scholarly journals 678. Rapid Molecular SARS-CoV-2 Detection by Abbott ID NOW Is Reliable in Pediatric Patients

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S441-S441
Author(s):  
Catherine Murphy ◽  
Emily Sheboy Scarcello ◽  
Sheila M Nolan
Keyword(s):  
Pediatric Patients ◽  
Point Of Care ◽  
False Negative ◽  
Pediatric Primary Care ◽  
Test Results ◽  
Point Of Care Testing ◽  
Conventional Pcr ◽  
Negative Results ◽  
Percent Positivity ◽  
Pcr Test

Abstract Background The COVID-19 Pandemic demonstrated the importance of rapid, accurate, point of care testing to control spread of the virus. The availability of this testing has been crucial to re-opening schools, keeping children safely in schools, and returning children to school quickly following illness. The Abbott ID Now molecular assay to detect SARS-CoV-2 was granted Emergency Use Authorization in March 2020. Reports of lower sensitivity compared with conventional PCR prompted some school districts to require confirmatory conventional PCR for negative rapid molecular results to return children to school. In this study we aim to determine the sensitivity and specificity of the Abbott ID NOW molecular SARS-CoV-2 test in a large pediatric primary care practice. Methods A retrospective observational study was performed using data from 25 pediatric primary care sites in the Boston Children’s Health Physicians network, a large multispecialty pediatric practice in New York and Connecticut. Data were extracted from the electronic health record for all patients 0-22 years of age who had an Abbott ID NOW rapid molecular COVID-19 assay from October 1, 2020 - February 28, 2021. For all patients with rapid tests, we identified patients who had a conventional PCR test sent within 1 day before or 1 day after the ID NOW test. The result of the conventional PCR test was considered the “true” result. All discrepant test results were identified. Results During the study period, 14993 patients had ID NOW testing performed. The percent positivity was 8.5%. The percent positivity in our practices paralleled that in the surrounding community throughout the winter surge of COVID-19. 500 patients had confirmatory testing sent within 1 day before or after the ID NOW test (15 positive and 485 negative results). Based on the conventional PCR test results, 2 of 15 positive results were false positive and only 1 of 485 negative results was a false negative, resulting in a sensitivity of 93% and specificity of 99.6%. The false negative result was in a patient with nasal congestion whose mother was COVID positive. Conclusion Rapid, molecular, point of care testing is an important tool to identify SARS-CoV-2 in pediatric patients and limit school absences. The ID NOW assay is highly sensitive and specific in a real-world pediatric setting. Disclosures All Authors: No reported disclosures

scholarly journals Diagnostic testing for feline panleukopenia in a shelter setting: a prospective, observational study

2021 ◽  
pp. 1098612X2110053
Author(s):  
Linda S Jacobson ◽  
Kyrsten J Janke ◽  
Jolene Giacinti ◽  
J Scott Weese
Keyword(s):  
Point Of Care ◽  
Diagnostic Testing ◽  
False Negative ◽  
Clinical Signs ◽  
Test Results ◽  
Feline Panleukopenia Virus ◽  
Negative Results ◽  
Copy Numbers ◽  
Rectal Swabs ◽  
Vaccination History

Objectives The aim of this study was to optimize the diagnosis of feline panleukopenia virus (FPV) in a shelter setting by: (1) comparing the results of the canine parvovirus IDEXX SNAP Parvo (SNAP) point-of-care ELISA with a commercial FPV quantitative real-time PCR (qPCR) test; (2) assessing whether vomit and anal/rectal swabs could be used for early diagnosis; and (3) clarifying the interpretation of weak-positive SNAP test results. Methods The study included shelter cats and kittens with incomplete or unknown vaccination history that had clinical signs suspicious for feline panleukopenia and fecal SNAP and PCR tests performed within 24 h of onset. Feces, anal/rectal swabs and vomit were tested using SNAP and PCR, with fecal PCR utilized as the reference standard. Results One hundred and forty-five cats were included. Seventeen were diagnosed with FPV infection and 62 were negative; 66 could not be individually designated because they were co-housed. Sensitivity was as follows: fecal SNAP 55% (n = 102; 95% confidence interval [CI] 32–77); swab SNAP 30% (n = 55; 95% CI 7–65); swab PCR 77% (n = 55; 95% CI 46–95); and vomit PCR 100% (n = 17; 95% CI 16–100). Specificity was high (96–100%) for all sample and test types. For PCR-positive fecal samples, true-positive SNAP tests (including weak positives) had significantly higher DNA viral copy numbers than false-negative SNAP tests ( P = 0.0031). Conclusions and relevance The SNAP ELISA should be viewed as an initial diagnostic test to rule in feline panleukopenia. Positive fecal SNAP test results, including weak positives, are highly likely to be true positives in clinically affected animals. Negative results in clinically affected animals are unreliable and should be followed up with PCR testing.

scholarly journals Superiority of MALDI-TOF Mass Spectrometry over Real-Time PCR for SARS-CoV-2 RNA Detection

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 730
Author(s):  
Magda Rybicka ◽  
Ewa Miłosz ◽  
Krzysztof Piotr Bielawski
Keyword(s):  
Mass Spectrometry ◽  
Gold Standard ◽  
Viral Genome ◽  
False Negative ◽  
Rt Pcr ◽  
Rna Detection ◽  
Maldi Tof ◽  
Negative Results ◽  
False Negative Results ◽  
Pcr Test

At present, the RT-PCR test remains the gold standard for early diagnosis of SARS-CoV-2. Nevertheless, there is growing evidence demonstrating that this technique may generate false-negative results. Here, we aimed to compare the new mass spectrometry-based assay MassARRAY® SARS-CoV-2 Panel with the RT-PCR diagnostic test approved for clinical use. The study group consisted of 168 suspected patients with symptoms of a respiratory infection. After simultaneous analysis by RT-PCR and mass spectrometry methods, we obtained discordant results for 17 samples (10.12%). Within fifteen samples officially reported as presumptive positive, 13 were positive according to the MS-based assay. Moreover, four samples reported by the officially approved RT-PCR as negative were positive in at least one MS assay. We have successfully demonstrated superior sensitivity of the MS-based assay in SARS-CoV-2 detection, showing that MALDI-TOF MS seems to be ideal for the detection as well as discrimination of mutations within the viral genome.

Requiem for the STAT Test: Automation and Point of Care Testing

2019 ◽  
Author(s):  
Gurmukh Singh ◽  
Natasha M Savage ◽  
Brandy Gunsolus ◽  
Kellie A Foss
Keyword(s):  
Point Of Care ◽  
Turnaround Time ◽  
Test Automation ◽  
Test Results ◽  
Point Of Care Testing ◽  
Tube System ◽  
Front End ◽  
Laboratory Test Results ◽  
Batch Testing ◽  
Pneumatic Tube System

Abstract Objective Quick turnaround of laboratory test results is needed for medical and administrative reasons. Historically, laboratory tests have been requested as routine or STAT. With a few exceptions, a total turnaround time of 90 minutes has been the usually acceptable turnaround time for STAT tests. Methods We implemented front-end automation and autoverification and eliminated batch testing for routine tests. We instituted on-site intraoperative testing for selected analytes and employed point of care (POC) testing judiciously. The pneumatic tube system for specimen transport was expanded. Results The in-laboratory turnaround time was reduced to 45 minutes for more than 90% of tests that could reasonably be ordered STAT. With rare exceptions, the laboratory no longer differentiates between routine and STAT testing. Having a single queue for all tests has improved the efficiency of the laboratory. Conclusion It has been recognized in manufacturing that batch processing and having multiple queues for products are inefficient. The same principles were applied to laboratory testing, which resulted in improvement in operational efficiency and elimination of STAT tests. We propose that the target for in-laboratory turnaround time for STAT tests, if not all tests, be 45 minutes or less for more than 90% of specimens.

scholarly journals Serologic and Molecular Diagnosis of Anaplasma platys and Ehrlichia canis Infection in Dogs in an Endemic Region

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 488
Author(s):  
Bianca Lara ◽  
Anne Conan ◽  
Mary Anna Thrall ◽  
Jennifer K. Ketzis ◽  
Gillian Carmichael Branford ◽  
...  
Keyword(s):  
Early Stage ◽  
Point Of Care ◽  
False Negative ◽  
Ehrlichia Canis ◽  
Test Results ◽  
Anaplasma Platys ◽  
Endemic Region ◽  
Life Threatening ◽  
Improve Patient Management ◽  
Antibody Levels

Anaplasma platys and Ehrlichia canis are obligate intracellular, tick-borne rickettsial pathogens of dogs that may cause life-threatening diseases. In this study, we assessed the usefulness of PCR and a widely used commercial antibody-based point-of-care (POC) test to diagnose A. platys and E. canis infection and updated the prevalence of these pathogens in dogs inhabiting the Caribbean island of Saint Kitts. We detected A. platys in 62/227 (27%), E. canis in 84/227 (37%), and the presence of both in 43/227 (19%) of the dogs using PCR. POC testing was positive for A. platys in 53/187 (28%), E. canis in 112/187 (60%), and for both in 42/187 (22%) of the samples tested. There was only a slight agreement between A. platys PCR and POC test results and a fair agreement for E. canis PCR and POC test results. Our study suggests that PCR testing may be particularly useful in the early stage of infection when antibody levels are low or undetectable, whereas, POC test is useful when false-negative PCR results occur due to low bacteremia. A combination of PCR and POC tests may increase the ability to diagnose A. platys and E. canis infection and consequently will improve patient management.

Point-of-care testing, medical error, and patient safety: a 2007 assessment

2007 ◽  
Vol 45 (6) ◽  
Author(s):  
Sharon S. Ehrmeyer ◽  
Ronald H. Laessig
Keyword(s):  
Patient Safety ◽  
Full Advantage ◽  
Medical Error ◽  
Point Of Care ◽  
Data Interpretation ◽  
Medical Data ◽  
Test Results ◽  
Point Of Care Testing ◽  
Proper Design

AbstractPoint-of-care testing (POCT) is the fastest growing segment of a US$30 billion worldwide market. “Errors” in the testing process, as well as medical data interpretation and treatment associated with POCT, are recognized as leading to major compromises of patient safety. In today's environment, most testing errors (pre-analytical, analytical and post-analytical) can be virtually eliminated by proper design of testing systems. We cite examples of two systems that have made exceptional progress in this respect. It has been recently suggested that the basic errors associated with the testing process are amplified in the POC setting. Two of the amplifiers – incoherent regulations and failure of clinician/caregivers to respond appropriately to POCT results – lead us to recognize additional changes in today's POCT environment. The first is a willingness of manufacturers, not laboratories, to take responsibility for the quality of test results – an outgrowth of an industrial philosophy called autonomation. The second is a need to substantially modify the clinician/caregiver test utilization paradigm to take full advantage of POCT results, available on site in real time. Both have already begun to take place.Clin Chem Lab Med 2007;45:766–73.

scholarly journals False-Negative Results in Point-of-Care Qualitative Human Chorionic Gonadotropin (hCG) Devices Due to Excess hCGβ Core Fragment

2009 ◽  
Vol 55 (7) ◽  
pp. 1389-1394 ◽  
Author(s):  
Ann M Gronowski ◽  
Mark Cervinski ◽  
Ulf-Håkan Stenman ◽  
Alison Woodworth ◽  
Lori Ashby ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Point Of Care ◽  
False Negative ◽  
The Core ◽  
Core Fragment ◽  
Negative Results ◽  
False Negative Results ◽  
Positive Results ◽  
Urine Specimens

Abstract Background: During pregnancy, human chorionic gonadotropin (hCG) immunoreactivity in urine consists of intact hCG as well as a number of hCG variants including the core fragment of hCGβ (hCGβcf). We identified 3 urine specimens with apparent false-negative results using the OSOM® hCG Combo Test (Genzyme Diagnostics) qualitative hCG device and sought to determine whether an excess of 1 of the fragments or variants might be the cause of the interference. Methods: We measured concentrations of hCG variants in the urine from 3 patients with apparent false-negative hCG results. Purified hCG variants were added to urines positive for hCG and tested using the OSOM, ICON® 25 hCG (Beckman Coulter), and hCG Combo SP® Brand (Cardinal Health) devices. Results: Dilution of these 3 urine samples resulted in positive results on the OSOM device. Quantification of hCG variants in each of the 3 patient urine specimens demonstrated that hCGβcf occurred in molar excess of intact hCG. Addition of purified hCGβcf to hCG-positive urines caused false-negative hCG results using the OSOM and ICON qualitative urine hCG devices. Conclusions: Increased concentrations of hCGβcf can cause false-negative results on the OSOM and ICON qualitative urine hCG devices. .

scholarly journals Reducing False Negative PCR Test for COVID-19

2020 ◽  
Vol 9 (3) ◽  
pp. 408-410
Author(s):  
Fatemeh Bahreini ◽  
Rezvan Najafi ◽  
Razieh Amini ◽  
Salman Khazaei ◽  
Saeid Bashirian
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
False Negative ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Creative Commons ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Pcr Test

As the SARS-CoV-2 (COVID-19) pandemic spreads rapidly, there is need for a diagnostic test with high accuracy to detect infected individuals especially those without symptoms. Real-time polymerase chain reaction (RT-PCR) is a common molecular test for diagnosing SARS-CoV-2. If some factors are not taken into consideration when performing this test, it can have a relatively large number of false negative results. In this article, we discuss important considerations that could lead to false negative test reduction. Key words: • SARS-CoV-2 • COVID-19 • Real time polymerase chain reaction • RT-PCR test • Diagnosis • False negatives • Genetics • Emerging disease   Copyright © 2020 Bahreini et al. Published by Global Health and Education Projects, Inc. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0)which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in this journal, is properly cited.

scholarly journals Performance of SARS-CoV-2 Serology tests: Are they good enough?

2020 ◽  
Author(s):  
Isabelle Piec ◽  
Emma English ◽  
M Annette Thomas ◽  
Samir Dervisevic ◽  
William D Fraser ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Respiratory Infections ◽  
Point Of Care ◽  
False Negative ◽  
Rapid Test ◽  
Diagnostic Sensitivity ◽  
Medical Community ◽  
Antibody Detection ◽  
Serological Tests ◽  
Negative Results

AbstractBackgroundIn the emergency of the SARS-CoV-2 pandemic, great efforts were made to quickly provide serology testing to the medical community however, these methods have been introduced into clinical practice without the complete validation usually required by the regulatory organizations.MethodsSARS-CoV-2 patient samples (n=43) were analysed alongside pre-pandemic control specimen (n=50), confirmed respiratory infections (n=50), inflammatory polyarthritis (n=22) and positive for thyroid stimulating immunoglobulin (n=30). Imprecision, diagnostic sensitivity and specificity and concordance were evaluated on IgG serologic assays from EuroImmun, Epitope Diagnostics (EDI), Abbott Diagnostics and DiaSorin and a rapid IgG/IgM test from Healgen.ResultsEDI and EuroImmun imprecision was 0.02-14.0% CV. Abbott and DiaSorin imprecision (CV) ranged from 5.2% - 8.1% and 8.2% - 9.6% respectively. Diagnostic sensitivity of the assays were 100% (CI: 80-100%) for Abbott, EDI and EuroImmun and 95% (CI: 73-100%) for DiaSorin at ≥14 days post PCR. Only the Abbott assay had a diagnostic specificity of 100% (CI: 91-100%). EuroImmun cross-reacted in 3 non-SARS-CoV-2 respiratory infections and 2 controls. The DiaSorin displayed more false negative results and cross-reacted in six cases across all conditions tested. EDI had one cross-reactive sample. The Healgen rapid test showed excellent sensitivity and specificity. Overall, concordance of the assays ranged from 76.1% to 97.9%.ConclusionsSerological tests for SARS-CoV-2 showed good analytical performance. The head-to-head analysis of samples revealed differences in results that may be linked to the use of nucleocapsid or spike proteins. The point of care device tested demonstrated adequate performance for antibody detection.

scholarly journals False Covid-19 Test Results – Could We Do Things Better? A Personal Opinion

2020 ◽  
Vol 8 (5) ◽  
Author(s):  
Suzanne Lisbeth Ekelund
Keyword(s):  
False Positive ◽  
False Negative ◽  
Test Results ◽  
Negative Results ◽  
False Negative Results ◽  
Personal Opinion ◽  
Potential Problems

This paper describes the problems with false covid-19 test results, both false positive and false negative results. The problems are related to the quality of tests, test sampling and the currently limited follow-up procedures. A test and follow-up strategy that could decrease the potential problems is suggested.

scholarly journals Effect of urine adulterants on commercial drug abuse screening test strip results

2020 ◽  
Vol 71 (1) ◽  
pp. 87-93
Author(s):  
Ivana Rajšić ◽  
Dragana Javorac ◽  
Simona Tatović ◽  
Aleksandra Repić ◽  
Danijela Đukić-Ćosić ◽  
...  
Keyword(s):  
Drug Abuse ◽  
False Negative ◽  
Test Strip ◽  
Lemon Juice ◽  
Screening Tests ◽  
Urine Specimen ◽  
Test Results ◽  
Negative Results ◽  
Urine Drug ◽  
Validity Tests

AbstractImmunochromatographic strips for urine drug screening tests (UDSTs) are common and very suitable for drug abuse monitoring, but are also highly susceptible to adulterants kept in the household, which can significantly alter test results. The aim of this study was to see how some of these common adulterants affect UDST results in practice and whether they can be detected by sample validity tests with pH and URIT 11G test strips. To this end we added household chemicals (acids, alkalis, oxidizing agents, surfactants, and miscellaneous substances) to urine samples positive for amphetamine, 3,4-methylenedioxymethamphetamine (MDMA), tetrahydrocannabinol, heroin, cocaine, or benzodiazepines (diazepam or alprazolam) and tested them with one-component immunochromatographic UDST strips. The UDST for cocaine resisted adulteration the most, while the cannabis test produced the most false negative results. The most potent adulterant that barely changed the physiological properties of urine specimens and therefore escaped adulteration detection was vinegar. Besides lemon juice, it produced the most false negative test results. In conclusion, some urine adulterants, such as vinegar, could pass urine specimen validity test and remain undetected by laboratory testing. Our findings raise concern about this issue of preventing urine tampering and call for better control at sampling, privacy concerns notwithstanding, and better sample validity tests.

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