings, diagnostic approaches are described based on their suitability for individual diagnosis, monitoring control programs, determining elimination as a public health problem and eventual interruption of transmission. For non-endemic settings, we summarize the most suitable diagnostic approaches for imported cases, either acute or chronic. Additionally, diagnostic options for disease-specific clinical presentations such as genital schistosomiasis and neuro-schistosomiasis are included. Finally, the specific role of diagnostic tests within research settings is described, including a controlled human schistosomiasis infection model and several clinical studies. In conclusion, context-specific settings have different requirements for a diagnostic test, stressing the importance of a well-considered decision of the most suitable diagnostic procedure.

A prospective nationwide observational study of agreement of antigen tests on oral pharyngeal swabs or less invasive testing with RT-qPCR, for detecting SARS-CoV-2 in adults: Protocol description (Preprint)

2021 ◽  
Author(s):  
Uffe Vest Schneider ◽  
Jenny Dahl Knudsen ◽  
Anders Koch ◽  
Nikolai Søren Kirkby ◽  
Jan Gorm Lisby
Keyword(s):  
Confidence Intervals ◽  
Predictive Value ◽  
Large Scale ◽  
Reference Method ◽  
Lateral Flow ◽  
Clinical Samples ◽  
Sampling Location ◽  
Analytical Sensitivity ◽  
Clinical Sensitivity ◽  
Antigen Tests

BACKGROUND The SARS-CoV-2 pandemic has resulted in an unprecedented level of world-wide testing for epidemiologic and diagnostic purposes, and due to the extreme need for tests, the gold standard reverse transcription polymerase chain reaction (RT-qPCR) testing capacity has been unable to meet the overall global testing demand. Consequently, although current literature has shown the sensitivity of rapid antigen tests (RATs) to be inferior to RT-qPCR, RATs have been implemented on a large scale without solid data on performance. OBJECTIVE This study will compare analytical and clinical sensitivities and specificities of 50 lateral flow or laboratory based RATs and three Strand Invasion Based Amplification (SIBA)-rt-PCR tests from 30 manufacturers to RT-qPCR on samples obtained from the deep oropharynx. In addition, the study will compare sensitivities and specificities of the included RATs as well as RT-qPCR on clinical samples obtained from the deep oropharynx, anterior nasal cavity, saliva, deep nasopharynx and expired air to RT-qPCR from deep oropharyngeal samples. METHODS In the prospective part of the study, 200 individuals found SARS-CoV-2 positive and 200 individuals found SARS-CoV-2 negative by routine RT-qPCR testing will be re-tested with each RAT applying RT-qPCR as the reference method. In the retrospective part of the study, 304 deep oropharyngeal cavity swabs divided into four groups based on RT-qPCR Cq levels will be tested by each RAT. RESULTS The results will be reported in several manuscripts with different aims. The first manuscript will report retrospective (analytical sensitivity, overall and stratified into different Cq range groups) and prospective (clinical sensitivity) data for RATs with RT-qPCR results as the reference method. The second manuscript will report results for RAT based on anatomical sampling location. The third manuscript will compare different anatomical sampling locations by RT-qPCR testing. The fourth manuscript will focus on RATs that rely on central laboratory testing. Test from four different manufactures will be compared for analytical performance data on retrospective deep oropharyngeal swab samples. The fifth manuscript will report the results of four RATs applied both as professional use and as self-test. The last manuscript will report the results from two breath tests participating in the study. Comparison of sensitivity and specificity between RATs will be done using McNemar for paired samples and chi-squared test for unpaired samples. Comparison of PPV and NPV between RATs will be done by bootstrap test. 95 % confidence intervals for sensitivity, specificity, positive predictive value and negative predictive value are calculated as bootstrap confidence intervals CONCLUSIONS The study will compare the sensitivities of a large number of RATs for SARS-CoV-2 compared to RT-qPCR and will address whether lateral flow based RATs test differ significantly from laboratory based RATS. The anatomical test location for both RAT and RT-qPCR will be compared. CLINICALTRIAL ClinicalTrials.gov NCT04913116

Correlation of COVID-19 antigen test and CBNAAT results at a single tertiary care hospital in North India: an experience

2021 ◽  
Vol 8 (5) ◽  
pp. 2427
Author(s):  
Surbhi Gupta ◽  
Anju Shukla ◽  
Poonam Singh ◽  
Areena H. Siddiqui
Keyword(s):  
Tertiary Care Hospital ◽  
Point Of Care ◽  
Tertiary Care ◽  
Uttar Pradesh ◽  
Nucleic Acid Amplification ◽  
North India ◽  
Care Hospital ◽  
Antigen Test ◽  
Discordant Group ◽  
Antigen Tests

Background: Nucleic acid amplification test (NAAT) is considered gold standard in the molecular diagnosis of CoV-2 infection but since it is costly, labor intensive and needs technical expertise, rapid chromatographic immunoassay for the qualitative detection of specific antigens to SARS CoV-2 have been devised. Objectives of this study was to compare the results of Antigen test and NAAT for CoV-2 infection carried out during the months of July and August 2020 by single tertiary care hospital in Lucknow, Uttar Pradesh and to determine the utility of rapid antigen test in the SARS CoV-2 diagnosis.Methods: All the patients who came to our hospital seeking admission during July 2020 and August 2020 were included in the study. A total of 1000 patients were included in this study.Results: Out of a total 1000 cases which were included in the study, 769 cases (76.9%) were found to be SARS CoV-2 negative by both antigen and CBNAAT, 100 cases (10.0%) were SARS CoV-2 positive by both antigen and CBNAAT tests. But in 131 cases (13.1%), antigen was not able to pick up the disease. It was also found that the Cycle Threshold (Ct) value for the discordant group was higher (Mean E= 28, Mean N2=33) when compared to the group where antigen was positive.Conclusions: The present study establishes the role of rapid antigen tests in contributing to the quick, point of care diagnosis of SARS CoV-2. These assays are safe, simple, and fast and can be used in local clinics and hospitals. These tests are very important for real-time patient management and infection control decision.

scholarly journals Point-of-Care Diagnostic Tools for Surveillance of SARS-CoV-2 Infections

2021 ◽  
Vol 9 ◽  
Author(s):  
Dhanasekaran Sakthivel ◽  
David Delgado-Diaz ◽  
Laura McArthur ◽  
William Hopper ◽  
Jack S. Richards ◽  
...  
Keyword(s):  
Large Scale ◽  
Clinical Symptoms ◽  
Point Of Care ◽  
Cost Effective ◽  
Nucleic Acid Amplification ◽  
Diagnostic Tools ◽  
Rt Pcr ◽  
Serological Tests ◽  
Polymerase Chain ◽  
Effective Public Health

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a recently emerged and highly contagious virus that causes coronavirus disease 2019 (COVID-19). As of August 24, 2021, there were more than 212 million confirmed COVID-19 cases and nearly 4.4 million deaths reported globally. Early diagnosis and isolation of infected individuals remains one of the most effective public health interventions to control SARS-CoV-2 spread and for effective clinical management of COVID-19 cases. Currently, SARS-CoV-2 infection is diagnosed presumptively based on clinical symptoms and confirmed by detecting the viral RNA in respiratory samples using reverse transcription polymerase chain reaction (RT-PCR). Standard RT-PCR protocols are time consuming, expensive, and technically demanding, which makes them a poor choice for large scale and point-of-care screening in resource-poor settings. Recently developed isothermal nucleic acid amplification tests (iNAAT), antigen and/or serological tests are cost-effective to scale COVID-19 testing at the point-of-care (PoC) and for surveillance activities. This review discusses the development of rapid PoC molecular tools for the detection and surveillance of SARS-CoV-2 infections.

scholarly journals IFCC interim guidelines on rapid point-of-care antigen testing for SARS-CoV-2 detection in asymptomatic and symptomatic individuals

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mary Kathryn Bohn ◽  
Giuseppe Lippi ◽  
Andrea R. Horvath ◽  
Rajiv Erasmus ◽  
Matthias Grimmler ◽  
...  
Keyword(s):  
Clinical Chemistry ◽  
Point Of Care ◽  
Nucleic Acid Amplification ◽  
Test Interpretation ◽  
Suitable Alternative ◽  
Target Populations ◽  
Evaluation Test ◽  
Conventional Instrumentation ◽  
Antigen Tests ◽  
Antigen Testing

Abstract With an almost unremittent progression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections all around the world, there is a compelling need to introduce rapid, reliable, and high-throughput testing to allow appropriate clinical management and/or timely isolation of infected individuals. Although nucleic acid amplification testing (NAAT) remains the gold standard for detecting and theoretically quantifying SARS-CoV-2 mRNA in various specimen types, antigen assays may be considered a suitable alternative, under specific circumstances. Rapid antigen tests are meant to detect viral antigen proteins in biological specimens (e.g. nasal, nasopharyngeal, saliva), to indicate current SARS-CoV-2 infection. The available assay methodology includes rapid chromatographic immunoassays, used at the point-of-care, which carries some advantages and drawbacks compared to more conventional, instrumentation-based, laboratory immunoassays. Therefore, this document by the International Federation for Clinical Chemistry and Laboratory Medicine (IFCC) Taskforce on COVID-19 aims to summarize available data on the performance of currently available SARS-CoV-2 antigen rapid detection tests (Ag-RDTs), providing interim guidance on clinical indications and target populations, assay selection, and evaluation, test interpretation and limitations, as well as on pre-analytical considerations. This document is hence mainly aimed to assist laboratory and regulated health professionals in selecting, validating, and implementing regulatory approved Ag-RDTs.

scholarly journals An Update on Advances in COVID-19 Laboratory Diagnosis and Testing Guidelines in India

2021 ◽  
Vol 9 ◽  
Author(s):  
K. S. Rajesh Kumar ◽  
Suhail Sayeed Mufti ◽  
Vinu Sarathy ◽  
Diganta Hazarika ◽  
Radheshyam Naik
Keyword(s):  
Large Scale ◽  
Vaccine Development ◽  
Point Of Care ◽  
Diagnostic Testing ◽  
Public Health Intervention ◽  
Laboratory Diagnosis ◽  
Accurate Diagnosis ◽  
Nucleic Acid Amplification ◽  
Rt Pcr ◽  
Outbreak Management

The declaration of COVID-19 as a global pandemic has warranted the urgent need for technologies and tools to be deployed for confirming diagnosis of suspected cases. Diagnostic testing for COVID-19 is critical for understanding epidemiology, contract-tracing, case management, and to repress the transmission of the SARS-CoV-2. Currently, the Nucleic Acid Amplification Test (NAAT)-based RT-PCR technique is a gold standard test used for routine diagnosis of COVID-19 infection. While there are many commercially available RT-PCR assay kits available in the market, selection of highly sensitive, specific, and validated assays is most crucial for the accurate diagnosis of COVID-19 infection. Laboratory diagnosis of SARS-CoV-2 is extremely important in the disease and outbreak management. Development of rapid point of care tests with better sensitivity and specificity is the critical need of the hour as this will help accurate diagnosis and aid in containing the spread of SARS-CoV-2 infection. Early detection of viral infection greatly enhances implementation of specific public health intervention, such as infection control, environmental decontamination, and the closure of specific high-risk zones. Large-scale sequencing of SARS-CoV-2 genome isolated from affected populations across the world needs to be carried to monitor mutations that might affect performance of molecular tests. Creation of genome repositories and open-source genetic databases for use by global researchers is clearly the way forward to manage COVID-19 outbreak and accelerate vaccine development. This review summarizes various molecular diagnostics methods, technical guidelines, and advanced testing strategies adopted in India for laboratory diagnosis of COVID-19.

scholarly journals Engineering luminescent biosensors for point-of-care SARS-CoV-2 antibody detection

2020 ◽  
Author(s):  
Susanna K. Elledge ◽  
Xin X. Zhou ◽  
James R. Byrnes ◽  
Alexander J. Martinko ◽  
Irene Lui ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Low Cost ◽  
Lateral Flow ◽  
Antibody Detection ◽  
Lateral Flow Assays ◽  
Quantitative Results ◽  
Development And Validation ◽  
Antibody Tests ◽  
Split Luciferase

Current serology tests for SARS-CoV-2 antibodies mainly take the form of enzyme-linked immunosorbent assays or lateral flow assays, with the former being laborious and the latter being expensive and often lacking sufficient sensitivity and scalability. Here we present the development and validation of a rapid, low-cost solution-based assay to detect antibodies in serum, plasma, whole blood, and saliva, using rationally designed split luciferase antibody biosensors (spLUC). This new assay, which generates quantitative results in as short as 5 minutes, substantially reduces the complexity and improves the scalability of COVID-19 antibody tests for point-of-care and broad population testing.

scholarly journals Overcoming Current and Preventing Future Nosocomial Outbreaks during the COVID-19 Pandemic: Lessons Learned at Three Hospitals in Japan

2021 ◽  
Vol 18 (19) ◽  
pp. 10226
Author(s):  
Makiko Komasawa ◽  
Myo Nyein Aung ◽  
Kiyoko Saito ◽  
Mitsuo Isono ◽  
Go Tanaka ◽  
...  
Keyword(s):  
Infection Control ◽  
Large Scale ◽  
Practical Knowledge ◽  
Care Delivery ◽  
Lessons Learned ◽  
Control Measures ◽  
Infection Prevention And Control ◽  
Infection Control Measures ◽  
Health Care Delivery Systems ◽  
And Control

Hospitals are increasingly challenged by nosocomial infection (NI) outbreaks during the ongoing coronavirus disease 2019 (COVID-19) pandemic. Although standardized guidelines and manuals regarding infection prevention and control (IPC) measures are available worldwide, case-studies conducted at specified hospitals that are required to cope with real settings are limited. In this study, we analyzed three hospitals in Japan where large-scale NI outbreaks occurred for hints on how to prevent NI outbreaks. We reviewed openly available information from each hospital and analyzed it applying a three domain framework: operation management; identification of infection status; and infection control measures. We learned that despite having authorized infection control teams and using existing standardized IPC measures, SARS-CoV-2 may still enter hospitals. Early detection of suspected cases and confirmation by PCR test, carefully dealing with staff-to-staff transmission were the most essential factors to prevent NI outbreaks. It was also suggested that ordinary training on IPC for staff does not always provide enough practical knowledge and skills; in such cases external technical and operational supports are crucial. It is expected that our results will provide insights into preventing NI outbreaks of COVID-19, and contribute to mitigate the damage to health care delivery systems in various countries.

scholarly journals Reducing the Cost of Rapid Antigen Tests through Swab Pooling and Extraction in a Device

2021 ◽  
Author(s):  
Tim Berking ◽  
Sabrina G. Lorenz ◽  
Alexander Ulrich ◽  
Joachim Greiner ◽  
Clemens Richert
Keyword(s):  
Large Scale ◽  
Signal To Noise Ratio ◽  
Point Of Care ◽  
Positive Control ◽  
Extraction Buffer ◽  
Large Scale Testing ◽  
Antigen Tests ◽  
Set Up ◽  
Cost Of Materials ◽  
The Cost

AbstractThe COVID-19 pandemic places a significant stress on the viral testing capabilities of many countries. The value of rapid point-of-care (PoC) antigen tests is becoming increasingly clear, but implementing frequent large scale testing is costly. We have developed an inexpensive device for pooling swabs, extracting specimens, and detecting viral antigens with a commercial lateral flow assay detecting the nucleocapsid protein of SARS-CoV-2 as antigen. The holder of the device can be produced locally through 3D printing. The extraction and the elution can be performed with the entire set-up encapsulated in a transparent bag, minimizing the risk of infection for the operator. With 6 swabs holding approx. 0.1 mL specimen each and 0.35 mL extraction buffer, 43±6 % (n= 8) of the signal for an individual extraction of a positive control standard was obtained. Image analysis still showed a signal-to-noise ratio of ≥ 7 upon further eight-fold dilution. Our current total cost of materials is below $ 2 per tested person or 20% of our cost for an individual PoC test. These findings suggest that pooling can make frequent testing more affordable for schools, universities and other institutions, without decreasing sensitivity to an unacceptable level. Further validation of the method is required.

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

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.

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