scholarly journals Logistic advantage of two-step screening strategy for SARS-CoV-2 at airport quarantine

2021 ◽  
Author(s):  
Isao Yokota ◽  
Peter Y Shane ◽  
Takanori Teshima
Keyword(s):  
Point Of Care ◽  
High Accuracy ◽  
Screening Strategy ◽  
Nucleic Acid Amplification ◽  
Point Of Care Testing ◽  
Chain Reaction ◽  
False Negatives ◽  
Imported Cases ◽  
Polymerase Chain ◽  
Antigen Testing

SummaryBackgroundAirport quarantine is required to reduce the risk of entry of travelers infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, it is challenging for both high accuracy and rapid turn-around time to coexist in testing; polymerase chain reaction (PCR) is time-consuming with high accuracy, while antigen testing is rapid with less accuracy.Methods88,924 (93.2%) of 95,457 arrivals at three international airports in Japan were tested for SARS-CoV-2 using self-collected saliva by a screening strategy with initial chemiluminescent enzyme immunoassay (CLEIA) followed by confirmatory nucleic acid amplification tests (NAAT) only for intermediate range antigen concentrations.Results254 (0.27%) persons were found to be SARS-CoV-2 antigen positive (≥ 4.0 pg/mL) by CLEIA. NAAT was required for confirmatory testing in 513 (0.54%) persons with intermediate antigen concentrations (0.67-4.0 pg/mL) whereby the virus was detected in 34 (6.6%) persons. This two-step strategy dramatically reduced the utilization of NAAT to approximately one out of every 200 test subjects.Estimated performance of this strategy did not show significant increase in false negatives as compared to performing NAAT in all subjects. Further reduction in imported cases may be achieved by post-screening quarantine.ConclusionsPoint of care testing by quantitative CLEIA using self-collected saliva is less labor-intensive and yields results rapidly, thus suitable as an initial screening test. Reserving NAAT for CLEIA indeterminate cases may prevent compromising accuracy while significantly improving the logistics of administering mass-screening at large venues.

scholarly journals Is Point-of-Care testing feasible and safe in care homes in England? An exploratory usability and accuracy evaluation of Point-of-Care Polymerase Chain Reaction test for SARS-COV-2

2020 ◽  
Author(s):  
Massimo Micocci ◽  
Adam L Gordon ◽  
Mikyung Kelly Seo ◽  
A. Joy Allen ◽  
Kerrie Davies ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Point Of Care ◽  
Care Home ◽  
Care Homes ◽  
Polymerase Chain Reaction Test ◽  
List Type ◽  
Point Of Care Testing ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Positive Agreement

AbstractIntroductionReliable rapid testing on COVID-19 is needed in care homes to reduce the risk of outbreaks and enable timely care. Point-of-care testing (POCT) in care homes could provide rapid actionable results. This study aimed to examine the usability and test performance of point of care polymerase chain reaction (PCR) for COVID-19 in care homes.MethodsPoint-of-care PCR for detection of SARS-COV2 was evaluated in a purposeful sample of four UK care homes. Test agreement with laboratory real-time PCR and usability and use errors were assessed.ResultsPoint of care and laboratory polymerase chain reaction (PCR) tests were performed on 278 participants. The point of care and laboratory tests returned uncertain results or errors for 17 and 5 specimens respectively. Agreement analysis was conducted on 256 specimens. 175 were from staff: 162 asymptomatic; 13 symptomatic. 69 were from residents: 59 asymptomatic; 10 symptomatic. Asymptomatic specimens showed 83.3% (95% CI: 35.9%-99.6%) positive agreement and 98.7% negative agreement (95% CI: 96.2%-99.7%), with overall prevalence and bias-adjusted kappa (PABAK) of 0.965 (95% CI: 0.932 – 0.999). Symptomatic specimens showed 100% (95% CI: 2.5%-100%) positive agreement and 100% negative agreement (95% CI: 85.8%-100%), with overall PABAK of 1. No usability-related hazards emerged from this exploratory study.ConclusionApplications of point-of-care PCR testing in care homes can be considered with appropriate preparatory steps and safeguards. Agreement between POCT and laboratory PCR was good. Further diagnostic accuracy evaluations and in-service evaluation studies should be conducted, if the test is to be implemented more widely, to build greater certainty on this initial exploratory analysis.Key pointsPoint of care tests (POCT) in care homes are feasible and could increase testing capacity for the control of COVID-19 infection.The test of agreement between POCT and laboratory PCR for care home residents and the staff was good.Adoption of POCT in care homes can be considered with appropriate preparatory steps and safeguards in place.Repetitive errors and test malfunctioning can be mitigated with bespoke training for care home staff.Integrated care pathways should be investigated to test the high variability of the context of use.

scholarly journals Recent Advances of Fluid Manipulation Technologies in Microfluidic Paper-Based Analytical Devices (μPADs) toward Multi-Step Assays

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 269 ◽  
Author(s):  
Taehoon H. Kim ◽  
Young Ki Hahn ◽  
Minseok S. Kim
Keyword(s):  
Developing Countries ◽  
Point Of Care ◽  
Enzyme Linked Immunosorbent Assay ◽  
Point Of Care Testing ◽  
Chain Reaction ◽  
Medical Benefits ◽  
Diagnostic Cost ◽  
Polymerase Chain ◽  
Improved Performance ◽  
Fluid Manipulation

Microfluidic paper-based analytical devices (μPADs) have been suggested as alternatives for developing countries with suboptimal medical conditions because of their low diagnostic cost, high portability, and disposable characteristics. Recently, paper-based diagnostic devices enabling multi-step assays have been drawing attention, as they allow complicated tests, such as enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR), which were previously only conducted in the laboratory, to be performed on-site. In addition, user convenience and price of paper-based diagnostic devices are other competitive points over other point-of-care testing (POCT) devices, which are more critical in developing countries. Fluid manipulation technologies in paper play a key role in realizing multi-step assays via μPADs, and the expansion of biochemical applications will provide developing countries with more medical benefits. Therefore, we herein aimed to investigate recent fluid manipulation technologies utilized in paper-based devices and to introduce various approaches adopting several principles to control fluids on papers. Fluid manipulation technologies are classified into passive and active methods. While passive valves are structurally simple and easy to fabricate, they are difficult to control in terms of flow at a specific spatiotemporal condition. On the contrary, active valves are more complicated and mostly require external systems, but they provide much freedom of fluid manipulation and programmable operation. Both technologies have been revolutionized in the way to compensate for their limitations, and their advances will lead to improved performance of μPADs, increasing the level of healthcare around the world.

scholarly journals Real-World Clinical Performance of the Abbott Panbio with Nasopharyngeal, Throat and Saliva Swabs Among Symptomatic Individuals with COVID-19

2021 ◽  
Author(s):  
William Stokes ◽  
Byron M. Berenger ◽  
Danielle Portnoy ◽  
Brittney Scott ◽  
Jonas Szelewicki ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Clinical Performance ◽  
Point Of Care ◽  
Community Setting ◽  
Rt Pcr ◽  
Chain Reaction ◽  
False Negatives ◽  
Polymerase Chain ◽  
Antigen Tests ◽  
Health Canada

Abstract BACKGROUND Point of Care SARS-CoV-2 antigen tests, such as the Abbott Panbio, have great potential to help combat the COVID-19 pandemic. The Panbio is Health Canada approved for the detection of SARS-CoV-2 in symptomatic individuals within the first 7 days of COVID-19 symptom onset(s). METHODS Symptomatic adults recently diagnosed with COVID-19 in the community were recruited into the study. Paired nasopharyngeal (NP), throat, and saliva swabs were collected, with one paired swab tested immediately with the Panbio, and the other transported in universal transport media and tested using reverse-transcriptase polymerase chain reaction (RT-PCR). We also prospectively evaluated results from assessment centres. For those individuals, an NP swab was collected for Panbio testing and paired with RT-PCR results from parallel NP or throat swabs. RESULTS 145 individuals were included in the study. Collection of throat and saliva was stopped early due to poorer performance (throat sensitivity 57.7%, n = 61, and saliva sensitivity 2.6%, n = 41). NP swab sensitivity was 87.7% [n = 145, 95% confidence interval (CI) 81.0% − 92.7%]. There were 1,641 symptomatic individuals tested by Panbio in assessment centres, with 268/1641 (16.3%) positive for SARS-CoV-2. There were 37 false negatives and 2 false positives, corresponding to a sensitivity and specificity of 86.1% [95% CI 81.3% − 90.0%] and 99.9% [95% CI 99.5% − 100.0%], respectively. CONCLUSIONS The Panbio test reliably detects most cases of SARS-CoV-2 from adults in the community setting presenting within 7 days of symptom onset using nasopharyngeal swabs. Throat and saliva swabs are not reliable specimens for the Panbio.

scholarly journals Screening, Diagnostic and Prognostic Tests for COVID-19: A Comprehensive Review

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 561
Author(s):  
Mariana Ulinici ◽  
Serghei Covantev ◽  
James Wingfield-Digby ◽  
Apostolos Beloukas ◽  
Alexander G. Mathioudakis ◽  
...  
Keyword(s):  
Point Of Care ◽  
Standard Test ◽  
Current Evidence ◽  
Molecular Testing ◽  
Rt Pcr ◽  
Diagnostic Screening ◽  
Comprehensive Review ◽  
Prognostic Tests ◽  
Polymerase Chain ◽  
Antigen Testing

While molecular testing with real-time polymerase chain reaction (RT-PCR) remains the gold-standard test for COVID-19 diagnosis and screening, more rapid or affordable molecular and antigen testing options have been developed. More affordable, point-of-care antigen testing, despite being less sensitive compared to molecular assays, might be preferable for wider screening initiatives. Simple laboratory, imaging and clinical parameters could facilitate prognostication and triage. This comprehensive review summarises current evidence on the diagnostic, screening and prognostic tests for COVID-19.

West Nile Virus Chorioretinitis in the Presence of Negative Cerebrospinal Fluid Polymerase Chain Reaction Results

2021 ◽  
pp. 247412642097925
Author(s):  
Kareem Moussa ◽  
Karen W. Jeng-Miller ◽  
Leo A. Kim ◽  
Dean Eliott
Keyword(s):  
Cerebrospinal Fluid ◽  
West Nile Virus ◽  
Cross Sectional Study ◽  
Nucleic Acid Amplification ◽  
Sectional Study ◽  
Chain Reaction ◽  
West Nile ◽  
Cross Sectional ◽  
Positive Serum ◽  
Polymerase Chain

Purpose: This work aims to evaluate the utility of nucleic acid amplification testing (NAAT) and serology in confirming West Nile Virus (WNV) infection in patients with suspected WNV chorioretinitis. Methods: A retrospective cross-sectional study was conducted of a cluster of patients who presented to the Retina Service of Massachusetts Eye and Ear between September and October 2018. Results: Three patients were identified with classic WNV chorioretinitis lesions with negative cerebrospinal fluid NAAT and positive serum serology findings. The diagnosis of WNV chorioretinitis was made based on the appearance of the fundus lesions and the presence of characteristic findings on fluorescein angiography as previously described in the literature. Conclusions: This report highlights 3 unique cases of WNV chorioretinitis in which NAAT of cerebrospinal fluid failed to identify WNV as the inciting agent. These cases stress the importance of serum serologic testing in diagnosing WNV infection.

scholarly journals A Self-Contained Portable Polymerase-Chain-Reaction System Integrated with Electromagnetic Mini-Actuators for Bi-Directional Fluid Transport

2011 ◽  
Vol 27 (3) ◽  
pp. 357-364
Author(s):  
B. T. Chia ◽  
S.-A. Yang ◽  
M.-Y. Cheng ◽  
C.-W. Lin ◽  
Y.-J. Yang
Keyword(s):  
Polymerase Chain Reaction ◽  
Fluid Transport ◽  
Point Of Care ◽  
Reaction System ◽  
Thermal Characteristics ◽  
Pcr Amplification ◽  
Chain Reaction ◽  
Rapid Temperature ◽  
Small Footprint ◽  
Polymerase Chain

ABSTRACTIn this paper, the development of a portable polymerase chain reaction (PCR) device is presented. Integrating electromagnetic mini-actuators for bi-directional fluid transport, the proposed device, whose dimension is 67mm × 66mm × 25mm, can be fully operated with a 5V DC voltage. The device consists of four major parts: A disposable channel chip in which PCR mixture is manipulated and reacted, a heater chip which generates different temperature zones for PCR reaction, a linear actuator array for pumping PCR mixture, and a circuit module for controlling and driving the system. The advantages of the device include the rapid temperature responses associated with continuous-flow-type PCR devices, as well as the programmable thermal cycling associated with chamber-type PCR devices. The thermal characteristics are measured and discussed. PCR amplification is successfully performed for the 122 bp segment of MCF-7/adr cell line. Due to its small footprint, this self-contained system potentially can be employed for point-of-care (POC) applications.

scholarly journals RAPID AND SPESIFIC DETECTION OF MYCOBACTERIUM TUBERCULOSIS USING POLYMERASE CHAIN REACTION

2019 ◽  
Vol 3 (2) ◽  
pp. 83
Author(s):  
Anita Kurniati ◽  
Desak Nyoman Surya Suameitra Dewi ◽  
Ni Nyoman Purwani
Keyword(s):  
Polymerase Chain Reaction ◽  
Mycobacterium Tuberculosis ◽  
Clinical Specimen ◽  
Laboratory Diagnosis ◽  
Nucleic Acid Amplification ◽  
Valuable Insight ◽  
Chain Reaction ◽  
Severe Condition ◽  
Middle Income ◽  
Polymerase Chain

Background: Tuberculosis (TB) is one of the major causes of health burden worldwide, especially in lower middle-income countries. TB is caused by Mycobacterium tuberculosis (MTB) and characterized by severe condition incuding coughing and fever. Purpose: To review the current methods for detection of TB using Polymerase Chain Reaction (PCR). Review: several studies have been done to give valuable insight into TB transmission, diagnosis, and treatment, however research  is constantly  needed  to decrease the incidence of eradicate TB. This infectious disease still give big health problem in all over the world by being second in causing high mortality rates after HIV/AIDS.  A specific, sensitive, rapid and cheap method for TB and other mycobacteria diagnosis in clinical specimen is a desperate needed in the laboratory diagnosis and hence management of tuberculosis. PCR as one of nucleic acid amplification assays have revolutionized MTB detection. Since it was first invented in fifteen years ago, it’s been through many developments. Conclusion: PCR  is one of the most specific and sensitive method currently available for TB diagnosis that can also detect in in all types of specimens obtained from TB patients.

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