scholarly journals Evaluation of the practicability of a finger-stick whole-blood SARS-Cov-2 self-test adapted for the general population

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245848
Author(s):  
Thierry Prazuck ◽  
Jean Phan Van ◽  
Florence Sinturel ◽  
Frederique Levray ◽  
Allan Elie ◽  
...  
Keyword(s):  
General Population ◽  
Whole Blood ◽  
Point Of Care ◽  
Real Life ◽  
High Sensitivity ◽  
University Hospital ◽  
Life Study ◽  
Self Test ◽  
Finger Stick ◽  
Instructions For Use

Background COVID-19 (COronaVIrus Disease 2019) is an infectious respiratory disease caused by the novel SARS-CoV-2 virus. Point of Care (POC) tests have been developed to detect specific antibodies, IgG and IgM, to SARS-CoV-2 virus in human whole blood. They need to be easily usable by the general population in order to alleviate the lockdown that many countries have initiated in response to the growing COVID-19 pandemic. A real-life study has been conducted in order to evaluate the performance of the COVID-PRESTO® POC test and the results were recently published. Even if this test showed very high sensitivity and specificity in a laboratory setting when used by trained professionals, it needs to be further evaluated for practicability when used by the general public in order to be approved by health authorities for in-home use. Methods 143 participants were recruited between March 2020 and April 2020 among non-medical populations in central France (nuclear plant workers, individuals attending the Orleans University Hospital vaccination clinic and Orleans University Hospital non-medical staff). Instructions for use, with or without a tutorial video, were made available to the volunteers. Two separate objectives were pursued: evaluation of the capability of participants to obtain an interpretable result, and evaluation of the users’ ability to read the results. Results 88.4% of the test users judged the instructions for use leaflet to be clear and understandable. 99.3% of the users obtained a valid result and, according to the supervisors, 92.7% of the tests were properly performed by the users. Overall, 95% of the users gave positive feedback on the COVID PRESTO® as a potential self-test. Neither age nor education had an influence. Conclusion COVID-PRESTO® was successfully used by an overwhelming majority of participants and its use was judged very satisfactory, therefore showing promising potential as a self-test to be used by the general population. This POC test can become an easy-to-use tool to help detect whether individuals are protected or not, particularly in the context of a second wave or a mass vaccination program.

scholarly journals Evaluation of the Practicability of a Finger-Stick Whole-Blood SARS-Cov-2 Self-Test Adapted for the General Population.

2020 ◽  
Author(s):  
thierry prazuck ◽  
Jean Phan Van ◽  
Florence sinturel ◽  
frederique levray ◽  
Allan Elie ◽  
...  
Keyword(s):  
General Population ◽  
Whole Blood ◽  
Real Life ◽  
High Sensitivity ◽  
University Hospital ◽  
Life Study ◽  
Health Authorities ◽  
Self Test ◽  
Finger Stick ◽  
Instructions For Use

Background COVID-19 (COronaVIrus Disease 2019) is an infectious respiratory disease caused by the novel SARS-CoV-2 virus. Rapid Diagnostic Tests (RDTs) have been developed to detect specific antibodies, IgG and IgM, to SARS-CoV-2 virus in human whole blood and easily usable by the general population are needed in order to alleviate the lockdown that many countries have initiated in response to the growing COVID-19 pandemic. A real-life study has been conducted in order to evaluate the performance of the COVID-PRESTO RDT and the results have been submitted for publication and are currently under review. Even if this test showed very high sensitivity and specificity in a laboratory setting when used by trained professionals, it needs to be further evaluated for practicability when used by common folk in order to be approved by health authorities for in-home use Methods 142 participants were recruited between March 2020 and April 2020 among non-medical populations in central France (nuclear plants workers, individuals attending the Orleans University Hospital vaccination clinic and Orleans University Hospital non-medical staff). Instructions for use with or without a tutorial video was made available to the volunteers. Two separate objectives were pursued: evaluation of the capability of participants to obtain an interpretable result, and evaluation of the users ability to read the results. Results 88.4 % of the test users judged the instruction for use leaflet to be clear and understandable. 99.3 % of the users obtained a valid results and according to the supervisors 92.7% of the tests were properly performed by the user. Overall, 95% of the users gave positive feedback toward the COVID PRESTO as a potential self-test. No influence of age and education was observed. Conclusion COVID-PRESTO was successfully used by an overwhelming majority of participants and its utilization was judged very satisfactory, therefore showing a promising potential as a self-test to be used by the general population. This RDT can become an easy-to-use tool to help know whether individuals are protected or not, particularly in the perspective of a second wave or a mass vaccination program.

scholarly journals Evaluation of performance of two SARS-CoV-2 Rapid whole-blood finger-stick IgM-IgG Combined Antibody Tests

2020 ◽  
Author(s):  
Thierry Prazuck ◽  
Mathilda Colin ◽  
Susanna Giachè ◽  
Camélia Gubavu ◽  
Aymeric Seve ◽  
...  
Keyword(s):  
Whole Blood ◽  
Real Life ◽  
Rapid Test ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Life Study ◽  
Negative Results ◽  
Specificity And Sensitivity ◽  
Capillary Blood Sample ◽  
Finger Stick

AbstractBackgroundThe SARS-CoV-2 virus is responsible for the infectious respiratory disease called COVID-19 (COronaVIrus Disease). In response to the growing COVID-19 pandemic, Rapid Diagnostic Tests (RDTs) have been developed to detect specific antibodies, IgG and IgM, to SARS-CoV-2 virus in human whole blood. We conducted a real-life study to evaluate the performance of two RDTs, COVID-PRESTO® and COVID-DUO®, compared to the gold standard, RT-PCR.MethodsRT-PCR testing of SARS-Cov-2 was performed from nasopharyngeal swab specimens collected in adult patients visiting the infectious disease department at the hospital (Orléans, France). Fingertip whole blood samples taken at different time points after onset of the disease were tested with RDTs. The specificity and sensitivity of the rapid test kits compared to test of reference (RT-PCR) were calculated.ResultsAmong 381 patients with symptoms of COVID-19 who went to the hospital for a diagnostic, 143 patients were RT-PCR negative. Results of test with RDTs were all negative for these patients, indicating a specificity of 100% for both RDTs.In the RT-PCR positive subgroup (n=238), 133 patients were tested with COVID-PRESTO® and 129 patients were tested with COVID-DUO® (24 patients tested with both). The further the onset of symptoms was from the date of collection, the greater the sensitivity. The sensitivity of COVID-PRESTO® test ranged from 10.00% for patients having experienced their 1st symptoms from 0 to 5 days ago to 100% in patients where symptoms had occurred more than 15 days before the date of tests. For COVID-DUO® test, the sensitivity ranged from 35.71% [0-5 days] to 100% (> 15 days).ConclusionCOVID-PRESTO® and DUO® RDTs turned out to be very specific (none false positive) and to be sensitive enough after 15 days from onset of symptom. These easy to use IgG/IgM combined test kits are the first ones allowing a screening with capillary blood sample, by typing from a finger prick. These rapid tests are particularly interesting for screening in low resource settings.

Development of a point-of-care assay system for high-sensitivity C-reactive protein in whole blood

2003 ◽  
Vol 332 (1-2) ◽  
pp. 51-59 ◽  
Author(s):  
Jae Soon Ahn ◽  
Sunga Choi ◽  
Sang Ho Jang ◽  
Hyuk Jae Chang ◽  
Jae Hoon Kim ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
High Sensitivity ◽  
Assay System ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Point Of Care Assay

scholarly journals Monitoring DOACs with a Novel Dielectric Microsensor: A Clinical Study

2020 ◽  
Author(s):  
Debnath Maji ◽  
Aman Opneja ◽  
Michael A. Suster ◽  
Kara L. Bane ◽  
Brigid M. Wilson ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Oral Anticoagulants ◽  
Characteristic Curve ◽  
Direct Oral Anticoagulants ◽  
Unmet Need ◽  
Area Under The Curve ◽  
High Sensitivity ◽  
Diagnostic Study ◽  
Coagulation Tests

Abstract Background There are acute settings where assessing the anticoagulant effect of direct oral anticoagulants (DOACs) can be useful. Due to variability among routine coagulation tests, there is an unmet need for an assay that detects DOAC effects within minutes in the laboratory or at the point of care. Methods We developed a novel dielectric microsensor, termed ClotChip, and previously showed that the time to reach peak permittivity (T peak) is a sensitive parameter of coagulation function. We conducted a prospective, single-center, pilot study to determine its clinical utility at detecting DOAC anticoagulant effects in whole blood. Results We accrued 154 individuals: 50 healthy volunteers, 49 rivaroxaban patients, 47 apixaban, and 8 dabigatran patients. Blood samples underwent ClotChip measurements and plasma coagulation tests. Control mean T peak was 428 seconds (95% confidence interval [CI]: 401–455 seconds). For rivaroxaban, mean T peak was 592 seconds (95% CI: 550–634 seconds). A receiver operating characteristic curve showed that the area under the curve (AUC) predicting rivaroxaban using T peak was 0.83 (95% CI: 0.75–0.91, p < 0.01). For apixaban, mean T peak was 594 seconds (95% CI: 548–639 seconds); AUC was 0.82 (95% CI: 0.73–0.91, p < 0.01). For dabigatran, mean T peak was 894 seconds (95% CI: 701–1,086 seconds); AUC was 1 (p < 0.01). Specificity for all DOACs was 88%; sensitivity ranged from 72 to 100%. Conclusion This diagnostic study using samples from “real-world” DOAC patients supports that ClotChip exhibits high sensitivity at detecting DOAC anticoagulant effects in a disposable portable platform, using a miniscule amount of whole blood (<10 µL).

scholarly journals Ultrarapid, Ultrasensitive One-Step Kinetic Immunoassay for C-Reactive Protein (CRP) in Whole Blood Samples: Measurement of the Entire CRP Concentration Range with a Single Sample Dilution

2002 ◽  
Vol 48 (2) ◽  
pp. 269-277 ◽  
Author(s):  
Piia Tarkkinen ◽  
Tom Palenius ◽  
Timo Lövgren
Keyword(s):  
Whole Blood ◽  
Solid Phase ◽  
Point Of Care ◽  
High Sensitivity ◽  
Clinical Samples ◽  
Cardiac Complications ◽  
Fluorescence Signal ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
One Step

Abstract Background: Recently, measurement of very low concentrations of C-reactive protein (CRP) has gained popularity as a potential new means for predicting the risk of future cardiac complications. In this study, we demonstrate the feasibility of a kinetic, one-step microparticle assay for quantitative determination of extremely low and high CRP concentrations in the limited timeframe typical for point-of-care testing. Methods: A noncompetitive, kinetic CRP immunoassay was developed that uses individual, porous microparticles as the solid phase. The microparticles were covalently coated with a monoclonal capture antibody, and the monoclonal detection antibody was labeled with europium. The one-step binding reaction was stopped by washing after 2 min of incubation, and the fluorescence signal of individual particles was measured. Results: The analytical detection limit (mean of zero calibrator + 3 SD) was 0.00016 mg/L CRP. Clinical samples were diluted 400-fold before assay to cover the CRP concentration range of 0.064–1200 mg/L. The assay correlated well with the Dade Behring N High Sensitivity CRP assay (for 0–10 mg/L, r = 0.969, Sy|x = 0.68, n = 54; for 0–350 mg/L, r = 0.969, Sy|x = 11.7, n = 100). The within- and between-run CVs based on calculated concentrations were, respectively, 9–16% and 14% at 0.11 mg/L, 4.5–12% and 8.2% at 4.2 mg/L, and 3.5–6.3% and 4.4% at 105 mg/L, with a CV &lt;15% at 0.2 mg/L and above. Conclusions: Use of the kinetic microparticle approach combined with time-resolved fluorometry allows ultrasensitive quantification of CRP in whole blood in 2 min with a linear assay range spanning more than four orders of magnitude.

Evaluation of the Xpert HCV Viral Load point-of-care assay from venepuncture-collected and finger-stick capillary whole-blood samples: a cohort study

2017 ◽  
Vol 2 (7) ◽  
pp. 514-520 ◽  
Author(s):  
Jason Grebely ◽  
Francois M J Lamoury ◽  
Behzad Hajarizadeh ◽  
Yasmin Mowat ◽  
Alison D Marshall ◽  
...  
Keyword(s):  
Cohort Study ◽  
Viral Load ◽  
Whole Blood ◽  
Point Of Care ◽  
Blood Samples ◽  
Load Point ◽  
Whole Blood Samples ◽  
Finger Stick ◽  
Point Of Care Assay

Point-of-care testing of the international normalized ratio in patients with antiphospholipid antibodies

2005 ◽  
Vol 94 (12) ◽  
pp. 1196-1202 ◽  
Author(s):  
Gregory P. Samsa ◽  
Thomas L. Ortel ◽  
Stephanie L. Perry
Keyword(s):  
Atrial Fibrillation ◽  
Whole Blood ◽  
Antiphospholipid Antibodies ◽  
Point Of Care ◽  
International Normalized Ratio ◽  
Absolute Difference ◽  
Factor X ◽  
Point Of Care Testing ◽  
Laboratory Plasma ◽  
Finger Stick

SummaryAntiphospholipid antibodies can influence the results of clotting tests in a subset of patients, which can be a major obstacle in monitoring warfarin. The aim was to determine if point-of-care testing of the International Normalized Ratio (INR) is influenced by antiphospholipid antibodies. We compared 59 patients receiving warfarin for a diagnosis of antiphosphoipid antibody syndrome (APS) to 49 patients receiving warfarin for atrial fibrillation to evaluate the consistency between INR results obtained by different methods. INR results obtained by finger stick (capillary whole-blood) and venipuncture (non-citrated and citrated whole-blood) were compared with our laboratory plasma-based prothrombin time assay. Five patients (8%) with APS and both elevated anti-β2glycoprotein I levels and positive lupus anticoagulants had non-measurable ProTime® INR results and generally higher Hemochron® Signature INR results than the plasma-based method, but the corresponding chromogenic factor X results were not supratherapeutic. For the remaining patients, differences between the plasma-based INR and the point-of-care INR results ranged from 0.2±0.2 to 0.4±0.3. The differences were similar for patients with APS and atrial fibrillation for all INR comparisons with the exception of the plasma-based method compared with the ProTime, which showed a mean absolute difference of 0.4±0.3 for APS patients and of 0.2±0.2 for atrial fibrillation patients (p=0.02). In a subset ofAPS patients, the ProTime® system will not yield an INR result and the HEMochron Signature (citrate and non-citrate whole-blood) INR results will exhibit elevated INR results. For this subset of APS patients, we suggest using an alternative method to monitor warfarin.

scholarly journals A novel whole blood coagulometer for NOAC testing

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Bakhru ◽  
X Jiang ◽  
L Chen ◽  
Y Wang ◽  
D Osmani ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Oral Anticoagulants ◽  
High Sensitivity ◽  
Funding Source ◽  
Reversal Agent ◽  
Private Company ◽  
Blood Samples ◽  
Undergo Emergency Surgery ◽  
Whole Blood Samples

Abstract Background While use of the non-vitamin K antagonist oral anticoagulants (NOACs) does not currently require routine coagulation monitoring, this can be highly desirable in at-risk patients, including those suffering major trauma or having to undergo emergency surgery, especially when a NOAC reversal agent is used. However, a point-of-care (PoC) device for the rapid measurement of clotting times in patients on NOACs is currently not available. Purpose To characterize the sensitivity of a novel PoC coagulometer to NOAC-induced anticoagulation, as well as quantify instrument precision, via venous whole blood samples freshly spiked with rivaroxaban, apixaban and edoxaban. Methods This study was conducted using healthy volunteers with normal coagulation lab values, including PT/INR and aPTT, confirmed via laboratory testing. Whole blood samples from two volunteers per NOAC were spiked with either 0 (sham), 75, 150, or 300 ng/mL of rivaroxaban, apixaban or edoxaban, in randomized order, each day for five days of testing. Each day, each spiked sample was run on five PoC coagulometers simultaneously for replicate measurement. Results PoC coagulometer clotting times exhibited a high degree of linearity spanning the measuring range, with R2 values approaching 1, and high sensitivity across NOAC concentrations tested (i.e. each concentration was statistically significantly different from the others), as well as a high level of precision across the five days of testing. Furthermore, the PoC coagulometer yielded notably low %CVs at each concentration tested, for each subject and anticoagulant, ranging from approximately 3–7% (Fig. 1, rivaroxaban and apixaban data from individual subjects shown). Conclusions These results suggest that this PoC coagulometer could be a valuable tool to assess the pharmacodynamic effects of the NOACs in emergency and other settings. The PoC coagulometer yields results within minutes at a patient's bedside, requiring only a drop of whole blood. Figure 1 Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Perosphere Technologies Inc.

scholarly journals Diagnostic Accuracy of SARS-CoV-2 Antigen Detection Test in Children: A Real-Life Study

2021 ◽  
Vol 9 ◽  
Author(s):  
Camille Jung ◽  
Corinne Levy ◽  
Emmanuelle Varon ◽  
Sandra Biscardi ◽  
Christophe Batard ◽  
...  
Keyword(s):  
Real Life ◽  
University Hospital ◽  
Rt Pcr ◽  
Life Study ◽  
Mean Delay ◽  
Positive Person ◽  
The Mean ◽  
Real Life Study ◽  
The University ◽  
Positive Groups

Naso-pharyngeal RT-PCR is the gold standard for the diagnosis of COVID-19, but there is a need for rapid and reliable tests. Some validation studies have used frozen aliquots mainly from adults. The aim of this real-life study was to test the performance of a SARS-CoV-2 rapid antigen test (SC2-RAT) in children. Symptomatic patients aged 0 to 17 years were recruited in the emergency department of the University Hospital of Creteil and in primary care pediatric practices from October 10, 2020 for 7 weeks. Each enrolled child had a SARS-CoV-2 RT-PCR test and a SC2-RAT from two distinct nasopharyngeal swabs. Among the 308 patients (mean [SD] age 4.9 [5.3] years), fever was the main symptom (73.4%), with no difference between COVID-19–negative and –positive groups. The prevalence of COVID-19 was 10.7% (95% CI 7.5–14.7). On the whole cohort, the sensitivity and specificity of the SC2-RAT compared to RT-PCR was 87.9% (95% CI 71.8–96.6) and 98.5% (95% CI 96.3–99.6). Considering samples with cycle threshold &gt;25, the sensibility was lower: 63.6% (95% CI 30.8–89.1) and the specificity 99.6% (95% CI 98.0–100.0). The mean delay to obtain an SC2-RAT result was &lt;15 min but was 3.2 h (SD 5.5) for an RT-PCR result. Contact with a COVID-19–positive person was more frequent for COVID-19–positive than –negative patients (n = 21, 61.6%, vs. n = 64, 24.6%; p &lt; 0.01). In real life, SC2-RAT seems reliable for symptomatic children, allowing to detect contagious children.

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