scholarly journals Performance of the BinaxNOW COVID-19 Antigen Rapid Diagnostic Test for the Detection of SARS-CoV-2

2021 ◽  
Author(s):  
Fernando A Ocampo Gonzalez ◽  
Nicholas M Moore
Keyword(s):  
Nucleic Acid ◽  
Diagnostic Tests ◽  
Healthcare Workers ◽  
Turnaround Time ◽  
Rapid Diagnostic Tests ◽  
Nucleic Acid Amplification ◽  
Substantial Agreement ◽  
Cycle Number ◽  
Percent Agreement ◽  
Κ Statistic

Abstract Background: Diagnosis of COVID-19 disease primarily relies on nucleic acid amplification tests (NAAT) that amplify and detect viral RNA in specimens. These methods are expensive and time consuming. Antigen-based rapid diagnostic tests can substantially decrease turnaround time.Methods: We analyzed paired anterior nares swabs collected from symptomatic patients and asymptomatic healthcare workers being tested COVID-19. One swab was used for a direct RDT and the results were compared to NAAT.Results: 89 paired specimens were evaluated. The positive percent agreement (PPA) for the antigen RDT was 68.2%, and the negative percent agreement (NPA) was 98.5%. Despite a low PPA, the Κ statistic was 0.733 indicating substantial agreement with the NAAT result. The median cycle number in paired specimens with concordant results was significantly lower than in discordant specimens (21.3 versus 32.3; P=0.003).Conclusions: The RDT showed modest PPA and high NPA when compared to NAAT. The quick TAT and use of an inexpensive test more frequently could be useful in settings in which results from NAAT testing is delayed.

scholarly journals 2356. Increased Clinical Specificity with Ultrasensitive Detection of Clostridioides difficile Toxins: Reduction of Overdiagnosis Compared with Nucleic Acid Amplification Tests

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S811-S812 ◽  
Author(s):  
Johanna Sandlund ◽  
Joel Estis ◽  
Phoebe Katzenbach ◽  
Niamh Nolan ◽  
Kirstie Hinson ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Disease Severity ◽  
Single Molecule ◽  
Clinical Performance ◽  
Neutralization Assay ◽  
Nucleic Acid Amplification ◽  
Clostridioides Difficile ◽  
Percent Agreement ◽  
Clostridioides Difficile Infection ◽  
Healthcare Associated

Abstract Background Clostridioides difficile infection (CDI) is one of the most common healthcare-associated infections, resulting in significant morbidity, mortality, and economic burden. Diagnosis of CDI relies on the assessment of clinical presentation and laboratory tests. We have evaluated the clinical performance of ultrasensitive Single Molecule Counting technology for detection of C. difficile toxins A and B. Methods Stool specimens from 298 patients with suspected CDI were tested with nucleic acid amplification test (NAAT; BD MAX™ Cdiff assay or Xpert® C. difficile assay) and Singulex Clarity® C. difficile toxins A/B assay. Specimens with discordant results were tested with cell cytotoxicity neutralization assay (CCNA), and results were correlated with disease severity and outcome. Results There were 64 NAAT-positive and 234 NAAT-negative samples. Of the 32 NAAT+/Clarity− and 4 NAAT-/Clarity+ samples, there were 26 CCNA− and 4 CCNA- samples, respectively. CDI relapse or overall death was more common in NAAT+/toxin+ patients than in NAAT+/toxin− and NAAT−/toxin− patients, and NAAT+/toxin+ patients were 3.7 times more likely to experience relapse or death (Figure 1). The clinical specificity of Clarity and NAAT was 97.4% and 89.0%, respectively, and overdiagnosis was over three times more common in NAAT+/toxin− than in NAAT+/toxin+ patients (Figure 2). Negative percent agreement between NAAT and Clarity was 98.3%, and positive percent agreement increased from 50.0% to effective 84.2% and 94.1% after CCNA testing and clinical assessment. Conclusion The Clarity assay was superior to NAATs in diagnosis of CDI, by reducing overdiagnosis and thereby increasing clinical specificity, and presence of toxins was associated with disease severity and outcome. Disclosures All authors: No reported disclosures.

scholarly journals Analytical and Clinical Comparison of Three Nucleic Acid Amplification Tests for SARS-CoV-2 Detection

2020 ◽  
Vol 58 (9) ◽  
Author(s):  
Elizabeth Smith ◽  
Wei Zhen ◽  
Ryhana Manji ◽  
Deborah Schron ◽  
Scott Duong ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Severe Acute Respiratory Syndrome ◽  
Drug Administration ◽  
Clinical Performance ◽  
Absolute Quantification ◽  
Nucleic Acid Amplification ◽  
Clinical Correlation ◽  
Molecular Assays ◽  
Percent Agreement ◽  
Rna Transcript

ABSTRACT Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in December 2019 and has quickly become a worldwide pandemic. In response, many diagnostic manufacturers have developed molecular assays for SARS-CoV-2 under the Food and Drug Administration (FDA) Emergency Use Authorization (EUA) pathway. This study compared three of these assays, the Hologic Panther Fusion SARS-CoV-2 assay (Fusion), the Hologic Aptima SARS-CoV-2 assay (Aptima), and the BioFire Defense COVID-19 test (BioFire), to determine analytical and clinical performance as well as workflow. All three assays showed similar limits of detection (LODs) using inactivated virus, with 100% detection, ranging from 500 to 1,000 genome equivalents/ml, whereas use of a quantified RNA transcript standard showed the same trend but had values ranging from 62.5 to 125 copies/ml, confirming variability in absolute quantification of reference standards. The clinical correlation found that the Fusion and BioFire assays had a positive percent agreement (PPA) of 98.7%, followed by the Aptima assay at 94.7%, compared to the consensus result. All three assays exhibited 100% negative percent agreement (NPA). Analysis of discordant results revealed that all four samples missed by the Aptima assay had cycle threshold (Ct) values of >37 by the Fusion assay. In conclusion, while all three assays showed similar relative LODs, we showed differences in absolute LODs depending on which standard was employed. In addition, the Fusion and BioFire assays showed better clinical performance, while the Aptima assay showed a modest decrease in overall PPA. These findings should be kept in mind when making platform testing decisions.

scholarly journals Performance evaluation of the BD SARS-CoV-2 reagents for the BD MAX™ system

2021 ◽  
Author(s):  
Karen Yanson ◽  
William Laviers ◽  
Lori Neely ◽  
Elizabeth Lockamy ◽  
Luis Carlos Castillo-Hernandez ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Clinical Study ◽  
Nucleic Acid ◽  
Clinical Performance ◽  
Nucleic Acid Amplification ◽  
Standard Approach ◽  
Limits Of Detection ◽  
Percent Agreement ◽  
Post Market ◽  
Roche Cobas

Background Nucleic acid amplification testing (NAAT) for SARS-CoV-2 is the standard approach for confirming COVID-19 cases. This study compared results between two Emergency Use Authorization (EUA) NAATs, with two additional EUA NAATs utilized for discrepant testing. Methods The limits of detection (LOD) for the BD SARS-CoV-2 Reagents for BD MAX™ System (“MAX SARS-CoV-2 assay”), the Biomerieux BioFire® Respiratory Panel 2.1 (“BioFire SARS-CoV-2 assay”), the Roche cobas SARS-CoV-2 assay (“cobas SARS-CoV-2 assay”), and the Hologic Aptima® SARS-CoV-2 assay Panther® (“Aptima SARS-CoV-2 assay”) NAAT systems were determined using a total of 84 contrived nasopharyngeal specimens with seven target levels for each comparator. The positive and negative percent agreement (PPA and NPA, respectively) of the MAX SARS-CoV-2 assay, compared to the Aptima SARS-CoV-2 assay, was evaluated in a post-market clinical study utilizing 708 nasopharyngeal specimens collected from suspected COVID-19 cases. Discordant testing was achieved using cobas and BioFire SARS-CoV-2 NAATs. Results In this study, the measured LOD for the MAX SARS-CoV-2 assay (251 copies/mL; [95%CI: 186, 427]) was comparable to the cobas SARS-CoV-2 assay (298 copies/mL; [95%CI: 225, 509]) and the BioFire SARS-CoV-2 assay (302 copies/mL; [95%CI: 219, 565]); the Aptima SARS-CoV-2 assay had a LOD of 612 copies/mL; [95%CI: 474, 918]. The MAX SARS-CoV-2 assay had a PPA of 100% (95%CI: [97.3%-100.0%]) and a NPA of 96.7% (95%CI: [94.9%-97.9%]) when compared to the Aptima SARS-CoV-2 assay. Conclusions The clinical performance of the MAX SARS-CoV-2 assay agreed with another sensitive EUA assay.

scholarly journals Rapid direct nucleic acid amplification test without RNA extraction for SARS-CoV-2 using a portable PCR thermocycler

2020 ◽  
Author(s):  
Soon Keong Wee ◽  
Suppiah Paramalingam Sivalingam ◽  
Eric Peng Huat Yap
Keyword(s):  
Nucleic Acid ◽  
Reverse Transcription ◽  
Rna Extraction ◽  
Cost Effective ◽  
Turnaround Time ◽  
Nucleic Acid Amplification ◽  
Detection Methods ◽  
N Gene ◽  
Direct Pcr ◽  
Viral Lysis

There is an ongoing worldwide coronavirus disease 2019 (Covid-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). At present, confirmatory diagnosis is by reverse transcription polymerase chain reaction (RT-PCR), typically taking several hours and requiring a molecular laboratory to perform. There is an urgent need for rapid, simplified and cost-effective detection methods. We have developed and analytically validated a protocol for direct rapid extraction-free PCR (DIRECT-PCR) detection of SARS-CoV-2 without the need for nucleic acid purification. As few as 6 RNA copies per reaction of viral nucleocapsid (N) gene from respiratory samples such as sputum and nasal exudate can be detected directly using our one-step inhibitor-resistant assay. The performance of this assay was validated on a commercially available portable PCR thermocycler. Viral lysis, reverse transcription, amplification and detection are achieved in a single-tube homogeneous reaction within 36 minutes. This minimized hands-on time, reduces turnaround-time for sample-to-result and obviates the need for RNA purification reagents. It could enable wider use of Covid-19 testing for diagnosis, screening and research in countries and regions where laboratory capabilities are limiting.

LABORATORY METHODS AND PREVALENCE OF SARS-COV-2 INFECTIONS IN THE 2ND SEMESTER OF 2021 IN THE EMERGENCY CLINICAL COUNTY HOSPITAL OF CONSTANTA

2021 ◽  
Author(s):  
Stoicescu Ramona ◽  
Stoicescu Razvan-Alexandru ◽  
Codrin Gheorghe ◽  
Schroder Verginica
Keyword(s):  
Respiratory Tract ◽  
Diagnostic Tests ◽  
Rapid Diagnostic Tests ◽  
Antigen Detection ◽  
Nucleic Acid Amplification ◽  
Rt Pcr ◽  
Laboratory Methods ◽  
Rapid Tests ◽  
Polymerase Chain ◽  
Tract Infections

"Diagnosing infections with SARS-CoV-2 is still of great interest due to the health and economic impact of COVID pandemic. The 4th wave of the COVID-19 pandemic is expected and is considered to be stronger and faster due to the dominance of Delta variant which is highly contagious [1]. SARS-CoV-2 also known as 2019-nCoV is one of the three coronaviruses (together with SARS-CoV or SARS-CoV1/Severe acute respiratory syndrome coronavirus), MERS-CoV /Middle East Respiratory Syndrome coronavirus) which can cause severe respiratory tract infections in humans [2]. Early diagnosis in COVID 19 infection is the key for preventing infection transmission in collectivity and proper medical care for the ill patients. Gold standard for diagnosing SARS-Co-V-2 infection according to WHO recommendation is using nucleic acid amplification tests (NAAT)/ reverse transcription polymerase chain reaction (RT-PCR). The search is on to develop reliable but less expensive and faster diagnostic tests that detect antigens specific for SARS-CoV-2 infection. Antigen-detection diagnostic tests are designed to directly detect SARSCoV-2 proteins produced by replicating virus in respiratory secretions so-called rapid diagnostic tests, or RDTs. The diagnostic development landscape is dynamic, with nearly a hundred companies developing or manufacturing rapid tests for SARS-CoV-2 antigen detection [3]. In the last 3 months our hospital introduced the antigen test or Rapid diagnostic tests (RDT) which detects the presence of viral proteins (antigens) expressed by the COVID-19 virus in a sample from the respiratory tract of a person. All RDT were confirmed next day with a RT-PCR. The number of positive cases detected during 3 months in our laboratory was 425. There were 326 positive tests in April, 106 positive tests in May and 7 positive tests in June. Compared with the number of positive tests in the 1st semester of 2021, the positive tests have significantly declined."

scholarly journals Rapid Direct Nucleic Acid Amplification Test without RNA Extraction for SARS-CoV-2 Using a Portable PCR Thermocycler

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 664 ◽  
Author(s):  
Soon Keong Wee ◽  
Suppiah Paramalingam Sivalingam ◽  
Eric Peng Huat Yap
Keyword(s):  
Nucleic Acid ◽  
Reverse Transcription ◽  
Rna Extraction ◽  
Cost Effective ◽  
Turnaround Time ◽  
Nucleic Acid Amplification ◽  
Detection Methods ◽  
N Gene ◽  
Direct Pcr ◽  
Viral Lysis

There is an ongoing worldwide coronavirus disease 2019 (Covid-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). At present, confirmatory diagnosis is by reverse transcription polymerase chain reaction (RT-PCR), typically taking several hours and requiring a molecular laboratory to perform. There is an urgent need for rapid, simplified, and cost-effective detection methods. We have developed and analytically validated a protocol for direct rapid extraction-free PCR (DIRECT-PCR) detection of SARS-CoV-2 without the need for nucleic acid purification. As few as six RNA copies per reaction of viral nucleocapsid (N) gene from respiratory samples such as sputum and nasal exudate can be detected directly using our one-step inhibitor-resistant assay. The performance of this assay was validated on a commercially available portable PCR thermocycler. Viral lysis, reverse transcription, amplification, and detection are achieved in a single-tube homogeneous reaction within 36 min. This minimizes hands-on time, reduces turnaround-time for sample-to-result, and obviates the need for RNA purification reagents. It could enable wider use of Covid-19 testing for diagnosis, screening, and research in countries and regions where laboratory capabilities are limiting.

scholarly journals Evaluation of Malaria Diagnostic Methods as a Key for Successful Control and Elimination Programs

2020 ◽  
Vol 5 (2) ◽  
pp. 102
Author(s):  
Afoma Mbanefo ◽  
Nirbhay Kumar
Keyword(s):  
Nucleic Acid ◽  
Diagnostic Tests ◽  
False Negative ◽  
Protein Detection ◽  
Diagnostic Methods ◽  
Nucleic Acid Amplification ◽  
World Health ◽  
Resource Limited ◽  
Successful Control ◽  
Polymerase Chain

Malaria is one of the leading causes of death worldwide. According to the World Health Organization’s (WHO’s) world malaria report for 2018, there were 228 million cases and 405,000 deaths worldwide. This paper reviews and highlights the importance of accurate, sensitive and affordable diagnostic methods in the fight against malaria. The PubMed online database was used to search for publications that examined the different diagnostic tests for malaria. Currently used diagnostic methods include microscopy, rapid diagnostic tests (RDT), and polymerase chain reaction (PCR). Upcoming methods were identified as loop-mediated isothermal amplification (LAMP), nucleic acid sequence-based amplification (NASBA), isothermal thermophilic helicase-dependent amplification (tHDA), saliva-based test for nucleic-acid amplification, saliva-based test for Plasmodium protein detection, urine malaria test (UMT), and transdermal hemozoin detection. RDT, despite its increasing false negative, is still the most feasible diagnostic test because it is easy to use, fast, and does not need expensive equipment. Noninvasive tests that do not require a blood sample, but use saliva or urine, are some of the recent tests under development that have the potential to aid malaria control and elimination. Emerging resistance to anti-malaria drugs and to insecticides used against vectors continues to thwart progress in controlling malaria. Therefore, future innovation will be required to enable the application of more sensitive and affordable methods in resource-limited settings.

scholarly journals Performance Evaluation of the SAMBA II SARS-CoV-2 Test for Point-of-Care Detection of SARS-CoV-2

2020 ◽  
Vol 59 (1) ◽  
pp. e01262-20 ◽  
Author(s):  
Sonny M. Assennato ◽  
Allyson V. Ritchie ◽  
Cesar Nadala ◽  
Neha Goel ◽  
Cuijuan Tie ◽  
...  
Keyword(s):  
Public Health ◽  
Infection Control ◽  
Patient Management ◽  
Clinical Performance ◽  
Point Of Care ◽  
Turnaround Time ◽  
Control Measures ◽  
Nucleic Acid Amplification ◽  
Analytical Sensitivity ◽  
Percent Agreement

ABSTRACTNucleic acid amplification for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in respiratory samples is the standard method for diagnosis. The majority of this testing is centralized and therefore has turnaround times of several days. Point-of-care (POC) testing with rapid turnaround times would allow more effective triage in settings where patient management and infection control decisions need to be made rapidly. The inclusivity and specificity of the Simple AMplification-Based Assay (SAMBA) II SARS-CoV-2 test were determined by both in silico analyses of the primers and probes and wet testing. The SAMBA II SARS-CoV-2 test was evaluated for performance characteristics. Clinical performance was evaluated in residual combined throat/nose swabs and compared to that of the Public Health England real-time PCR assay targeting the RdRp gene. The SAMBA II SARS-CoV-2 test has an analytical sensitivity of 250 copies/ml for detecting two regions of the genome (open reading frame 1ab [ORF1ab] and nucleocapsid protein [N]). The clinical performance was evaluated in 172 residual combined nose/throat swabs provided by the Clinical Microbiology and Public Health Laboratory, Addenbrooke’s Hospital, Cambridge (CMPHL), which showed an estimated positive percent agreement of 98.9% (95% confidence interval [CI], 93.83 to 99.97) and negative percent agreement of 96.4% (95% CI, 89.92 to 99.26) compared to testing by the CMPHL. The data show that the SAMBA II SARS-CoV-2 test performs equivalently to the centralized testing methods, but with a shorter turnaround time of 86 to 101 min. Point-of-care tests such as SAMBA should enable rapid patient management and effective implementation of infection control measures.

scholarly journals Study of Various Diagnostic Tests for COVID-19: A Review

2021 ◽  
Vol 1 (1) ◽  
pp. 153-162
Author(s):  
Manika Bhatia ◽  
Aditri ◽  
Shrreya Siingh ◽  
Yashaswy ◽  
Himanshu ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Early Diagnosis ◽  
Diagnostic Tests ◽  
Diagnostic Techniques ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Serological Testing ◽  
Diagnostic Kits ◽  
Exponential Increase ◽  
Entire World

The coronavirus disease of 2019 (COVID-19), a nightmare of this century, has become an ongoing global health emergency for the entire world. This dreadful disease is believed to have originated from China and has now spread worldwide. To date, more than 170 million people have been found affected by this virus, namely “severe acute respiratory syndrome coronavirus-2” (SARS-CoV-2). With the exponential increase in the patients affected by the SARS-CoV-2, the need for testing has also increased tremendously. Early diagnosis is essential to prevent the extensive spread of the disease because of the faster rate of infection. In this regard, various diagnostic techniques are employed for the detection of the infection in symptomatic and asymptomatic COVID-19 individuals. To provide diagnostic care for the control of the disease, various tests like serological testing, nucleic acid amplification test (NAAT), rapid antigen-based testing, and paper-based testing have been developed and are presently in good use. The present mini-review is an attempt to outline the currently available diagnostic kits for the detection of the SARS-CoV-2 causing COVID-19.

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