scholarly journals Influence of Illness Duration on the Sensitivity and Specificity of Influenza Antigen Testing： A Prospective Observational Study Using Real-time PCR

2021 ◽  
Vol 95 (1) ◽  
pp. 9-16
Author(s):  
Yusaku AKASH ◽  
Hiromichi SUZUKI ◽  
Yuto TAKEUCH ◽  
Atsuo UEDA ◽  
Yumi HIROSE ◽  
...  
Keyword(s):  
Observational Study ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Prospective Observational Study ◽  
Illness Duration ◽  
Antigen Testing

scholarly journals Diagnosing SARS-CoV-2 with Antigen Testing, Transcription-Mediated Amplification and Real-Time PCR

2021 ◽  
Vol 10 (11) ◽  
pp. 2404
Author(s):  
Sascha Dierks ◽  
Oliver Bader ◽  
Julian Schwanbeck ◽  
Uwe Groß ◽  
Michael Weig ◽  
...  
Keyword(s):  
Real Time ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Gold Standard ◽  
Latent Class ◽  
Antigen Assay ◽  
Low Prevalence ◽  
Antigen Testing ◽  
Positive Results ◽  
Higher Sensitivity

This study was performed as a head-to-head comparison of the performance characteristics of (1) two SARS-CoV-2-specific rapid antigen assays with real-time PCR as gold standard as well as (2) a fully automated high-throughput transcription-mediated amplification (TMA) assay and real-time PCR in a latent class analysis-based test comparison without a gold standard with several hundred samples in a low prevalence “real world” setting. Recorded sensitivity and specificity of the NADAL and the LumiraDx antigen assays and the Hologic Aptima SARS-CoV-2 TMA assay were 0.1429 (0.0194, 0.5835), 0.7644 (0.7016, 0.8174), and 0.7157 (0, 1) as well as 0.4545 (0.2022, 0.7326), 0.9954 (0.9817, 0.9988), and 0.9997 (not estimable), respectively. Agreement kappa between the positive results of the two antigen-based assays was 0.060 (0.002, 0.167) and 0.659 (0.492, 0.825) for TMA and real-time PCR. Samples with low viral load as indicated by cycle threshold (Ct) values > 30 were generally missed by both antigen assays, while 1:10 pooling suggested higher sensitivity of TMA compared to real-time PCR. In conclusion, both sensitivity and specificity speak in favor of the use of the LumiraDx rather than the NADAL antigen assay, while TMA results are comparably as accurate as PCR, when applied in a low prevalence setting.

scholarly journals A Prospective Observational Study of Mycophenolate Mofetil Treatment in Progressive Diffuse Cutaneous Systemic Sclerosis of Recent Onset

2012 ◽  
Vol 39 (6) ◽  
pp. 1241-1247 ◽  
Author(s):  
FABIAN A. MENDOZA ◽  
SARAH J. NAGLE ◽  
JASON B. LEE ◽  
SERGIO A. JIMENEZ
Keyword(s):  
Mycophenolate Mofetil ◽  
Systemic Sclerosis ◽  
Observational Study ◽  
Pulmonary Function ◽  
Real Time ◽  
Real Time Pcr ◽  
Prospective Observational Study ◽  
Pulmonary Function Tests ◽  
Recent Onset ◽  
Skin Biopsies

Objective.A prospective observational study of mycophenolate mofetil (MMF) treatment in patients with diffuse progressive cutaneous systemic sclerosis (SSc) of recent onset.Methods.Twenty-five previously untreated consecutive patients with recent-onset (< 24 mo) diffuse progressive cutaneous SSc received MMF as the only disease-modifying therapy. Modified Rodnan skin score (mRSS) and affected body surface area (BSA) were compared from initiation of MMF to study end. Pulmonary function tests performed at the same institution before therapy and at study end were available in 15 patients. Histopathology and real-time PCR assessment of fibrosis-related gene expression were performed before and after treatment in skin biopsies from 3 patients.Results.At 18.2 ± 8.73 months of MMF therapy (median 2000 mg/day) the mRSS decreased from 24.56 ± 8.62 to 14.52 ± 10.9 (p = 0.0004) and the affected BSA from 36% ± 16% to 14% ± 13.3% (p = 0.00001). Pulmonary function tests remained stable from initiation of MMF to the end of the study. Skin histopathology showed a remarkable reduction in accumulation of fibrotic tissue. Real-time PCR of skin biopsies demonstrated a marked decrease in expression of fibrosis-related genes.Conclusion.Patients with diffuse progressive cutaneous SSc of recent onset treated with MMF experienced marked improvement in skin involvement and stabilization of pulmonary function. Skin biopsies from 3 patients demonstrated histopathological improvement and decreased expression of fibrosis-related genes.

scholarly journals Persistence of SARS-CoV-2 Viral RNA in Nasopharyngeal Swabs after Death: An Observational Study

2021 ◽  
Vol 9 (4) ◽  
pp. 800
Author(s):  
Francesca Servadei ◽  
Silvestro Mauriello ◽  
Manuel Scimeca ◽  
Bartolo Caggiano ◽  
Marco Ciotti ◽  
...  
Keyword(s):  
Viral Load ◽  
Observational Study ◽  
Real Time ◽  
Real Time Pcr ◽  
Pcr Detection ◽  
Viral Rna ◽  
Clinical Documentation ◽  
Post Mortem ◽  
Medical Assistance ◽  
Time Points

The aim of this study was to investigate the persistence of SARS-CoV-2 in post-mortem swabs of subjects who died from SARS-CoV-2 infection. The presence of the virus was evaluated post-mortem from airways of 27 SARS-CoV-2 positive patients at three different time points (T1 2 h; T2 12 h; T3 24 h) by real-time PCR. Detection of antibodies to SARS-CoV-2 was performed by Maglumi 2019-nCoV IgM/IgG chemiluminescence assay. SARS-CoV-2 viral RNA was still detectable in 70.3% of cases within 2 h after death and in 66,6% of cases up to 24 h after death. Our data showed an increase of the viral load in 78,6% of positive individuals 24 h post-mortem (T3) in comparison to that evaluated 2 h after death (T1). Noteworthy, we detected a positive T3 post-mortem swab (24 h after death) from 4 subjects who were negative at T1 (2 h after death). The results of our study may have an important value in the management of deceased subjects not only with a suspected or confirmed diagnosis of SARS-CoV-2, but also for unspecified causes and in the absence of clinical documentation or medical assistance.

scholarly journals Evaluation of the New BD Max GC Real-Time PCR Assay, Analytically and Clinically as a Supplementary Test for the BD ProbeTec GC Qx Amplified DNA Assay, for Molecular Detection of Neisseria gonorrhoeae

2015 ◽  
Vol 53 (12) ◽  
pp. 3935-3937 ◽  
Author(s):  
Daniel Golparian ◽  
Stina Boräng ◽  
Martin Sundqvist ◽  
Magnus Unemo
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Molecular Detection ◽  
Analytical Sensitivity ◽  
Pcr Assay ◽  
Content Type ◽  
Dna Assay ◽  
Supplementary Test

The new BD Max GC real-time PCR assay showed high clinical and analytical sensitivity and specificity. It can be an effective and accurate supplementary test for the BD ProbeTec GC Qx amplified DNA assay, which had suboptimal specificity, and might also be used for initial detection ofNeisseria gonorrhoeae.

scholarly journals Comparison of the sensitivity and specificity of real-time PCR and in situ hybridization in HPV16 and 18 detection in archival cervical cancer specimens

2012 ◽  
Vol 50 (2) ◽  
pp. 239-247 ◽  
Author(s):  
Beata Biesaga ◽  
Sława Szostek ◽  
Małgorzata Klimek ◽  
Jerzy Jakubowicz ◽  
Joanna Wysocka
Keyword(s):  
Cervical Cancer ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Real Time Pcr

scholarly journals Triplex Real-Time PCR without DNA Extraction for the Monitoring of Meningococcal Disease

Diagnostics ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 58 ◽  
Author(s):  
Melissa Whaley ◽  
Laurel Jenkins ◽  
Fang Hu ◽  
Alexander Chen ◽  
Seydou Diarra ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Real Time ◽  
Dna Extraction ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Limit Of Detection ◽  
Detection Range ◽  
Clinical Specimens ◽  
Large Numbers ◽  
Pcr Assays

Detection of Neisseria meningitidis has become less time- and resource-intensive with a monoplex direct real-time PCR (drt-PCR) to amplify genes from clinical specimens without DNA extraction. To further improve efficiency, we evaluated two triplex drt-PCR assays for the detection of meningococcal serogroups AWX and BCY. The sensitivity and specificity of the triplex assays were assessed using 228 cerebrospinal fluid (CSF) specimens from meningitis patients and compared to the monoplex for six serogroups. The lower limit of detection range for six serogroup-specific drt-PCR assays was 178–5264 CFU/mL by monoplex and 68–2221 CFU/mL by triplex. The triplex and monoplex showed 100% agreement for six serogroups and the triplex assays achieved similar sensitivity and specificity estimates as the monoplex drt-PCR assays. Our triplex method reduces the time and cost of processing CSF specimens by characterizing six serogroups with only two assays, which is particularly important for testing large numbers of specimens for N. meningitidis surveillance.

scholarly journals Pooling of interdigital swab samples for PCR detection of virulent Dichelobacter nodosus

2017 ◽  
Vol 30 (2) ◽  
pp. 205-210 ◽  
Author(s):  
Deborah Greber ◽  
Iwan Locher ◽  
Peter Kuhnert ◽  
Marc-André Butty ◽  
Kerstin Holdener ◽  
...  
Keyword(s):  
Real Time ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Substantial Reduction ◽  
Control Program ◽  
Foot Rot ◽  
Dichelobacter Nodosus ◽  
Foot Disease ◽  
Development And Validation ◽  
Adequate Method

Virulent ovine foot rot is a contagious foot disease. Given the development and validation of a real-time PCR to detect Dichelobacter nodosus isolates that contain the virulence-associated protease genes aprV2 and aprB2, the diagnosis of foot rot has made considerable progress. We evaluated pooling methods to reduce the number of samples during a foot rot control program. Samples of individual feet were compared to a 4-feet sample of the same sheep. All further analyses based on 4-feet samples (pools-of-5 and pools-of-10 4-feet samples) were compared to samples of individual sheep, and a risk-based herd sampling was evaluated and compared to the whole flock. The sensitivity and specificity of the 4-feet samples for detection of aprV2-positive strains was 93.8% (CI: 87.6–97.5%) and 98.3% (CI: 96.5–99.3%), respectively. The sensitivity and specificity of the pools-of-10 was 86.7% (CI: 78.4–92.7%) and 100.0% (CI: 97.4–100%), respectively. Pools-of-5 were not significantly more sensitive than pools-of-10. The pooling of 4 individual foot samples into one 4-feet sample is an adequate method to reduce the number of samples of individual sheep. The sensitivity of pools-of-5 and pools-of-10 is too imprecise for a control program. Risk-based sampling allowed for a substantial reduction of samples to be tested, had a sensitivity of 95.8% (CI: 78.9–99.9%) and specificity of 100.0% (CI: 88.1–100.0%) when determining the foot rot flock status, and represents an adequate methodology to predict within-flock freedom from infection.

scholarly journals Evaluation of Enzyme Immunoassays and Real-Time PCR for Detecting Shiga Toxin-Producing Escherichia coli in Southern Alberta, Canada

2015 ◽  
Vol 53 (3) ◽  
pp. 1019-1023 ◽  
Author(s):  
Linda Chui ◽  
Laura Patterson-Fortin ◽  
Julie Kuo ◽  
Vincent Li ◽  
Valerie Boras
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Shiga Toxin ◽  
Real Time Pcr ◽  
Content Type ◽  
Enzyme Immunoassays ◽  
Southern Alberta

Two immunoassays (Shiga Toxin Chek and Shiga Toxin Quik Chek) and real-time PCR were used to detect Shiga toxin-producingEscherichia coli. For enriched culture, the sensitivity and specificity of the three methods ranged from 80.0% to 98.2% and 98.0% to 100.0%, respectively. STEC isolates were identified in 2.6% of the 784 samples.

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