scholarly journals The Prognostic Value of an RT-PCR Test for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Is Contingent on Timing across Disease Time Course in addition to Assay Sensitivity

2022 ◽  
Vol 24 (1) ◽  
pp. 101-103 ◽  
Author(s):  
Jeffrey P. Townsend ◽  
Chad R. Wells
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Prognostic Value ◽  
Time Course ◽  
Rt Pcr ◽  
Assay Sensitivity ◽  
Pcr Test

scholarly journals Antibody response and viraemia during the course of severe acute respiratory syndrome (SARS)-associated coronavirus infection

2004 ◽  
Vol 53 (5) ◽  
pp. 435-438 ◽  
Author(s):  
Weijun Chen ◽  
Zuyuan Xu ◽  
Jingsong Mu ◽  
Ling Yang ◽  
Haixue Gan ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Antibody Response ◽  
Time Course ◽  
Recovery Phase ◽  
Antibody Responses ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Blood Samples ◽  
Convalescent Phase ◽  
Coronavirus Infection

To understand the time-course of viraemia and antibody responses to severe acute respiratory syndrome-associated coronavirus (SARS-CoV), RT-PCR and ELISA were used to assay 376 blood samples from 135 SARS patients at various stages of the illness, including samples from patients who were in their early convalescent phase. The results showed that IgM antibodies decreased and became undetectable 11 weeks into the recovery phase. IgG antibodies, however, remained detectable for a period beyond 11 weeks and were found in 100 % of patients in the early convalescent phase. SARS-CoV viraemia mainly appeared 1 week after the onset of illness and then decreased over a period of 1 month, becoming undetectable in the blood samples of the convalescent patients. At the peak of viraemia, viral RNA was detectable in 75 % of blood samples from patients who were clinically diagnosed with SARS 1 or 2 weeks before the test.

scholarly journals Agile design and development of a high throughput cobas® SARS-CoV-2 RT-PCR diagnostic test

2021 ◽  
Author(s):  
Chitra Manohar ◽  
Jingtao Sun ◽  
Peter Schlag ◽  
Chris Santini ◽  
Marcel Fontecha ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Rapid Development ◽  
Diagnostic Testing ◽  
In Silico Analysis ◽  
Rt Pcr ◽  
Assay Sensitivity ◽  
Agile Design ◽  
Assay Design ◽  
Pcr Test ◽  
Dual Target

Diagnostic testing is essential for management of the COVID-19 pandemic. An agile assay design methodology, optimized for the cobas® 6800/8800 system, was used to develop a dual-target, qualitative SARS-CoV-2 RT-PCR test using commercially available reagents and existing sample processing and thermocycling profiles. The limit of detection was 0.004 to 0.007 TCID50/mL for USA-WA1/2020. Assay sensitivity was confirmed for SARS-CoV-2 variants Alpha, Beta, Gamma, Delta and Kappa. The coefficients of variation of the cycle threshold number (Ct) were between 1.1 and 2.2%. There was no difference in Ct using nasopharyngeal compared to oropharyngeal swabs in universal transport medium (UTM). A small increase in Ct was observed with specimens collected in cobas® PCR medium compared to UTM. In silico analysis indicated that the dual-target test is capable of detecting all >1,800,000 SARS-CoV-2 sequences in the GISAID database. Our agile assay design approach facilitated rapid development and deployment of this SARS-CoV-2 RT-PCR test.

Evaluation of the consistency of RT-PCR test results in nasopharyngeal and fecal specimens in patients with Covid-19 disease with gastrointestinal symptoms

2021 ◽  
Vol 15 (6) ◽  
pp. 1843-1846
Author(s):  
Mohammad Ebrahim Ghamarchehreh ◽  
Mohammad Mehdi Jahani ◽  
Zahra Nourollahzadeh
Keyword(s):  
Infectious Disease ◽  
Severe Acute Respiratory Syndrome ◽  
Gastrointestinal Symptoms ◽  
Taqman Probe ◽  
Clinical Samples ◽  
Test Results ◽  
Rt Pcr ◽  
Specific Primers ◽  
Pcr Method ◽  
Pcr Test

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Addition to respiratory manifestations, gastrointestinal symptoms have been observed in some patients with COVID-19. The aim of the present study was to investigate the simultaneous diagnosis of SARS-CoV-2 RNA by RT-PCR in nasopharyngeal and fecal specimens of patients with covid-19 with gastrointestinal symptoms. In the present study, 100 patients with COVID-19 disease with gastrointestinal symptoms were included. Isolation of viral RNA in nasopharyngeal and fecal samples performed using specific laboratory kits. Detection of COVID-19 in clinical samples conducted using TaqMan-probe Real Time PCR method with specific primers and probes (Pishtaz Teb RT-PCR kit, Iran). PCR test results showed that in 21% of patients with positive nasopharyngeal test, SARS ‐ CoV ‐ 2 RNA was detected. As a result, the compatibility of PCR test in the diagnosis of Covid-19 virus between nasopharyngeal and fecal results was 21%. Keywords: Covid-19, nasopharyngeal, fecal specimens, RT-PCR

scholarly journals Evaluation of Antibody Response in Symptomatic and Asymptomatic COVID-19 Patients and Diagnostic Assessment of New IgM/IgG ELISA Kits

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 161
Author(s):  
Hadeel T. Al-Jighefee ◽  
Hadi M. Yassine ◽  
Maryam A. Al-Nesf ◽  
Ali A. Hssain ◽  
Sara Taleb ◽  
...  
Keyword(s):  
Immune Response ◽  
Severe Acute Respiratory Syndrome ◽  
Antibody Response ◽  
Diagnostic Assessment ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Serum Samples ◽  
Time Intervals ◽  
Low Sensitivity ◽  
Pcr Test

This study aims to study the immune response and evaluate the performances of four new IgM and five IgG enzyme-linked immunosorbent assay (ELISA) kits for detecting anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies against different antigens in symptomatic and asymptomatic coronavirus disease 2019 (COVID-19) patients. A total of 291 samples collected from symptomatic and asymptomatic RT–PCR-confirmed patients were used to evaluate the ELISA kits’ performance (EDI, AnshLabs, DiaPro, NovaLisa, and Lionex). The sensitivity was measured at three different time-intervals post symptoms onset or positive SARS-CoV-2 RT–PCR test (≤14, 14–30, >30 days). The specificity was investigated using 119 pre-pandemic serum samples. The sensitivity of all IgM kits gradually decreased with time, ranging from 48.7% (EDI)–66.4% (Lionex) at ≤14 days, 29.1% (NovaLisa)–61.8% (Lionex) at 14–30 days, and 6.0% (AnshLabs)–47.9% (Lionex) at >30 days. The sensitivity of IgG kits increased with time, peaking in the latest interval (>30 days) at 96.6% (Lionex). Specificity of IgM ranged from 88.2% (Lionex)–99.2% (EDI), while IgG ranged from 75.6% (DiaPro)–98.3% (Lionex). Among all RT–PCR-positive patients, 23 samples (7.9%) were seronegative by all IgG kits, of which only seven samples (30.4%) had detectable IgM antibodies. IgM assays have variable and low sensitivity, thus considered a poor marker for COVID-19 diagnosis. IgG assays can miss at least 8% of RT–PCR-positive cases.

scholarly journals Multicentre comparison of quantitative PCR-based assays to detect SARS-CoV-2, Germany, March 2020

2020 ◽  
Vol 25 (24) ◽  
Author(s):  
Maximilian Muenchhoff ◽  
Helga Mairhofer ◽  
Hans Nitschko ◽  
Natascha Grzimek-Koschewa ◽  
Dieter Hoffmann ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Quantitative Pcr ◽  
Clinical Management ◽  
False Negative ◽  
Test Results ◽  
Rt Pcr ◽  
Diagnostic Pcr ◽  
Pcr Assays ◽  
Pcr Test ◽  
False Negative Test

Containment strategies and clinical management of coronavirus disease (COVID-19) patients during the current pandemic depend on reliable diagnostic PCR assays for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we compare 11 different RT-PCR test systems used in seven diagnostic laboratories in Germany in March 2020. While most assays performed well, we identified detection problems in a commonly used assay that may have resulted in false-negative test results during the first weeks of the pandemic.

1089: Prognostic Value of Molecular Staging of Bladder Cancer with RT -PCR Assay for KRT20: Results at 5 Year-Follow-up

2007 ◽  
Vol 177 (4S) ◽  
pp. 360-360
Author(s):  
Ana Agud ◽  
Maria J. Ribal ◽  
Lourdes Mengual ◽  
Mercedes Marin-Aguilera ◽  
Laura Izquierdo ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Prognostic Value ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Molecular Staging

scholarly journals Proposal of RT-PCR–Based Mass Population Screening for Severe Acute Respiratory Syndrome Coronavirus 2 (Coronavirus Disease 2019)

2020 ◽  
Vol 22 (10) ◽  
pp. 1294-1299 ◽  
Author(s):  
Nikhil S. Sahajpal ◽  
Ashis K. Mondal ◽  
Allan Njau ◽  
Sudha Ananth ◽  
Kimya Jones ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Population Screening ◽  
Rt Pcr

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.

scholarly journals The role of CT imaging for management of COVID-19 in epidemic area: early experience from a University Hospital

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vikram rao Bollineni ◽  
Koenraad Hans Nieboer ◽  
Seema Döring ◽  
Nico Buls ◽  
Johan de Mey
Keyword(s):  
Ct Scan ◽  
Predictive Value ◽  
Ct Imaging ◽  
Chest Ct ◽  
University Hospital ◽  
Rt Pcr ◽  
Ct Findings ◽  
Epidemic Area ◽  
Chest Ct Scan ◽  
Pcr Test

Abstract Background To evaluate the clinical value of the chest CT scan compared to the reference standard real-time polymerase chain reaction (RT-PCR) in COVID-19 patients. Methods From March 29th to April 15th of 2020, a total of 240 patients with respiratory distress underwent both a low-dose chest CT scan and RT-PCR tests. The performance of chest CT in diagnosing COVID-19 was assessed with reference to the RT-PCR result. Two board-certified radiologists (mean 24 years of experience chest CT), blinded for the RT-PCR result, reviewed all scans and decided positive or negative chest CT findings by consensus. Results Out of 240 patients, 60% (144/240) had positive RT-PCR results and 89% (213/240) had a positive chest CT scans. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of chest CT in suggesting COVID-19 were 100% (95% CI: 97–100%, 144/240), 28% (95% CI: 19–38%, 27/240), 68% (95% CI: 65–70%) and 100%, respectively. The diagnostic accuracy of the chest CT suggesting COVID-19 was 71% (95% CI: 65–77%). Thirty-three patients with positive chest CT scan and negative RT-PCR test at baseline underwent repeat RT-PCR assay. In this subgroup, 21.2% (7/33) cases became RT-PCR positive. Conclusion Chest CT imaging has high sensitivity and high NPV for diagnosing COVID-19 and can be considered as an alternative primary screening tool for COVID-19 in epidemic areas. In addition, a negative RT-PCR test, but positive CT findings can still be suggestive of COVID-19 infection.

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