Point-of-care tests for bovine clinical mastitis: what do we have and what do we need?

AbstractMastitis, inflammation of the bovine mammary gland, is generally caused by intramammary infection with bacteria, and antimicrobials have long been a corner stone of mastitis control. As societal concern about antimicrobial use in animal agriculture grows, there is pressure to reduce antimicrobial use in dairy farming. Point-of-care tests for on-farm use are increasingly available as tools to support this. In this Research Reflection, we consider available culture-dependent and culture-independent tests in the context of ASSURED criteria for low-resource settings, including convenience criteria, scientific criteria and societal criteria that can be used to evaluate test performance. As tests become more sophisticated and sensitive, we may be generating more data than we need. Special attention is given to the relationship between test outcomes and treatment decisions, including issues of diagnostic refinement, antimicrobial susceptibility testing, and detection of viable organisms. In addition, we explore the role of technology, big data and people in improved performance and uptake of point-of-care tests, recognising that societal barriers may limit uptake of available or future tests. Finally, we propose that the 3Rs of reduction, refinement and replacement, which have been used in an animal welfare context for many years, could be applied to antimicrobial use for mastitis control on dairy farms.

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Comparison of Four Commercially Available Point-of-Care Tests to Detect Antibodies against Canine Parvovirus in Dogs

Viruses ◽

10.3390/v13010018 ◽

2020 ◽

Vol 13 (1) ◽

pp. 18

Author(s):

Michèle Bergmann ◽

Mike Holzheu ◽

Yury Zablotski ◽

Stephanie Speck ◽

Uwe Truyen ◽

...

Keyword(s):

Test Performance ◽

Point Of Care ◽

Reference Method ◽

Canine Parvovirus ◽

P Value ◽

Important Indicator ◽

Specificity And Sensitivity ◽

Specific Pathogen ◽

The One ◽

Point Of Care Tests

Measuring antibodies to evaluate dogs´ immunity against canine parvovirus (CPV) is useful to avoid unnecessary re-vaccinations. The study aimed to evaluate the quality and practicability of four point-of-care (POC) tests for detection of anti-CPV antibodies. The sera of 198 client-owned and 43 specific pathogen-free (SPF) dogs were included; virus neutralization was the reference method. Specificity, sensitivity, positive and negative predictive value (PPV and NPV), and overall accuracy (OA) were calculated. Specificity was considered to be the most important indicator for POC test performance. Differences between specificity and sensitivity of POC tests in the sera of all dogs were determined by McNemar, agreement by Cohen´s kappa. Prevalence of anti-CPV antibodies in all dogs was 80% (192/241); in the subgroup of client-owned dogs, it was 97% (192/198); and in the subgroup of SPF dogs, it was 0% (0/43). FASTest® and CanTiCheck® were easiest to perform. Specificity was highest in the CanTiCheck® (overall dogs, 98%; client-owned dogs, 83%; SPF dogs, 100%) and the TiterCHEK® (overall dogs, 96%; client-owned dogs, 67%; SPF dogs, 100%); no significant differences in specificity were observed between the ImmunoComb®, the TiterCHEK®, and the CanTiCheck®. Sensitivity was highest in the FASTest® (overall dogs, 95%; client-owned dogs, 95%) and the CanTiCheck® (overall dogs, 80%; client-owned dogs, 80%); sensitivity of the FASTest® was significantly higher compared to the one of the other three tests (McNemars p-value in each comparison: <0.001). CanTiCheck® would be the POC test of choice when considering specificity and practicability. However, differences in the number of false positive results between CanTiCheck®, TiterCHEK®, and ImmunoComb® were minimal.

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

Epidemiology and Infection ◽

10.1017/s0950268818000596 ◽

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.

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Is There a Role of Using a Rapid Finger Prick Antibody Test in Screening for Celiac Disease in Children?

Gastroenterology Research and Practice ◽

10.1155/2019/4504679 ◽

2019 ◽

Vol 2019 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

Kristina Baraba Dekanić ◽

Ivona Butorac Ahel ◽

Lucija Ružman ◽

Jasmina Dolinšek ◽

Jernej Dolinšek ◽

...

Keyword(s):

Celiac Disease ◽

Point Of Care ◽

Tissue Transglutaminase ◽

Rapid Test ◽

Antibody Test ◽

First Grade ◽

Iga Deficiency ◽

Iga Antibodies ◽

Point Of Care Tests

Introduction. Celiac disease (CD) is an autoimmune disease triggered by gluten in genetically predisposed individuals. Despite the increasing prevalence of CD, many patients remain undiagnosed. Standard serology tests are expensive and invasive, so several point-of-care tests (POC) for CD have been developed. We aimed to determine the prevalence of CD in first-grade pupils in Primorje-Gorski Kotar County, Croatia, using a POC test. Methods. A Biocard celiac test that detects IgA antibodies to tissue transglutaminase in whole blood was used to screen for celiac disease in healthy first-grade children born in 2011 and 2012 who consumed gluten without restrictions. Results. 1478 children were tested, and none of them were tested positive with a rapid test. In 10 children (0,6%), IgA deficiency has been suspected; only 4 of them agreed to be tested further for total IgA, anti-tTG, and anti-DGP antibodies. IgA deficiency was confirmed in 3 patients, and in all 4 children, CD has been excluded. Conclusion. Our results have not confirmed the usefulness of the POC test in screening the general population of first-grade schoolchildren. Further research is needed to establish the true epidemiology of CD in Primorje-Gorski Kotar County and to confirm the value of the rapid test in comparison with standard antibody CD testing.

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Point-of-Care Tests for Bladder Cancer: The Influencing Role of Hematuria

Advances in Urology ◽

10.1155/2011/937561 ◽

2011 ◽

Vol 2011 ◽

pp. 1-5 ◽

Cited By ~ 12

Author(s):

Joerg Hennenlotter ◽

Severine Huber ◽

Tilman Todenhöfer ◽

Ursula Kuehs ◽

David Schilling ◽

...

Keyword(s):

Bladder Cancer ◽

Diagnostic Yield ◽

Point Of Care ◽

False Positives ◽

Two Systems ◽

Reliable Interpretation ◽

Point Of Care Tests ◽

The Impact

Introduction. Several point-of-care tests (POCT) are available for the diagnosis of bladder cancer (BC). We evaluate the impact of HU (hematuria) on performance of POCTs.Materials and Methods. Urine from 10 donors was diluted with blood from 0.5 to 0.00625%. BladderCheckR, BTAstatR, BCMR, and BTARtests were applied. Tests were additionally conducted in 54 patients with HU. HU was stratified according to the amount of erythrocytes (RBC)/μL using two systems: (1) no HU; mild microscopic HU; severe microscopic HU; gross HU; (2) I <25 RBCs; <250 II; ≥250 III. Results were compared to HU status and histopathology.Results. Gross HU became evident between 2090 RBCs/μL and 1065/μL. Addition of blood led to default tests in all 4: BladderCheckR0.25%; BCM 0.025%, BioNexia 0.00625%, and BTAstat <0.00625%. Rates of false positives for BladderCheck, BTAstat, BCM, and BioNexia were 5.9, 11.8, 0, and 1.8% without HU and 0, 66.7, 44.4, and 66.7% with HU. BTAstat, BCM, and BioNexia were independently influenced by HU (P<0.0002).Conclusions. NMP22-BladderCheck was most resistant to blood. The diagnostic yield of all others was significantly influenced by HU. A well-defined HU grading helps to define limits of HU for a reliable interpretation of BC-POCTs.

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Massive Hemorrhage: The Role of Whole Blood Viscoelastic Assays

Hämostaseologie ◽

10.1055/a-1227-8050 ◽

2020 ◽

Vol 40 (04) ◽

pp. 515-523

Author(s):

Emmanuelle Scala ◽

Carlo Marcucci

Keyword(s):

Whole Blood ◽

Point Of Care ◽

Turnaround Time ◽

Massive Hemorrhage ◽

Research Papers ◽

Treatment Algorithms ◽

Rotational Thromboelastometry ◽

The Subject ◽

Point Of Care Tests

AbstractViscoelastic whole blood tests are increasingly used to guide hemostatic therapy in bleeding patients in the perioperative, trauma, and obstetric settings. Compared with standard laboratory tests of hemostasis, they have a shorter turnaround time and provide simultaneous information on various aspects of clot formation and lysis. The two available brands TEG (thromboelastography) and ROTEM (rotational thromboelastometry) provide devices that are either manually operated or fully automated. The automation allows for the assays to be used as point-of-care tests increasing their usefulness in massively bleeding patients with rapidly changing hemostatic profiles. While the number of research papers on the subject and the number of published treatment algorithms increase rapidly, the influence of the use of these devices on patient outcome needs yet to be established. In this article, we first review the technology of these devices and the parameters provided by the assays. Next, we present the problems encountered when choosing cut-off values that trigger intervention. Furthermore, we discuss the studies examining their influence on clinical outcomes, and finally, we briefly highlight some of the most important limitations and pitfalls inherent to these assays.

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Point of care testing using rapid automated antigen testing for SARS-COV-2 in care homes – an exploratory safety, usability and diagnostic agreement evaluation

Journal of Patient Safety and Risk Management ◽

10.1177/25160435211054207 ◽

2021 ◽

pp. 251604352110542

Author(s):

Massimo Micocci ◽

Peter Buckle ◽

Gail Hayward ◽

A Joy Allen ◽

Kerrie Davies ◽

...

Keyword(s):

Test Performance ◽

Point Of Care ◽

Care Home ◽

Immunofluorescence Assay ◽

Careful Consideration ◽

Care Homes ◽

Performance Study ◽

Post Modification ◽

Point Of Care Tests ◽

Positive Agreement

Introduction Successful adoption of POCTs (Point-of-Care tests) for COVID-19 in care homes requires the identification of ideal use cases and a full understanding of the contextual and usability factors that affect test results and minimise biosafety risks. This paper presents a scoping-usability and test performance study of a microfluidic immunofluorescence assay for COVID-19 in care homes. Methods A mixed-methods evaluation was conducted in four UK care homes to scope usability and to assess the agreement with qRT-PCR. A dry run with luminescent dye was conducted to explore biosafety issues. Results The agreement analysis was conducted on 227 asymptomatic participants (159 staff and 68 residents) and 14 symptomatic participants (5 staff and 9 residents). Asymptomatic specimens showed 50% (95% CI:1.3%−98.7%) positive agreement and 96% (95% CI: 92.5%−98.1%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.911 (95% CI: 0.857−0.965). Symptomatic specimens showed 83.3% (95% CI: 35.9%−99.6%) positive agreement and 100% (95% CI: 63.1%−100%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.857 (95% CI: 0.549−1). The dry run highlighted four main sources of contamination that led to the modification of the standard operating procedures. Simulation post-modification showed no further evidence of contamination. Conclusion Careful consideration of biosafety issues and contextual factors associated with care home are mandatory for safe use the POCT. Whilst POCT may have some utility for ruling out COVID-19, further diagnostic accuracy evaluations are needed to promote effective adoption.

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DIAGNOSTIC STRATEGIES FOR ENDEMIC CORONAVIRUS DISEASE 2019 (COVID-19): RAPID ANTIGEN TESTS, REPEAT TESTING, AND PREVALENCE BOUNDARIES

Archives of Pathology & Laboratory Medicine ◽

10.5858/arpa.2021-0386-sa ◽

2021 ◽

Author(s):

Gerald J. Kost

Keyword(s):

Test Performance ◽

Point Of Care ◽

Low Cost ◽

Herd Immunity ◽

Repeated Testing ◽

Predictive Values ◽

Diagnostic Strategies ◽

Performance Patterns ◽

Improved Performance ◽

Antigen Tests

Abstract Context. – Coronavirus disease 2019 (COVID-19) rapid antigen tests generate intrinsically fast, inherently spatial, and immediately actionable results. They quickly confirm COVID-19, but weakly rule out infection. Test performance depends on prevalence and testing protocol. Both affect predictive values. Objectives. – To use original mathematics and visual logistics for interpreting COVID-19 rapid antigen test performance patterns, gauge the influence of prevalence, and evaluate repeated testing. Design. – Mathematica and open access software helped graph relationships, perform recursive computations, and compare performance patterns. PubMed retrieved articles addressing endemic COVID-19. Results. – Tiered sensitivity/specificity comprise: T1) 90%/95%; T2) 95%/97.5%; and T3) 100%/≥99%, respectively. Performance of self- and home antigen tests with Food and Drug Administration Emergency Use Authorization peaks in low prevalence. Fall-off in performance appears with increasing prevalence because suboptimal sensitivity creates false negatives. The rate of false omissions limits clinical use because of prevalence boundaries based on tolerance for risk. Mathematical analysis supports testing twice to improve predictive values and extend prevalence boundaries nearly to levels of herd immunity. Conclusions. – COVID-19 is quickly becoming endemic. Suboptimal sensitivity of rapid antigen tests limits performance in high prevalence. Risk of contagion in packed spaces (e.g., airplanes) might be avoided with dual testing 36 hours apart, allowing time for viral load to increase. Awareness of community prevalence and proof of improved performance with repeated testing will help manage COVID-19 risk, while meeting rapid decision-making needs for highly contagious and new variants (e.g., Delta). New COVID-19 variants call for high quality, low cost, readily accessible, fast, user friendly, and ubiquitous point-of-care testing.

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Point of Care Testing using rapid automated Antigen Testing for SARS-COV-2 in Care Homes – an exploratory safety, usability and diagnostic agreement evaluation

10.1101/2021.04.22.21255948 ◽

2021 ◽

Author(s):

Massimo Micocci ◽

Peter Buckle ◽

Gail Hayward ◽

A. Joy Allen ◽

Kerrie Davies ◽

...

Keyword(s):

Test Performance ◽

Point Of Care ◽

Care Home ◽

Immunofluorescence Assay ◽

Careful Consideration ◽

Care Homes ◽

Performance Study ◽

Mixed Methods Evaluation ◽

Point Of Care Tests ◽

Positive Agreement

AbstractIntroductionSuccessful adoption of POCTs (Point-of-Care tests) for COVID-19 in care homes requires the identification of ideal use cases and a full understanding of contextual and usability factors that affect test results and minimise biosafety risks. This paper presents findings from a scoping-usability and test performance study of a microfluidic immunofluorescence assay for COVID-19 in care homes.MethodsA mixed-methods evaluation was conducted in four UK care homes to scope usability and to assess the agreement with qRT-PCR. A dry run with luminescent dye was carried out to explore biosafety issues.ResultsThe agreement analysis was carried out on 227 asymptomatic participants (159 staff and 68 residents) and 14 symptomatic participants (5 staff and 9 residents). Asymptomatic specimens showed 50% (95% CI: 1.3%-98.7%) positive agreement and 96% (95% CI: 92.5%-98.1%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.911 (95% CI: 0.857-0.965). Symptomatic specimens showed 83.3% (95% CI: 35.9%-99.6%) positive agreement and 100% (95% CI: 63.1%-100%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.857 (95% CI: 0.549-1).The dry run showed four main sources of contamination that led to the modification of the standard operating procedures. Simulation after modification showed no further evidence of contamination.ConclusionCareful consideration of biosafety issues and contextual factors associated with care home are mandatory for safe use the POCT. Whilst POCT may have some utility for ruling out COVID-19, further diagnostic accuracy evaluations are needed to promote effective adoption.

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