ArticleJournal of clinical virology : the official publication of the Pan American Society for Clinical Virology2020
Detection of SARS-COV N2 Gene: Very low amounts of viral RNA or false positive?
Article in Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
23 citing papers in PubMed, 1 synthesis or guideline pooled it, 34 citations in OpenAlex.
- The Diagnostic Accuracy of Xpert Xpress to SARS-CoV-2: A systematic review.Journal of virological methods · 2022Pooled it
- Review
- Wastewater analysis of Mpox virus in a city with low prevalence of Mpox disease: an environmental surveillance study.Lancet regional health. Americas · 2023Article
- Cycle Threshold Values as Indication of Increasing SARS-CoV-2 New Variants, England, 2020-2022.Emerging infectious diseases · 2023Article
- When rare becomes common: N2 gene-positive, E gene-negative SARS-CoV-2 PCR results between 2021 and 2022.Journal of clinical virology plus · 2023Article
- Cycle Threshold (Ct) Values of SARS-CoV-2 Detected with the GeneXpertCurrent issues in molecular biology · 2023Article
- SARS-CoV2 in public spaces in West London, UK during COVID-19 pandemic.BMJ open respiratory research · 2023Article
- Using Real-Time PCR Fluorescence Reaction Values to Improve SARS-CoV-2 Virus Detection and Benefit Clinical Decision-Making.Life (Basel, Switzerland) · 2023Article
- Article
- The Role of Surveillance Inspections in Reducing False-Positives of SARS-CoV-2 Omicron Variants during the COVID-19 Epidemic.The Canadian journal of infectious diseases & medical microbiology = Journal canadien des maladies infectieuses et de la microbiologie medicale · 2023Article
- How Significant Are Xpert Xpress SARS-CoV-2 Test Findings When Only an N2 Gene Is Detected?Diagnostics (Basel, Switzerland) · 2022Article
- Application of digital PCR to determine the reliability of Xpert Xpress SARS-CoV-2 assay with envelope (E) gene negative and nucleocapsid (N2) gene positive results.Diagnostic microbiology and infectious disease · 2022Article
- Unusual N Gene Dropout and Ct Value Shift in Commercial Multiplex PCR Assays Caused by Mutated SARS-CoV-2 Strain.Diagnostics (Basel, Switzerland) · 2022Article
- SARS-CoV2 RT-PCR assays: In vitro comparison of 4 WHO approved protocols on clinical specimens and its implications for real laboratory practice through variant emergence.Virology journal · 2022Article
- Performance Evaluation of Lateral Flow Assays for Coronavirus Disease-19 Serology.Clinics in laboratory medicine · 2022Review
- Article
- Performance evaluation of a new on-demand molecular test for the rapid identification of severe acute respiratory syndrome coronavirus 2 in pediatric and adult patients.Frontiers in microbiology · 2022Article
- SARS-CoV-2 viral load assessment in lung transplantation.Physiological research · 2021Article
- Molecular diagnosis of SARS-CoV-2 in seminal fluid.Journal of endocrinological investigation · 2021Article
- Development and validation of a new triplex real-time quantitative reverse Transcriptase-PCR assay for the clinical detection of SARS-CoV-2.Molecular and cellular probes · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe detection of a low amount of viral RNA is crucial to identify a SARS-CoV-2 positive individual harboring a low level of virus, especially during the convalescent period. However, the detection of one gene at high Cycle threshold (Ct) has to be interpreted with caution. In this study we address this specific issue and report our real-life experience. STUDY
designA total of 1639 nasopharyngeal swabs (NPS) were analyzed with Xpert® Xpress SARS-CoV-2. Positive samples showing high Ct values (Ct>35) were concentrated by centrifugation and re-tested with Cepheid or other methods (RealStar SARS-CoV2 RT-PCR, Altona Diagnostics; GeneFinder COVID-19 Plus RealAmp Kit, Elitech).
results1599 (97.5%) negative samples, 36 (2.3%) positive samples and 4 (0.2%) presumptive positive samples were detected. In 17 out of 36 positive patients, very low viral RNA copies were suspected since positivity was detected at high Ct. We confirmed positivity for patients who showed both E and N genes detected and for patients with only N detected but with Ct <39. On the contrary, samples with only gene N detected with Ct values >39 were found negative. NPS taken 24 hours after the first collection confirmed the negativity of the 12 samples. Clinical data sustained these results since only 2 of these 12 patients showed COVID-19-like symptoms.
conclusionsThese data support our consideration that detection of the N2 gene at high Ct needs to be interpreted with caution, suggesting that collaboration between virologists and clinicians is important for better understanding of results.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.