scholarly journals FebriDx point-of-care test in patients with suspected COVID-19: a pooled diagnostic accuracy study

2020 ◽  
Author(s):  
Samuel G. Urwin ◽  
B. Clare Lendrem ◽  
Jana Suklan ◽  
Kile Green ◽  
Sara Graziadio ◽  
...  
Keyword(s):  
Laboratory Test ◽  
Diagnostic Accuracy ◽  
Bacterial Infections ◽  
Point Of Care ◽  
Test Accuracy ◽  
Test Results ◽  
Standard Laboratory ◽  
Rt Pcr ◽  
Accuracy Study ◽  
Test Result

AbstractBackgroundPoint-of-care (POC) tests for COVID-19 could relieve pressure on isolation resource, support infection prevention and control, and help commence more timely and appropriate treatment. We aimed to undertake a systematic review and pooled diagnostic test accuracy study of available individual patient data (IPD) to evaluate the diagnostic accuracy of a commercial POC test (FebriDx) in patients with suspected COVID-19.MethodsA literature search was performed on the 1st of October 2020 to identify studies reporting diagnostic accuracy statistics of the FebriDx POC test versus real time reverse transcriptase polymerase chain reaction (RT-PCR) testing for SARS-CoV-2. Studies were screened for risk of bias. IPD were sought from studies meeting the inclusion and exclusion criteria. Logistic regression was performed to investigate the study effect on the outcome of the RT-PCR test result in order to determine whether it was appropriate to pool results. Diagnostic accuracy statistics were calculated with 95% confidence intervals (CIs).Results15 studies were screened, and we included two published studies with 527 hospitalised patients. 523 patients had valid FebriDx results for Myxovirus resistance protein A (MxA), an antiviral host response protein. The FebriDx test produced a pooled sensitivity of 0.920 (95% CI: 0.875-0.950) and specificity of 0.862 (0.819-0.896) compared with RT-PCR, where there was an estimated true COVID-19 prevalence of 0.405 (0.364-0.448) and overall FebriDx test yield was 99.2%. Patients were tested at a median of 4 days [interquartile range: 2:9] after symptom onset. No differences were found in a sub-group analysis of time tested since the onset of symptoms.ConclusionsBased on a large sample of patients from two studies during the first wave of the SARS-CoV-2 pandemic, the FebriDx POC test had reasonable diagnostic accuracy in a hospital setting with high COVID-19 prevalence, out of influenza season. More research is required to determine how FebriDx would perform in other healthcare settings with higher or lower COVID-19 prevalence, different patient populations, or when other respiratory infections are in circulation.Trial registrationThis work was based on a pooled analysis of anonymised data from two previous studies; the CoV-19POC study, described by Clark et al. (9), the “Southampton study” [ISRCTN:14966673, date registered: 18/03/2020]; and a study described by Karim et al. (13) the “Kettering study”.Lay summaryTests to diagnose COVID-19 are crucial to help control the spread of the disease and to guide treatment. Over the last few months, tests have been developed that can detect the SARS-CoV-2 virus which causes COVID-19. These tests use complex machines in pathology laboratories accepting samples from large geographical areas. Sometimes it takes days for test results to come back. So, to reduce the wait for results, new portable tests are being developed. These point-of-care (POC) tests are designed to work close to where patients require assessment and care such as hospital emergency departments, GP surgeries or care homes. For these new POC tests to be useful, they should ideally be as good as standard laboratory tests so patients get their result quickly and can benefit from the best, safest care.In this study we looked at published research into a new test, FebriDx, which can detect the presence of any viral infection, including infections due to the SARS-CoV-2 virus, as well as bacterial infections which can have similar symptoms. The FebriDx result was compared with that obtained on the same patient’s throat and nose swab and using the standard COVID-19 viral laboratory test. We were able to analyse data from two studies with a total of 523 adult patients who were receiving emergency hospital care with symptoms of COVID-19 during the early stage of the UK pandemic. Almost half of the patients were diagnosed as positive for SARS-CoV-2 virus using standard laboratory COVID-19 viral tests.Our analysis demonstrated that the FebriDx POC test agreed 94 out of 100 times with the standard laboratory test results when FebriDx diagnosed the patient as free from COVID-19. However, FebriDx agreed only 82 out of 100 times with the standard laboratory test when FebriDx indicated that the patient had a COVID-19 infection. These differences have important implications for how these tests could be used. As there were far fewer FebriDx false results when the results of the FebriDx test were negative (6 out of 100) than when the results of the FebriDx test were positive (18 out of 100), we can have more confidence in a negative test result using FebriDx at the POC than a positive FebriDx result.Overall, we have shown that the FebriDx POC test performed quite well during the first wave of the COVID-19 pandemic when compared with laboratory tests, especially when the POC test returned a negative test. For the future, this means that the FebriDx POC test might be helpful in making a rapid clinical decision whether to isolate a patient with COVID-19-like symptoms arriving in a busy emergency department. However, our results indicate it would not completely replace the need to conduct a confirmatory laboratory test in certain cases.There are limitations to our findings. For example, we do not know if FebriDx will work in a similar way with patients in different settings such as in the community or care homes. Similarly, we do not know whether other viral and bacterial infections which cause similar COVID-19 symptoms, and are more common in the autumn and winter months, could influence the FebriDx test accuracy.

scholarly journals A Systematic and Meta-Analysis Review on the Diagnostic Accuracy of Antibodies in the Serological Diagnosis of COVID-19.

2020 ◽  
Author(s):  
Arthur Vengesai ◽  
Herald Midzi ◽  
Maritha Kasambala ◽  
Hamlet Mutandadzi ◽  
Tariro L. Mduluza-Jok ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Point Of Care ◽  
Meta Analysis ◽  
Characteristic Curve ◽  
Test Accuracy ◽  
Rt Pcr ◽  
Summary Receiver Operating Characteristic ◽  
Serological Tests ◽  
Bivariate Model ◽  
Prevalence Studies

Abstract Background: Serological testing based on different antibody types are an alternative method being used to diagnose SARS-CoV-2 and has the potential of having higher diagnostic accuracy compared to the current gold standard RT-PCR. Therefore, the objective of this review was to evaluate the diagnostic accuracy of IgG and IgM based Point-of-care (POC) lateral flow immunoassays (LFIA), chemiluminescence enzyme immunoassay (CLIA), fluorescence enzyme-linked immunoassay (FIA) and ELISA systems that detect SARS-CoV-2 antigens.Method: A systematic literature search was carried out in PubMed, Medline complete and MedRxiv. Studies evaluating the diagnostic accuracy of serological assays for SARS-CoV-2 were eligible. Study selection and data-extraction were done by two authors independently. QUADAS-2 checklist tool was used to assess the quality of the studies. The bivariate model and the hierarchical summary receiver operating characteristic curve model were performed to evaluate the diagnostic accuracy of the serological tests. Subgroup meta-analysis analyses was performed to explore the heterogeneity. Results: The pooled sensitivity for IgG, IgM and IgG-IgM based LFIA tests were 0.5856, 0.4637 and 0.6886 respectively compared to RT-PCR method. The pooled sensitivity for IgG and IgM based CLIA tests were 0.9311 and 0.8516 respectively compared to RT-PCR. The pooled sensitivity the IgG, IgM and IgG-IgM based ELISA tests were 0.8292, 0.8388 and 0.8531 respectively compared to RT-PCR. All tests displayed high specificities ranging from 0.9693 to 0.9991. Among the evaluated tests, IgG based CLIA expressed the highest sensitivity signifying its accurate detection of the largest proportion of infections identified by RT-PCR. ELISA and CLIA tests performed better in terms of sensitivity compared to LFIA. IgG based tests performed better compared to IgM ones expect for the ELISA. Conclusions: We report that IgG-IgM based ELISA tests have the best overall diagnostic test accuracy. Moreover, irrespective of the method, a combined IgG/IgM test seems to be a better choice in terms of sensitivity than measuring either antibody type independently. Given the poor performances of the current LFIA devices there is need for more research on the development of highly sensitivity and specific POC LFIA that are adequate for most individual patient applications and attractive for large sero-prevalence studies.Systematic review registration: PROSPERO Registration Number is: CRD42020179112

scholarly journals Machine Learning Highlights Downtrending of COVID-19 Patients with a Distinct Laboratory Profile

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
He S. Yang ◽  
Yu Hou ◽  
Hao Zhang ◽  
Amy Chadburn ◽  
Lars F. Westblade ◽  
...  
Keyword(s):  
Machine Learning ◽  
New York ◽  
High Risk ◽  
Laboratory Test ◽  
Laboratory Test Result ◽  
Test Results ◽  
Rt Pcr ◽  
Laboratory Test Results ◽  
Laboratory Profile ◽  
Test Result

Background. New York City (NYC) experienced an initial surge and gradual decline in the number of SARS-CoV-2-confirmed cases in 2020. A change in the pattern of laboratory test results in COVID-19 patients over this time has not been reported or correlated with patient outcome. Methods. We performed a retrospective study of routine laboratory and SARS-CoV-2 RT-PCR test results from 5,785 patients evaluated in a NYC hospital emergency department from March to June employing machine learning analysis. Results. A COVID-19 high-risk laboratory test result profile (COVID19-HRP), consisting of 21 routine blood tests, was identified to characterize the SARS-CoV-2 patients. Approximately half of the SARS-CoV-2 positive patients had the distinct COVID19-HRP that separated them from SARS-CoV-2 negative patients. SARS-CoV-2 patients with the COVID19-HRP had higher SARS-CoV-2 viral loads, determined by cycle threshold values from the RT-PCR, and poorer clinical outcome compared to other positive patients without the COVID12-HRP. Furthermore, the percentage of SARS-CoV-2 patients with the COVID19-HRP has significantly decreased from March/April to May/June. Notably, viral load in the SARS-CoV-2 patients declined, and their laboratory profile became less distinguishable from SARS-CoV-2 negative patients in the later phase. Conclusions. Our longitudinal analysis illustrates the temporal change of laboratory test result profile in SARS-CoV-2 patients and the COVID-19 evolvement in a US epicenter. This analysis could become an important tool in COVID-19 population disease severity tracking and prediction. In addition, this analysis may play an important role in prioritizing high-risk patients, assisting in patient triaging and optimizing the usage of resources.

scholarly journals CovidNudge: diagnostic accuracy of a novel lab-free point-of-care diagnostic for SARS-CoV-2

2020 ◽  
Author(s):  
Malick M Gibani ◽  
Christofer Toumazou ◽  
Mohammadreza Sohbati ◽  
Rashmita Sahoo ◽  
Maria Karvela ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Point Of Care ◽  
N Gene ◽  
Hospital Inpatient ◽  
Standard Laboratory ◽  
Rt Pcr ◽  
Viral Transport Medium ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Background Access to rapid diagnosis is key to the control and management of SARS-CoV-2. Reverse Transcriptase- Polymerase Chain Reaction (RT-PCR) testing usually requires a centralised laboratory and significant infrastructure. We describe the development and diagnostic accuracy assessment of a novel, rapid point-of-care RT-PCR test, the DnaNudge platform CovidNudge test, which requires no laboratory handling or sample pre-processing. Methods Nasopharyngeal swabs are inserted directly into a cartridge which contains all reagents and components required for RT-PCR reactions, including multiple technical replicates of seven SARS-CoV-2 gene targets (rdrp1, rdrp2, e-gene, n-gene, n1, n2 and n3) and human ribonuclease P (RNaseP) as a positive control. Between April and May 2020, swab samples were tested in parallel using the CovidNudge direct-to-cartridge platform and standard laboratory RT-PCR using swabs in viral transport medium. Samples were collected from three groups: self-referred healthcare workers with suspected COVID-19 (Group 1, n=280/386; 73%); patients attending the emergency department with suspected COVID-19 (Group 2, n=15/386; 4%) and hospital inpatient admissions with or without suspected COVID-19 (Group 3, n=91/386; 23%). Results Of 386 paired samples tested across all groups, 67 tested positive on the CovidNudge platform and 71 with standard laboratory RT-PCR. The sensitivity of the test varied by group (Group 1 93% [84-98%], Group 2 100% [48-100%] and Group 3 100% [29-100%], giving an average sensitivity of 94.4% (95% confidence interval 86-98%) and an overall specificity of 100% (95%CI 99-100%; Group 1 100% [98-100%]; Group 2 100% [69-100%] and Group 3 100% [96-100%]). Point of care testing performance was comparable during a period of high (25%) and low (3%) background prevalence. Amplification of the viral nucleocapsid (n1, n2, n3) targets were most sensitive for detection of SARS-CoV2, with the assay able to detect 1x104 viral particles in a single swab. Conclusions The CovidNudge platform offers a sensitive, specific and rapid point of care test for the presence of SARS-CoV-2 without laboratory handling or sample pre-processing. The implementation of such a device could be used to enable rapid decisions for clinical care and testing programs.

Death and COVID-19 Anxiety in Home-Quarantined Individuals Aged 65 and Over During the Pandemic

2021 ◽  
pp. 003022282110598
Author(s):  
Hümeyra Aslaner ◽  
Betül Özen ◽  
Zeliha K. Erten ◽  
Mebrure Beyza Gökçek
Keyword(s):  
Polymerase Chain Reaction ◽  
Death Anxiety ◽  
Short Form ◽  
Anxiety Score ◽  
Test Results ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Test Result ◽  
Pcr Test

Urgent measures were taken for those at the age of 65 and over who were at the risk group all over the world due to the COVID-19 pandemic. It is known that many individuals at the age of 65 and over have experienced anxiety due to the uncertainties. This study aimed to determine the anxiety and death anxiety in individuals aged 65 and over who were isolation at home due to being diagnosed with COVID-19 or being in contact during the pandemic process. The study is descriptive and cross-sectional. It was performed with 656 home-quarantined individuals aged between 65–80 years with positive or negative real-time polymerase chain reaction (RT-PCR) test result. A form including questions about the death anxiety and the Coronavirus Anxiety Scale Short Form prepared by the researchers were administered to the individuals by phone call. Of the participants, 49.5% were male. Median COVID-19 anxiety score was 4 (0–18). Anxiety scores of the male and female participants were similar. Participants with negative polymerase chain reaction (PCR) results and those with death anxiety had higher COVID anxiety scores. Death anxiety has increased by 1.661 times in male gender, 1.983 times in RT-PCR positivity and 0.146 times in the presence of symptoms. Individuals with positive COVID-19 test results or those aged 65 and over who had death anxiety and negative COVID-19 test result but who were in home-isolation due to being a contact had higher anxiety score. For this reason, those with death anxiety can be supported in line with their religious beliefs to reduce anxiety. Those with negative PCR test results in quarantine can be adequately informed about the COVID-19.

scholarly journals Risk of bias and limits of reporting in diagnostic accuracy studies for commercial point-of-care tests for respiratory pathogens

2018 ◽  
Vol 146 (6) ◽  
pp. 747-756
Author(s):  
J.M. Hughes ◽  
C. Penney ◽  
S. Boyd ◽  
P. Daley
Keyword(s):  
Diagnostic Accuracy ◽  
Test Performance ◽  
Point Of Care ◽  
Risk Of Bias ◽  
Financial Impact ◽  
Test Accuracy ◽  
Respiratory Pathogens ◽  
Study Results ◽  
Group A ◽  
Point Of Care Tests

AbstractCommercial point-of-care (POC) diagnostic tests for Group A Streptococcus, Streptococcus pneumoniae, and influenza virus have large potential diagnostic and financial impact. Many published reports on test performance, often funded by diagnostics companies, are prone to bias. The Standards for Reporting of Diagnostic Accuracy (STARD 2015) are a protocol to encourage accurate, transparent reporting. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool evaluates risk of bias and transportability of results. We used these tools to evaluate diagnostic test accuracy studies of POC studies for three respiratory pathogens. For the 96 studies analysed, compliance was <25% for 14/34 STARD 2015 standards, and 3/7 QUADAS-2 domains showed a high risk of bias. All reports lacked reporting of at least one criterion. These biases should be considered in the interpretation of study results.

Unpacking the black box: Empirical evidence to understand the human factor for effective rapid testing against SARS-CoV2

2021 ◽  
Author(s):  
Cornelia Betsch ◽  
Philipp Sprengholz ◽  
Regina Siegers ◽  
Sarah Eitze ◽  
Lars Korn ◽  
...  
Keyword(s):  
Social Life ◽  
Point Of Care ◽  
Test Results ◽  
Rapid Testing ◽  
Infection Rates ◽  
Cross Sectional ◽  
Home Tests ◽  
Data Collections ◽  
Willingness To Use ◽  
Test Result

SARS-CoV-2 rapid antigen point-of-care (PoC) and home tests are available to laypeople. This raises questions regarding the drivers and barriers of people’s willingness to use tests, their understanding of test results and the psychological and behavioural consequences of positive and negative test results. Four cross-sectional data collections, including survey items, open text answers and three experiments, were therefore conducted between December 2020 and March 2021, involving 4,026 German participants. The majority was willing to use PoC or home tests. People will be more likely to use tests when they are inexpensive and easy to use or when they are a necessary (given low infection rates) for obtaining access to public and social life. However, people urgently need information about what a test result means and how they should behave. Recommendations based on the present findings could make rapid testing a successful pillar of pandemic management.

scholarly journals The diagnostic accuracy of isothermal nucleic acid point-of-care tests for human coronaviruses: A systematic review and meta-analysis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pakpoom Subsoontorn ◽  
Manupat Lohitnavy ◽  
Chuenjid Kongkaew
Keyword(s):  
Systematic Review ◽  
Diagnostic Accuracy ◽  
Diagnostic Test ◽  
Point Of Care ◽  
Meta Analysis ◽  
Isothermal Amplification ◽  
Diagnostic Test Accuracy ◽  
Test Accuracy ◽  
Index Test ◽  
Point Of Care Tests

AbstractMany recent studies reported coronavirus point-of-care tests (POCTs) based on isothermal amplification. However, the performances of these tests have not been systematically evaluated. Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy was used as a guideline for conducting this systematic review. We searched peer-reviewed and preprint articles in PubMed, BioRxiv and MedRxiv up to 28 September 2020 to identify studies that provide data to calculate sensitivity, specificity and diagnostic odds ratio (DOR). Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) was applied for assessing quality of included studies and Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) was followed for reporting. We included 81 studies from 65 research articles on POCTs of SARS, MERS and COVID-19. Most studies had high risk of patient selection and index test bias but low risk in other domains. Diagnostic specificities were high (> 0.95) for included studies while sensitivities varied depending on type of assays and sample used. Most studies (n = 51) used reverse transcription loop-mediated isothermal amplification (RT-LAMP) to diagnose coronaviruses. RT-LAMP of RNA purified from COVID-19 patient samples had pooled sensitivity at 0.94 (95% CI: 0.90–0.96). RT-LAMP of crude samples had substantially lower sensitivity at 0.78 (95% CI: 0.65–0.87). Abbott ID Now performance was similar to RT-LAMP of crude samples. Diagnostic performances by CRISPR and RT-LAMP on purified RNA were similar. Other diagnostic platforms including RT- recombinase assisted amplification (RT-RAA) and SAMBA-II also offered high sensitivity (> 0.95). Future studies should focus on the use of un-bias patient cohorts, double-blinded index test and detection assays that do not require RNA extraction.

scholarly journals Potential preanalytical and analytical vulnerabilities in the laboratory diagnosis of coronavirus disease 2019 (COVID-19)

2020 ◽  
Vol 58 (7) ◽  
pp. 1070-1076 ◽  
Author(s):  
Giuseppe Lippi ◽  
Ana-Maria Simundic ◽  
Mario Plebani
Keyword(s):  
Diagnostic Accuracy ◽  
Diagnostic Errors ◽  
Laboratory Diagnosis ◽  
Test Results ◽  
Rt Pcr ◽  
Viral Recombination ◽  
Technical Issues ◽  
Diagnostic Window ◽  
Novel Coronavirus ◽  
And Storage

AbstractA novel zoonotic coronavirus outbreak is spreading all over the world. This pandemic disease has now been defined as novel coronavirus disease 2019 (COVID-19), and is sustained by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As the current gold standard for the etiological diagnosis of SARS-CoV-2 infection is (real time) reverse transcription polymerase chain reaction (rRT-PCR) on respiratory tract specimens, the diagnostic accuracy of this technique shall be considered a foremost prerequisite. Overall, potential RT-PCR vulnerabilities include general preanalytical issues such as identification problems, inadequate procedures for collection, handling, transport and storage of the swabs, collection of inappropriate or inadequate material (for quality or volume), presence of interfering substances, manual errors, as well as specific aspects such as sample contamination and testing patients receiving antiretroviral therapy. Some analytical problems may also contribute to jeopardize the diagnostic accuracy, including testing outside the diagnostic window, active viral recombination, use of inadequately validated assays, insufficient harmonization, instrument malfunctioning, along with other specific technical issues. Some practical indications can hence be identified for minimizing the risk of diagnostic errors, encompassing the improvement of diagnostic accuracy by combining clinical evidence with results of chest computed tomography (CT) and RT-PCR, interpretation of RT-PCR results according to epidemiologic, clinical and radiological factors, recollection and testing of upper (or lower) respiratory specimens in patients with negative RT-PCR test results and high suspicion or probability of infection, dissemination of clear instructions for specimen (especially swab) collection, management and storage, together with refinement of molecular target(s) and thorough compliance with analytical procedures, including quality assurance.

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