scholarly journals Evaluation of serological lateral flow assays for severe acute respiratory syndrome coronavirus-2

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Bianca A. Trombetta ◽  
Savannah E. Kandigian ◽  
Robert R. Kitchen ◽  
Korneel Grauwet ◽  
Pia Kivisäkk Webb ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Limit Of Detection ◽  
Lateral Flow ◽  
Test Accuracy ◽  
Predictive Values ◽  
Public Resource ◽  
Attractive Option ◽  
Lateral Flow Assays ◽  
The Cost ◽  
The Impact

Abstract Background COVID-19 has resulted in significant morbidity and mortality worldwide. Lateral flow assays can detect anti-Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) antibodies to monitor transmission. However, standardized evaluation of their accuracy and tools to aid in interpreting results are needed. Methods We evaluated 20 IgG and IgM assays selected from available tests in April 2020. We evaluated the assays’ performance using 56 pre-pandemic negative and 56 SARS-CoV-2-positive plasma samples, collected 10–40 days after symptom onset, confirmed by a molecular test and analyzed by an ultra-sensitive immunoassay. Finally, we developed a user-friendly web app to extrapolate the positive predictive values based on their accuracy and local prevalence. Results Combined IgG + IgM sensitivities ranged from 33.9 to 94.6%, while combined specificities ranged from 92.6 to 100%. The highest sensitivities were detected in Lumiquick for IgG (98.2%), BioHit for both IgM (96.4%), and combined IgG + IgM sensitivity (94.6%). Furthermore, 11 LFAs and 8 LFAs showed perfect specificity for IgG and IgM, respectively, with 15 LFAs showing perfect combined IgG + IgM specificity. Lumiquick had the lowest estimated limit-of-detection (LOD) (0.1 μg/mL), followed by a similar LOD of 1.5 μg/mL for CareHealth, Cellex, KHB, and Vivachek. Conclusion We provide a public resource of the accuracy of select lateral flow assays with potential for home testing. The cost-effectiveness, scalable manufacturing process, and suitability for self-testing makes LFAs an attractive option for monitoring disease prevalence and assessing vaccine responsiveness. Our web tool provides an easy-to-use interface to demonstrate the impact of prevalence and test accuracy on the positive predictive values.

scholarly journals Evaluation of serological lateral flow assays for severe acute respiratory syndrome coronavirus-2

2021 ◽  
Author(s):  
Bianca A. Trombetta ◽  
Savannah E. Kandigian ◽  
Robert R. Kitchen ◽  
Korneel Grauwet ◽  
Pia Kivisäkk Webb ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Limit Of Detection ◽  
Lateral Flow ◽  
Test Accuracy ◽  
Predictive Values ◽  
Public Resource ◽  
Attractive Option ◽  
Lateral Flow Assays ◽  
The Cost ◽  
The Impact

Abstract Background: COVID-19 has resulted in significant morbidity and mortality worldwide. Lateral flow assays can detect anti-Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) antibodies to monitor transmission. However, standardized evaluation of their accuracy and tools to aid in interpreting results are needed.Methods: We evaluated 20 IgG and IgM assays selected from available tests in April 2020. We evaluated the assays’ performance using 56 pre-pandemic negative and 56 SARS-CoV-2-positive plasma samples, collected 10-40 days after symptom onset, confirmed by a molecular test and analyzed by an ultra-sensitive immunoassay. Finally, we developed a user-friendly web app to extrapolate the positive predictive values based on their accuracy and local prevalence.Results: Combined IgG+IgM sensitivities ranged from 33.9% to 94.6%, while combined specificities ranged from 92.6% to 100%. The highest sensitivities were detected in Lumiquick for IgG (98.2%), BioHit for both IgM (96.4%), and combined IgG+IgM sensitivity (94.6%). Furthermore, 11 LFAs and 8 LFAs showed perfect specificity for IgG and IgM, respectively, with 15 LFAs showing perfect combined IgG+IgM specificity. Lumiquick had the lowest estimated limit-of-detection (LOD) (0.1 mg/mL), followed by a similar LOD of 1.5 mg/mL for CareHealth, Cellex, KHB, and Vivachek.Conclusion: We provide a public resource of the accuracy of select lateral flow assays with potential for home testing. The cost-effectiveness, scalable manufacturing process, and suitability for self-testing makes LFAs an attractive option for monitoring disease prevalence and assessing vaccine responsiveness. Our web tool provides an easy-to-use interface to demonstrate the impact of prevalence and test accuracy on the positive predictive values.

scholarly journals Evaluation of serological lateral flow assays for severe acute respiratory syndrome coronavirus-2

2021 ◽  
Author(s):  
Bianca A. Trombetta ◽  
Savannah E. Kandigian ◽  
Robert R. Kitchen ◽  
Korneel Grauwet ◽  
Pia Kivisäkk Webb ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Limit Of Detection ◽  
Lateral Flow ◽  
Test Accuracy ◽  
Predictive Values ◽  
Public Resource ◽  
Attractive Option ◽  
Lateral Flow Assays ◽  
The Cost ◽  
The Impact

AbstractBackgroundCOVID-19 has resulted in significant morbidity and mortality worldwide. Lateral flow assays can detect anti-Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) antibodies to monitor transmission. However, standardized evaluation of their accuracy and tools to aid in interpreting results are needed.MethodsWe evaluated 20 IgG and IgM assays selected from available tests in April 2020. We evaluated the assays’ performance using 56 pre-pandemic negative and 56 SARS-CoV-2-positive plasma samples, collected 10-40 days after symptom onset, confirmed by a molecular test and analyzed by an ultra-sensitive immunoassay. Finally, we developed a user-friendly web app to extrapolate the positive predictive values based on their accuracy and local prevalence.ResultsCombined IgG+IgM sensitivities ranged from 33.9% to 94.6%, while combined specificities ranged from 92.6% to 100%. The highest sensitivities were detected in Lumiquick for IgG (98.2%), BioHit for both IgM (96.4%), and combined IgG+IgM sensitivity (94.6%). Furthermore, 11 LFAs and 8 LFAs showed perfect specificity for IgG and IgM, respectively, with 15 LFAs showing perfect combined IgG+IgM specificity. Lumiquick had the lowest estimated limit-of-detection (LOD) (0.1 μg/mL), followed by a similar LOD of 1.5 μg/mL for CareHealth, Cellex, KHB, and Vivachek.ConclusionWe provide a public resource of the accuracy of select lateral flow assays with potential for home testing. The cost-effectiveness, scalable manufacturing process, and suitability for self-testing makes LFAs an attractive option for monitoring disease prevalence and assessing vaccine responsiveness. Our web tool provides an easy-to-use interface to demonstrate the impact of prevalence and test accuracy on the positive predictive values.

scholarly journals Design of Multiplex Lateral Flow Tests: A Case Study for Simultaneous Detection of Three Antibiotics

Biosensors ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 17 ◽  
Author(s):  
Anastasiya V. Bartosh ◽  
Dmitriy V. Sotnikov ◽  
Olga D. Hendrickson ◽  
Anatoly V. Zherdev ◽  
Boris B. Dzantiev
Keyword(s):  
Limit Of Detection ◽  
Simultaneous Detection ◽  
Optimal Location ◽  
Lateral Flow ◽  
Immunochromatographic Test ◽  
Equilibrium Conditions ◽  
Lateral Flow Assays ◽  
Lateral Flow Tests ◽  
The Impact

The presented study is focused on the impact of binding zone location on immunochromatographic test strips on the analytical parameters of multiplex lateral flow assays. Due to non-equilibrium conditions for such assays the duration of immune reactions influences significantly the analytical parameters, and the integration of several analytes into one multiplex strip may cause an essential decrease of sensitivity. To choose the best location for binding zones, we have tested reactants for immunochromatographic assays of lincomycin, chloramphenicol, and tetracycline. The influence of the distance to the binding zones on the intensity of coloration and limit of detection (LOD) was rather different. Basing on the data obtained, the best order of binding zones was chosen. In comparison with non-optimal location the LODs were 5–10 fold improved. The final assay provides LODs 0.4, 0.4 and 1.0 ng/mL for lincomycin, chloramphenicol, and tetracycline, respectively. The proposed approach can be applied for multiplexed assays of other analytes.

Development of a Smartphone Based Reader for the Quantitative Analysis of Lateral Flow Assays

2018 ◽  
Vol 941 ◽  
pp. 2522-2527
Author(s):  
Sylvio Schneider ◽  
Martina Selig ◽  
Verena Keil ◽  
Matthias Lehmann ◽  
Andreas H. Foitzik ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Medical Devices ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Thrombotic Event ◽  
Lateral Flow ◽  
Proof Of Concept ◽  
Lateral Flow Assays ◽  
Further Development ◽  
D Dimer

Smartphones are developing into all-purposes devices. In the present work, the employment/application of smartphones as medical devices in home care and point-of-care (POC) diagnostics are investigated in the analysis of Lateral Flow Assays (LFA). A smartphone-based LFA reader was developed for the quantitative analysis of D-Dimer – a biomarker indicating e.g. thrombotic event or danger of embolism.The proof-of-concept has been shown with multiple smartphones in establishing: (I) Optimal dimensions of the LFA cell of 72.11mm distance of smartphone to D-Dimer test leading to a coefficients of variances (CV) between 0.8% and 4.2%. (II) Inter-device investigations: CVs around 13.5%; a limit of detection (LOD) of 100ng/ml (DDU) D-Dimer. (III) Inter-smartphone investigations: CV about 16%, a limit of detection (LOD) at 66.4ng/ml (DDU). (IV) Calibrations: CV and LOD of three smartphones are comparable to the commercial available LFA reader. Further development to put the multiple smartphone-based LFA reader on the market.

scholarly journals Next level proctored exam for proficiency testing in Primary Care Education: an observatory study on efficiency and accuracy and on exam outcome. (Preprint)

2020 ◽  
Author(s):  
Birgitte Schoenmakers ◽  
Johan Wens
Keyword(s):  
Background Noise ◽  
Negative Impact ◽  
Cost Benefit ◽  
Critical Event ◽  
Future Research ◽  
Test Accuracy ◽  
Primary Care Education ◽  
Technical Issues ◽  
The Cost ◽  
The Impact

BACKGROUND The COVID19 pandemic affected education and assessment and led to a complex planning. Therefore, we organised the proficiency test for admission to Family Medicine as a proctored exam. To prevent from fraud we developed a virtual supervisor app tracking and tracing candidates’ behaviour. OBJECTIVE To assess efficiency and accuracy of the proctored exam procedure and to test the impact on the exam scores. METHODS The app operates on three levels to register events: recording of actions, analyses of behaviour and live supervision. Each suspicious event is given a score. To assess efficiency we inventoried the technical issues and the interventions. To test accuracy we counted the number of suspicious students and behaviours. To test the impact of the supervising app on students’ exam outcome we compared the scores between the proctored and the on campus group. Candidates were free to register for off or on campus participation. RESULTS 593 candidates subscribed to the exam: 472 (79%) candidates used the supervisor app and 121 (20%) were on campus. Test results of both groups were comparable. We registered 15 technical issues in off campus context. Two candidates experienced a negative impact on the exam due to the technical issue. The app detected 22 candidates with a suspicious level >1, mainly increased due to background noise. All events occurred without fraud purpose. CONCLUSIONS This pilot study demonstrated that a supervisor app with recording and registration behaviour is able to detect suspicious events without an impact on the exam. Background noise was the most critical event. There was no fraud detected. A supervisor app registering and recording behaviour to prevent from fraud during exams is efficient and not affecting the exam outcome. In future research, a controlled design should compare the cost-benefit balance between the complex intervention of the supervisor app and the combination of the candidates’ awareness of being monitored with a safe exam browsing plug in. CLINICALTRIAL Not applicable

Time to Clinical Response: An Outcome of Antibiotic Therapy of Febrile Neutropenia With Implications for Quality and Cost of Care

2000 ◽  
Vol 18 (21) ◽  
pp. 3699-3706 ◽  
Author(s):  
Linda S. Elting ◽  
Edward B. Rubenstein ◽  
Kenneth Rolston ◽  
Scott B. Cantor ◽  
Charles G. Martin ◽  
...  
Keyword(s):  
Febrile Neutropenia ◽  
Antibiotic Therapy ◽  
Clinical Response ◽  
Median Time ◽  
Early Discharge ◽  
Cost Of Care ◽  
Predictive Values ◽  
The Cost ◽  
The Impact ◽  
Time Point

PURPOSE: To determine whether antibiotic regimens with similar rates of response differ significantly in the speed of response and to estimate the impact of this difference on the cost of febrile neutropenia. METHODS: The time point of clinical response was defined by comparing the sensitivity, specificity, and predictive values of alternative objective and subjective definitions. Data from 488 episodes of febrile neutropenia, treated with either of two commonly used antibiotics (coded A or B) during six clinical trials, were pooled to compare the median time to clinical response, days of antibiotic therapy and hospitalization, and estimated costs. RESULTS: Response rates were similar; however, the median time to clinical response was significantly shorter with A-based regimens (5 days) compared with B-based regimens (7 days; P = .003). After 72 hours of therapy, 33% of patients who received A but only 18% of those who received B had responded (P = .01). These differences resulted in fewer days of antibiotic therapy and hospitalization with A-based regimens (7 and 9 days) compared with B-based regimens (9 and 12 days, respectively; P < .04) and in significantly lower estimated median costs ($8,491 v $11,133 per episode; P = .03). Early discharge at the time of clinical response should reduce the median cost from $10,752 to $8,162 (P < .001). CONCLUSION: Despite virtually identical rates of response, time to clinical response and estimated cost of care varied significantly among regimens. An early discharge strategy based on our definition of the time point of clinical response may further reduce the cost of treating non–low-risk patients with febrile neutropenia.

scholarly journals Correction to: Evaluation of serological lateral flow assays for severe acute respiratory syndrome coronavirus-2

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Bianca A. Trombetta ◽  
Savannah E. Kandigian ◽  
Robert R. Kitchen ◽  
Korneel Grauwet ◽  
Pia Kivisäkk Webb ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Lateral Flow ◽  
Lateral Flow Assays

scholarly journals Design of Multiplex Lateral Flow Tests: A Case Study for Simultaneous Detection of Three Antibiotics

2019 ◽  
Author(s):  
Anastasiya V. Bartosh ◽  
Dmitriy V. Sotnikov ◽  
Olga D. Hendrickson ◽  
Anatoly V. Zherdev ◽  
Boris B. Dzantiev
Keyword(s):  
Limit Of Detection ◽  
Simultaneous Detection ◽  
Optimal Location ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Immunochromatographic Test ◽  
Equilibrium Conditions ◽  
Lateral Flow Tests ◽  
The Impact

The presented study is focused on the impact of binding zones locations at immunochromatographic test strips into analytical parameters of multiplex lateral flow assay. Due to non-equilibrium conditions for such assays the duration of immune reactions influences significantly on analytical parameters, and the integration of several analytes into one multiplex strip may cause essential decrease of sensitivity. To choose the best location of binding zones, we have tested reactants for immunochromatographic assays of lincomycin, chloramphenicol, and tetracycline. The influence of the distance to the binding zones on the intensity of coloration and limit of detection (LOD) was rather different. Basing on the obtained data, the best order of binding zones was chosen. In comparison with non-optimal location the LODs were 5-10 fold improved. The final assay provides LODs 0.4, 0.4 and 1.0 ng/mL for lincomycin, chloramphenicol, and tetracycline, respectively. The proposed approach can be applied for multiassays of other analytes.

scholarly journals Monoclonal Antibodies Application in Lateral Flow Immunochromatographic Assays for Drugs of Abuse Detection

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1058
Author(s):  
Zidane Qriouet ◽  
Yahia Cherrah ◽  
Hassan Sefrioui ◽  
Zineb Qmichou
Keyword(s):  
High Performance ◽  
Drugs Of Abuse ◽  
Limit Of Detection ◽  
Lateral Flow ◽  
Detection Sensitivity ◽  
Gas Chromatography Mass Spectrometry ◽  
Resource Limited ◽  
Short Period ◽  
Reaction Gas Chromatography ◽  
Lateral Flow Assays

Lateral flow assays (lateral flow immunoassays and nucleic acid lateral flow assays) have experienced a great boom in a wide variety of early diagnostic and screening applications. As opposed to conventional examinations (High Performance Liquid Chromatography, Polymerase Chain Reaction, Gas chromatography-Mass Spectrometry, etc.), they obtain the results of a sample’s analysis within a short period. In resource-limited areas, these tests must be simple, reliable, and inexpensive. In this review, we outline the production process of antibodies against drugs of abuse (such as heroin, amphetamine, benzodiazepines, cannabis, etc.), used in lateral flow immunoassays as revelation or detection molecules, with a focus on the components, the principles, the formats, and the mechanisms of reaction of these assays. Further, we report the monoclonal antibody advantages over the polyclonal ones used against drugs of abuse. The perspective on aptamer use for lateral flow assay development was also discussed as a possible alternative to antibodies in view of improving the limit of detection, sensitivity, and specificity of lateral flow assays.

scholarly journals A systematic review and economic evaluation of diagnostic strategies for Lynch syndrome

2014 ◽  
Vol 18 (58) ◽  
pp. 1-406 ◽  
Author(s):  
Tristan Snowsill ◽  
Nicola Huxley ◽  
Martin Hoyle ◽  
Tracey Jones-Hughes ◽  
Helen Coelho ◽  
...  
Keyword(s):  
Cost Effectiveness ◽  
De Novo ◽  
Health Benefit ◽  
Cost Effective ◽  
Test Accuracy ◽  
Newly Diagnosed ◽  
Diagnostic Strategies ◽  
Age Limit ◽  
The Cost ◽  
The Impact

BackgroundLynch syndrome (LS) is an inherited autosomal dominant disorder characterised by an increased risk of colorectal cancer (CRC) and other cancers, and caused by mutations in the deoxyribonucleic acid (DNA) mismatch repair genes.ObjectiveTo evaluate the accuracy and cost-effectiveness of strategies to identify LS in newly diagnosed early-onset CRC patients (aged < 50 years). Cascade testing of relatives is employed in all strategies for individuals in whom LS is identified.Data sources and methodsSystematic reviews were conducted of the test accuracy of microsatellite instability (MSI) testing or immunohistochemistry (IHC) in individuals with CRC at risk of LS, and of economic evidence relating to diagnostic strategies for LS. Reviews were carried out in April 2012 (test accuracy); and in February 2012, repeated in February 2013 (economic evaluations). Databases searched included MEDLINE (1946 to April week 3, 2012), EMBASE (1980 to week 17, 2012) and Web of Science (inception to 30 April 2012), and risk of bias for test accuracy was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) quality appraisal tool. A de novo economic model of diagnostic strategies for LS was developed.ResultsInconsistencies in study designs precluded pooling of diagnostic test accuracy results from a previous systematic review and nine subsequent primary studies. These were of mixed quality, with significant methodological concerns identified for most. IHC and MSI can both play a part in diagnosing LS but neither is gold standard. No UK studies evaluated the cost-effectiveness of diagnosing and managing LS, although studies from other countries generally found some strategies to be cost-effective compared with no testing.The de novo model demonstrated that all strategies were cost-effective compared with no testing at a threshold of £20,000 per quality-adjusted life-year (QALY), with the most cost-effective strategy utilising MSI andBRAFtesting [incremental cost-effectiveness ratio (ICER) = £5491 per QALY]. The maximum health benefit to the population of interest would be obtained using universal germline testing, but this would not be a cost-effective use of NHS resources compared with the next best strategy. When the age limit was raised from 50 to 60 and 70 years, the ICERs compared with no testing increased but remained below £20,000 per QALY (except for universal germline testing with an age limit of 70 years). The total net health benefit increased with the age limit as more individuals with LS were identified. Uncertainty was evaluated through univariate sensitivity analyses, which suggested that the parameters substantially affecting cost-effectiveness: were the risk of CRC for individuals with LS; the average number of relatives identified per index patient; the effectiveness of colonoscopy in preventing metachronous CRC; the cost of colonoscopy; the duration of the psychological impact of genetic testing on health-related quality of life (HRQoL); and the impact of prophylactic hysterectomy and bilateral salpingo-oophorectomy on HRQoL (this had the potential to make all testing strategies more expensive and less effective than no testing).LimitationsThe absence of high-quality data for the impact of prophylactic gynaecological surgery and the psychological impact of genetic testing on HRQoL is an acknowledged limitation.ConclusionsResults suggest that reflex testing for LS in newly diagnosed CRC patients aged < 50 years is cost-effective. Such testing may also be cost-effective in newly diagnosed CRC patients aged < 60 or < 70 years. Results are subject to uncertainty due to a number of parameters, for some of which good estimates were not identified. We recommend future research to estimate the cost-effectiveness of testing for LS in individuals with newly diagnosed endometrial or ovarian cancer, and the inclusion of aspirin chemoprevention. Further research is required to accurately estimate the impact of interventions on HRQoL.Study registrationThis study is registered as PROSPERO CRD42012002436.FundingThe National Institute for Health Research Health Technology Assessment programme.

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