scholarly journals Comparison of three molecular diagnostic assays for SARS‐CoV‐2 detection: Evaluation of analytical sensitivity and clinical performance

2022 ◽  
Author(s):  
Ha Nui Kim ◽  
Soo‐Young Yoon ◽  
Chae Seung Lim ◽  
Jung Yoon
Keyword(s):  
Clinical Performance ◽  
Molecular Diagnostic ◽  
Analytical Sensitivity ◽  
Diagnostic Assays ◽  
Detection Evaluation

scholarly journals Comparison of Four Molecular In Vitro Diagnostic Assays for the Detection of SARS-CoV-2 in Nasopharyngeal Specimens

2020 ◽  
Author(s):  
Wei Zhen ◽  
Ryhana Manji ◽  
Elizabeth Smith ◽  
Gregory J. Berry
Keyword(s):  
Respiratory Infections ◽  
Clinical Performance ◽  
Control Measures ◽  
Molecular Diagnostic ◽  
Analytical Sensitivity ◽  
The Novel ◽  
Diagnostic Assays ◽  
Infection Control Measures ◽  
In Vitro Diagnostic

AbstractThe novel human coronavirus SARS-CoV-2 was first discovered in the city of Wuhan, Hubei province, China, causing an outbreak of pneumonia in January 2020. As of April 10, 2020, the virus has rapidly disseminated to over 200 countries and territories, causing more than 1.6 million confirmed cases of COVID-19 and 97,000 deaths worldwide. The clinical presentation of COVID-19 is fairly non-specific, and symptoms overlap with other seasonal respiratory infections concurrently circulating in the population. Further, it is estimated that up to 80% of infected individuals experience mild symptoms or are asymptomatic, confounding efforts to reliably diagnose COVID-19 empirically. To support infection control measures, there is an urgent need for rapid and accurate molecular diagnostics to identify COVID-19 positive patients. In the present study, we have evaluated the analytical sensitivity and clinical performance of four SARS-CoV-2 molecular diagnostic assays granted Emergency Use Authorization by the FDA using nasopharyngeal swabs from symptomatic patients. This information is crucial for both laboratories and clinical teams, as decisions on which testing platform to implement are made.

scholarly journals Comparison of Four Molecular In Vitro Diagnostic Assays for the Detection of SARS-CoV-2 in Nasopharyngeal Specimens

2020 ◽  
Vol 58 (8) ◽  
Author(s):  
Wei Zhen ◽  
Ryhana Manji ◽  
Elizabeth Smith ◽  
Gregory J. Berry
Keyword(s):  
New York ◽  
Respiratory Infections ◽  
Clinical Performance ◽  
Control Measures ◽  
Molecular Diagnostic ◽  
Analytical Sensitivity ◽  
Diagnostic Assays ◽  
Infection Control Measures ◽  
Diagnostic Panel

ABSTRACT Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the novel human coronavirus that causes coronavirus disease 2019 (COVID-19), was first discovered in December 2019 as the cause of an outbreak of pneumonia in the city of Wuhan, Hubei province, China. The clinical presentation of COVID-19 is fairly nonspecific, and symptoms overlap those of other seasonal respiratory infections concurrently circulating in the population. Furthermore, it is estimated that up to 80% of infected individuals experience mild symptoms or are asymptomatic, confounding efforts to reliably diagnose COVID-19 empirically. To support infection control measures, there is an urgent need for rapid and accurate molecular diagnostics to identify COVID-19-positive patients. In the present study, we evaluated the analytical sensitivity and clinical performance of the following four SARS-CoV-2 molecular diagnostic assays granted emergency use authorization by the FDA using nasopharyngeal swabs from symptomatic patients: the New York SARS-CoV-2 Real-time Reverse Transcriptase (RT)-PCR Diagnostic Panel (modified CDC) assay, the Simplexa COVID-19 Direct (Diasorin Molecular) assay, GenMark ePlex SARS-CoV-2 (GenMark) assay, and the Hologic Panther Fusion SARS-CoV-2 (Hologic) assay. This information is crucial for both laboratories and clinical teams as decisions on which testing platform to implement are made.

scholarly journals Clinical Evaluation of Three Sample-to-Answer Platforms for Detection of SARS-CoV-2

2020 ◽  
Vol 58 (8) ◽  
Author(s):  
Wei Zhen ◽  
Elizabeth Smith ◽  
Ryhana Manji ◽  
Deborah Schron ◽  
Gregory J. Berry
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Drug Administration ◽  
Clinical Evaluation ◽  
Limit Of Detection ◽  
Clinical Performance ◽  
Molecular Diagnostic ◽  
Analytical Sensitivity ◽  
Reference Standard ◽  
Slight Improvement ◽  
Percent Agreement

ABSTRACT Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has now spread across the globe. As part of the worldwide response, many molecular diagnostic platforms have been granted emergency use authorization (EUA) by the Food and Drug Administration (FDA) to identify SARS-CoV-2 positive patients. Our objective was to evaluate three sample-to-answer molecular diagnostic platforms (Cepheid Xpert Xpress SARS-CoV-2 [Xpert Xpress], Abbott ID NOW COVID-19 [ID NOW], and GenMark ePlex SARS-CoV-2 Test [ePlex]) to determine analytical sensitivity, clinical performance, and workflow for the detection of SARS-CoV-2 in nasopharyngeal swabs from 108 symptomatic patients. We found that Xpert Xpress had the lowest limit of detection (100% detection at 100 copies/ml), followed by ePlex (100% detection at 1,000 copies/ml), and ID NOW (20,000 copies/ml). Xpert Xpress also had highest positive percent agreement (PPA) compared to our reference standard (98.3%) followed by ePlex (91.4%) and ID NOW (87.7%). All three assays showed 100% negative percent agreement (NPA). In the workflow analysis, ID NOW produced the lowest time to result per specimen (∼17 min) compared to Xpert Xpress (∼46 min) and ePlex (∼1.5 h), but what ID NOW gained in rapid results, it lost in analytical and clinical performance. ePlex had the longest time to results and showed a slight improvement in PPA over ID NOW. Information about the clinical and analytical performance of these assays, as well as workflow, will be critical in making informed and timely decisions on testing platforms.

scholarly journals Analysis and phylogenetic comparisons of full-length VP2 genes of the 24 bluetongue virus serotypes

2007 ◽  
Vol 88 (2) ◽  
pp. 621-630 ◽  
Author(s):  
S. Maan ◽  
N. S. Maan ◽  
A. R. Samuel ◽  
S. Rao ◽  
H. Attoui ◽  
...  
Keyword(s):  
Bluetongue Virus ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Full Length ◽  
Molecular Diagnostic ◽  
Mammalian Host ◽  
Reading Frame ◽  
Diagnostic Assays ◽  
Primary Determinant ◽  
Serotype Identification

The outer capsid protein VP2 of Bluetongue virus (BTV) is a target for the protective immune response generated by the mammalian host. VP2 contains the majority of epitopes that are recognized by neutralizing antibodies and is therefore also the primary determinant of BTV serotype. Full-length cDNA copies of genome segment 2 (Seg-2, which encodes VP2) from the reference strains of each of the 24 BTV serotypes were synthesized, cloned and sequenced. This represents the first complete set of full-length BTV VP2 genes (from the 24 serotypes) that has been analysed. Each Seg-2 has a single open reading frame, with short inverted repeats adjacent to conserved terminal hexanucleotide sequences. These data demonstrated overall inter-serotype variations in Seg-2 of 29 % (BTV-8 and BTV-18) to 59 % (BTV-16 and BTV-22), while the deduced amino acid sequence of VP2 varied from 22.4 % (BTV-4 and BTV-20) to 73 % (BTV-6 and BTV-22). Ten distinct Seg-2 lineages (nucleotypes) were detected, with greatest sequence similarities between those serotypes that had previously been reported as serologically ‘related’. Fewer similarities were observed between different serotypes in regions of VP2 that have been reported as antigenically important, suggesting that they may play a role in the neutralizing antibody response. The data presented form an initial basis for BTV serotype identification by sequence analyses and comparison of Seg-2, and for development of molecular diagnostic assays for individual BTV serotypes (by RT-PCR).

scholarly journals Use of Quantitative Molecular Diagnostic Assays to Investigate Fusarium Dry Rot in Potato Stocks and Soil

2005 ◽  
Vol 95 (12) ◽  
pp. 1462-1471 ◽  
Author(s):  
D. W. Cullen ◽  
I. K. Toth ◽  
Y. Pitkin ◽  
N. Boonham ◽  
K. Walsh ◽  
...  
Keyword(s):  
Control Strategies ◽  
Disease Incidence ◽  
Harvest Date ◽  
Molecular Diagnostic ◽  
Enzyme Linked Immunosorbent Assay ◽  
Potato Seed ◽  
Fusarium Spp ◽  
Dry Rot ◽  
Diagnostic Assays ◽  
Final Harvest

Specific and sensitive quantitative diagnostics, based on real-time (TaqMan) polymerase chain reaction (PCR) and PCR enzyme-linked immunosorbent assay, were developed to detect dry-rot-causing Fusarium spp. (F. avenaceum, F. coeruleum, F. culmorum, and F. sulphureum). Each assay detected Fusarium spp. on potato seed stocks with equal efficiency. Four potato stocks, sampled over two seed generations from Scottish stores, were contaminated with F. avenaceum, F. sulphureum, F. culmorum, F. coeruleum or a combination of species, and there was a general trend towards increased Fusarium spp. contamination in the second generation of seed sampled. F. sulphureum and F. coeruleum caused significantly (P < 0.05) more disease in storage than the other species when disease-free tubers of potato cvs. Spunta and Morene were inoculated at a range of inoculum concentrations (0, 104, 105, and 106 conidia/ml). Increased DNA levels were correlated with increased disease severity between 8 and 12 weeks of storage. The threshold inoculum levels resulting in significant disease development on both cultivars were estimated to be 104 conidia/ml for F. sulphureum and 105 conidia/ml for F. coeruleum. To study the effect of soil infestation and harvest date on disease incidence, seed tubers of cvs. Morene and Spunta were planted in a field plot artificially infested with the four Fusarium spp. F. culmorum and F. sulphureum were detected in soil taken from these plots at harvest, and F. sulphureum DNA levels increased significantly (P < 0.05) at the final harvest. All four Fusarium spp. were detected in progeny tubers. There was a trend toward higher levels of F. culmorum detected in progeny tubers at the earliest harvest date, and higher levels of F. sulphureum at the final harvest. The use of diagnostic assays to detect fungal storage rot pathogens and implications for disease control strategies are discussed.

scholarly journals Most but not all laboratories can detect the recently emerged Neisseria gonorrhoeae porA mutants – results from the QCMD 2013 N. gonorrhoeae external quality assessment programme

2014 ◽  
Vol 19 (8) ◽  
Author(s):  
D Luijt ◽  
C Di Lorenzo ◽  
A M van Loon ◽  
M Unemo
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Quality Assessment ◽  
External Quality Assessment ◽  
False Negative ◽  
Molecular Diagnostic ◽  
External Quality ◽  
Diagnostic Assays ◽  
Assessment Programme ◽  
Negative Results ◽  
False Negative Results

We describe the results of the Quality Control for Molecular Diagnostics 2013 Neisseria gonorrhoeae external quality assessment programme that included an N. gonorrhoeae strain harbouring an N. meningitidis porA gene which causes false-negative results in molecular diagnostic assays targeting the gonococcal porA pseudogene. Enhanced awareness of the international transmission of such gonococcal strains is needed to avoid false-negative results in both in-house and commercial molecular diagnostic assays used in laboratories worldwide, but particularly in Europe.

scholarly journals Triage of hrHPV-positive women: comparison of two commercial methylation-specific PCR assays

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Carolin Dippmann ◽  
Martina Schmitz ◽  
Kristina Wunsch ◽  
Stefanie Schütze ◽  
Katrin Beer ◽  
...  
Keyword(s):  
Dna Methylation ◽  
False Positive ◽  
Pap Smear ◽  
Intraepithelial Neoplasia ◽  
Molecular Diagnostic ◽  
Cervical Lesions ◽  
Detection Rates ◽  
Diagnostic Assays ◽  
Specific Pcr

Abstract Aim High-risk human papillomavirus (hrHPV)-based screening is becoming increasingly important, either by supplementing or replacing the traditional cytology-based cervical Pap smear. However, hrHPV screening lacks specificity, because it cannot differentiate between transient virus infection and clinically relevant hrHPV-induced disease. Therefore, reliable triage methods are needed for the identification of HPV-positive women with cervical intraepithelial neoplasia (CIN) in need of treatment. Promising tools discussed for the triage of these patients are molecular diagnostic tests based on epigenetic markers. Here, we compare the performance of two commercially available DNA methylation-based diagnostic assays—GynTect® and the QIAsure Methylation Test—in physician-taken cervical scrapes from 195 subjects. Findings Both GynTect® and the QIAsure Methylation Test detected all cervical carcinoma and carcinoma in situ (CIS). The differences observed in the detection rates between both assays for the different grades of cervical lesions (QIAsure Methylation Test: CIN1 26.7%, CIN2 27.8% and CIN3 74.3%; GynTect®: CIN1 13.3%, CIN2 33.3% and CIN3 60%) were not significant. Concerning the false-positive rates, significant differences were evident. For the healthy (NILM) hrHPV-positive group, the false-positive rates were 5.7% for GynTect® and 26.4% for QIAsure Methylation Test (p = 0.003) and for the NILM hrHPV-negative group 2.2% vs. 23.9% (p = 0.006), respectively. When considering hrHPV-positive samples only for comparison (n = 149), GynTect® delivered significantly higher specificity compared to the QIAsure Methylation Test for CIN2 + (87.6% vs. 67.4% (p < 0.001)) and CIN3 + (84.1% vs. 68.2% (p = 0.002)). Overall our findings suggest that DNA methylation-based tests are suitable for the triage of hrHPV-positive women. With the goal to provide a triage test that complements the limited specificity of HPV testing in HPV-based screening, GynTect® may be preferable, due to its higher specificity for CIN2+ or CIN3+ .

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