scholarly journals The Value of Rapid Antigen Tests to Identify Carriers of Viable SARS-CoV-2

2021 ◽  
Author(s):  
Elena V. Shidlovskaya ◽  
Nadezhda A. Kuznetsova ◽  
Elizaveta V. Divisenko ◽  
Maria A. Nikiforova ◽  
Andrei E. Siniavin ◽  
...  
Keyword(s):  
Cell Culture ◽  
Diagnostic Value ◽  
Healthy People ◽  
Rt Pcr ◽  
Culture Sensitivity ◽  
Rapid Tests ◽  
Antigen Tests

AbstractThe search for effective methods to detect patients who excrete a viable virus is one of the urgent tasks of modern biomedicine. In the present study, we examined the diagnostic value of two antigen tests BIOCREDIT COVID-19 Ag (RapiGEN Inc., Korea) and SGTI-flex COVID-19 Ag (Sugentech Inc., Korea) for their diagnostic value in identifying patients who excrete viable SARS-CoV-2. As part of the study, we examined samples from 106 patients who had just been admitted to the hospital, who had undergone quantitative RT-PCR and assessment of viability of SARS-CoV-2 using cell culture. Sensitivity was 0.786 (0.492–0.953) for SGTI-flex COVID-19 Ag and 1 (0.768– 1) for Biocredit COVID-19 Ag. Specificity of rapid tests was significantly higher than that of RT-PCR and was 0.663 (0.557–0.758) and 0.674 (0.568–0.768) for SGTI-flex COVID-19 Ag and Biocredit COVID-19 Ag versus 0.304 (0.213–0.409) obtained for PCR. Thus, for tasks of identifying viable SARS-CoV-2 during screening of conditionally healthy people, as well as monitoring those quarantined, rapid tests show significantly better results.

scholarly journals The Value of Rapid Antigen Tests for Identifying Carriers of Viable SARS-CoV-2

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2012
Author(s):  
Elena Shidlovskaya ◽  
Nadezhda Kuznetsova ◽  
Elizaveta Divisenko ◽  
Maria Nikiforova ◽  
Andrei Siniavin ◽  
...  
Keyword(s):  
Cell Culture ◽  
High Sensitivity ◽  
Diagnostic Value ◽  
Healthy People ◽  
Rt Pcr ◽  
Rapid Tests ◽  
Antigen Tests

The search for effective methods to detect patients who excrete a viable virus is one of the urgent tasks of modern biomedicine. In the present study, we examined the diagnostic value of two antigen tests, BIOCREDIT COVID-19 Ag (RapiGEN Inc., Anyang, Korea) and SGTI-flex COVID-19 Ag (Sugentech Inc., Cheongju, Korea), for their diagnostic value in identifying patients who excrete viable SARS-CoV-2. As part of the study, we examined samples from 106 patients who had just been admitted to the hospital and who had undergone quantitative RT-PCR and assessment of viability of SARS-CoV-2 using cell culture. Assessment of the tests’ value for detecting samples containing viable virus showed high sensitivity for both tests. Sensitivity was 78.6% (95% CI, from 49.2% to 95.3%) for SGTI-flex COVID-19 Ag and 100% (95% CI, from 76.8% to 100%) for Biocredit COVID-19 Ag. The specificity of rapid tests was significantly higher than that of RT-PCR and was 66.3% (95% CI, from 55.7% to 75.8%) and 67.4% (95% CI, from 56.8% to 76.8%) for SGTI-flex COVID-19 Ag and Biocredit COVID-19 Ag versus 30.4% (95% CI, from 21.3% to 40.9%) obtained for PCR. Thus, for tasks of identifying viable SARS-CoV-2 during screening of conditionally healthy people, as well as monitoring those quarantined, rapid tests show significantly better results.

scholarly journals Diagnostic accuracy of two commercial SARS-CoV-2 Antigen-detecting rapid tests at the point of care in community-based testing centers

2020 ◽  
Author(s):  
Alice Berger ◽  
Marie Therese Ngo Nsoga ◽  
Francisco Javier Perez-Rodriguez ◽  
Yasmine Abi Aad ◽  
Pascale Sattonnet-Roche ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
Point Of Care ◽  
Rapid Test ◽  
Diagnostic Value ◽  
Rapid Diagnostic Tests ◽  
Ease Of Use ◽  
Rt Pcr ◽  
Test Device ◽  
Community Based ◽  
Rapid Tests

AbstractBackgroundAntigen-detecting rapid diagnostic tests for SARS-CoV-2 offer new opportunities for the quick and laboratory-independent identification of infected individuals for control of the SARS-CoV-2 pandemic.MethodsWe performed a prospective, single-center, point of care validation of two antigen-detecting rapid diagnostic tests (Ag-RDT) in comparison to RT-PCR on nasopharyngeal swabs.FindingsBetween October 9th and 23rd, 2020, 1064 participants were enrolled. The Panbio™Covid-19 Ag Rapid Test device (Abbott) was validated in 535 participants, with 106 positive Ag-RDT results out of 124 positive RT-PCR individuals, yielding a sensitivity of 85.5% (95% CI: 78.0–91.2). Specificity was 100.0% (95% CI: 99.1–100) in 411 RT-PCR negative individuals. The Standard Q Ag-RDT (SD Biosensor, Roche) was validated in 529 participants, with 170 positive Ag-RDT results out of 191 positive RT-PCR individuals, yielding a sensitivity of 89.0% (95%CI: 83.7–93.1). One false positive result was obtained in 338 RT-PCR negative individuals, yielding a specificity of 99.7% (95%CI: 98.4–100). For individuals presenting with fever 1-5 days post symptom onset, combined Ag-RDT sensitivity was above 95%.InterpretationWe provide an independent validation of two widely available commercial Ag-RDTs, both meeting WHO criteria of ≥80% sensitivity and ≥97% specificity. Although less sensitive than RT-PCR, these assays could be beneficial due to their rapid results, ease of use, and independence from existing laboratory structures. Testing criteria focusing on patients with typical symptoms in their early symptomatic period onset could further increase diagnostic value.FundingFoundation of Innovative Diagnostics (FIND), Fondation privée des HUG, Pictet Charitable Foundation.

scholarly journals Diagnostic accuracy of two commercial SARS-CoV-2 antigen-detecting rapid tests at the point of care in community-based testing centers

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248921
Author(s):  
Alice Berger ◽  
Marie Therese Ngo Nsoga ◽  
Francisco Javier Perez-Rodriguez ◽  
Yasmine Abi Aad ◽  
Pascale Sattonnet-Roche ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Point Of Care ◽  
Rapid Test ◽  
Diagnostic Value ◽  
Ease Of Use ◽  
Lower Sensitivity ◽  
Rt Pcr ◽  
Test Device ◽  
Community Based ◽  
Rapid Tests

Objectives Determine the diagnostic accuracy of two antigen-detecting rapid diagnostic tests (Ag-RDT) for SARS-CoV-2 at the point of care and define individuals’ characteristics providing best performance. Methods We performed a prospective, single-center, point of care validation of two Ag-RDT in comparison to RT-PCR on nasopharyngeal swabs. Results Between October 9th and 23rd, 2020, 1064 participants were enrolled. The PanbioTM Covid-19 Ag Rapid Test device (Abbott) was validated in 535 participants, with 106 positive Ag-RDT results out of 124 positive RT-PCR individuals, yielding a sensitivity of 85.5% (95% CI: 78.0–91.2). Specificity was 100.0% (95% CI: 99.1–100) in 411 RT-PCR negative individuals. The Standard Q Ag-RDT (SD Biosensor, Roche) was validated in 529 participants, with 170 positive Ag-RDT results out of 191 positive RT-PCR individuals, yielding a sensitivity of 89.0% (95%CI: 83.7–93.1). One false positive result was obtained in 338 RT-PCR negative individuals, yielding a specificity of 99.7% (95%CI: 98.4–100). For individuals presenting with fever 1–5 days post symptom onset, combined Ag-RDT sensitivity was above 95%. Lower sensitivity of 88.2% was seen on the same day of symptom development (day 0). Conclusions We provide an independent validation of two widely available commercial Ag-RDTs, both meeting WHO criteria of ≥80% sensitivity and ≥97% specificity. Although less sensitive than RT-PCR, these assays could be beneficial due to their rapid results, ease of use, and independence from existing laboratory structures. Testing criteria focusing on patients with typical symptoms in their early symptomatic period onset could further increase diagnostic value.

scholarly journals Fast Detection of SARS-CoV-2 RNA Directly from Respiratory Samples Using a Loop-Mediated Isothermal Amplification (LAMP) Test

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 801
Author(s):  
Olympia E. Anastasiou ◽  
Caroline Holtkamp ◽  
Miriam Schäfer ◽  
Frieda Schön ◽  
Anna Maria Eis-Hübinger ◽  
...  
Keyword(s):  
Predictive Value ◽  
Lamp Assay ◽  
Detection Methods ◽  
Analytical Sensitivity ◽  
Rt Pcr ◽  
Viral Transport Medium ◽  
Rapid Tests ◽  
Sous Vide ◽  
Antigen Tests ◽  
Isothermal Assay

The availability of simple SARS-CoV-2 detection methods is crucial to contain the COVID-19 pandemic. This study examined whether a commercial LAMP assay can reliably detect SARS-CoV-2 genomes directly in respiratory samples without having to extract nucleic acids (NA) beforehand. Nasopharyngeal swabs (NPS, n = 220) were tested by real-time reverse transcription (RT)-PCR and with the LAMP assay. For RT-PCR, NA were investigated. For LAMP, NA from 26 NPS in viral transport medium (VTM) were tested. The other 194 NPS were analyzed directly without prior NA extraction (140 samples in VTM; 54 dry swab samples stirred in phosphate buffered saline). Ten NPS were tested directly by LAMP using a sous-vide cooking unit. The isothermal assay demonstrated excellent specificity (100%) but moderate sensitivity (68.8%), with a positive predictive value of 1 and a negative predictive value of 0.65 for direct testing of NPS in VTM. The use of dry swabs, even without NA extraction, improved the analytical sensitivity; up to 6% of samples showed signs of inhibition. LAMP could be performed successfully with a sous-vide cooking unit. This technique is very fast, requires little laboratory resources, and can replace rapid antigen tests or verify reactive rapid tests on-site.

Detection of enteroviruses in marine waters by direct RT-PCR and cell culture

1995 ◽  
Vol 31 (5-6) ◽  
pp. 323-328 ◽  
Author(s):  
K. A. Reynolds ◽  
C. P. Gerba ◽  
I. L. Pepper
Keyword(s):  
Cell Culture ◽  
Polymerase Chain Reaction Amplification ◽  
Cost Effective ◽  
The United States ◽  
Water Runoff ◽  
Rt Pcr ◽  
Marine Waters ◽  
Storm Water Runoff ◽  
Routine Monitoring ◽  
Reaction Amplification

Sewage outfalls and storm water runoff introduces pathogenic human enteric viruses into marine coastal waters, which may pose a potential public health risk. Although members of the enterovirus group have been suggested as possible indicators of sewage pollution in marine waters, the lack of rapid, sensitive and cost effective methods have prevented routine monitoring in the United States. This study compared traditional cell culture and direct RT-PCR (reverse transcriptase-polymerase chain reaction) amplification for detection of an enterovirus. Poliovirus could be recovered from 100 L of artificial seawater with an average efficiency of 77%, using adsorption and elution from electronegative filters. Viruses were eluted from the filters with 1.5% beef extract for viruses (BEV) adjusted to pH 9.5 and reconcentrated by organic flocculation to a volume of 30 mL. Substances which interfered with detection by RT-PCR were removed by treatment of the concentrates with sephadex and chelex resins. Direct RT-PCR could detect 2.5 and 0.025 PFU (plaque forming units) for single (25 cycles) and double PCR (2 × 25 cycles) in 10 μL of pure culture poliovirus samples, respectively. These methods are currently being applied to assess the occurrence of enteroviruses at marine bathing beaches influenced by sewage discharges.

scholarly journals Regulation of angiopoietin-like protein 4/fasting-induced adipose factor (Angptl4/FIAF) expression in mouse white adipose tissue and 3T3-L1 adipocytes

2008 ◽  
Vol 100 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Sarah Dutton ◽  
Paul Trayhurn
Keyword(s):  
Skeletal Muscle ◽  
Cell Culture ◽  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Culture Medium ◽  
Mrna Level ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Before And After ◽  
Stimulation Of

Angiopoietin-like protein 4 (Angptl4)/FIAF (fasting-induced adipose factor) was first identified as a target for PPAR and to be strongly induced in white adipose tissue (WAT) by fasting. Here we have examined the regulation of the expression and release of this adipokine in mouse WAT and in 3T3-L1 adipocytes. Angptl4/FIAF expression was measured by RT-PCR and real-time PCR; plasma Angptl4/FIAF and release of the protein in cell culture was determined by western blotting. The Angptl4/FIAF gene was expressed in each of the major WAT depots of mice, the mRNA level in WAT being similar to the liver and much higher (>50-fold) than skeletal muscle. Fasting mice (18 h) resulted in a substantial increase in Angptl4/FIAF mRNA in liver and muscle (9·5- and 21-fold, respectively); however, there was no effect of fasting on Angptl4/FIAF mRNA in WAT and the plasma level of Angptl4/FIAF was unchanged. The Angptl4/FIAF gene was expressed in 3T3-L1 adipocytes before and after differentiation, the level increasing post-differentiation; Angptl4/FIAF was released into the culture medium. Insulin, leptin, dexamethasone, noradrenaline, TNFα and several IL (IL-1β, IL-6, IL-10, IL-18) had little effect on Angptl4/FIAF mRNA levels in 3T3-L1 adipocytes. However, a major stimulation of Angptl4/FIAF expression was observed with rosiglitazone and the inflammatory prostaglandins PGD2 and PGJ2. Angptl4/FIAF does not act as an adipose tissue signal of nutritional status, but is markedly induced by fasting in liver and skeletal muscle.

scholarly journals HLF is a Potential Prognostic Biomarker in Head and Neck Squamous Cell Carcinoma Based on Bioinformatic Analysis and Experimental Validation

2021 ◽  
Author(s):  
Wei Fang ◽  
Di Wan ◽  
Jun Chen ◽  
Weiqun Ma ◽  
Zhen Luo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Culture ◽  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Poor Prognosis ◽  
Prognostic Biomarker ◽  
Neck Squamous Cell Carcinoma ◽  
Rt Pcr ◽  
The Relationship

Abstract BackgroundHead and neck squamous cell carcinoma (HNSCC) is one of the most frequent cancers worldwide, with an increasing incidence. However, the underlying molecular mechanisms of HNSCC are poorly understood.MethodIn this work, 5 original datasets (GSE23558, GSE13601, GSE30784, GSE9844, GSE78060) of Head and neck squamous cell carcinoma (HNSCC) were selected from Gene Expression Omnibus (GEO) database. To identify differentially expressed genes (DEGs) in HNSCC and adjacent tissues. The common DEGs were acquired by Venn diagram. The sensitivity and specificity of HLF were determined by Receiver operating characteristic curves (ROC). Then, In order to further confirm the relationship between HLF and HNSCC patient’s prognosis, the expression and survival analysis of HLF was performed by Gene Expression Profiling Interactive Analysis (GEPIA), Cell culture, reverse transcription polymerase chain reaction (RT-PCR), western blotting and immunohistochemical staining.ResultsSeventeen DEGs were screened from five sets of HNSCC functional gene expression series in GEO datasets. The low expression of HLF was indicated might be correlated with poor prognosis of HNSCC patients based on the bioinformatics analysis. According to the results of Cell culture, RT-PCR, western blotting, immunohistochemical staining, it was confirmed that the low level of HLF expression correlated with poor prognosis of HNSCC patients.ConclusionThe study effectively revealed useful information about the relationship of the low level of HLF expression and HNSCC. In summary, we identified HLF as a potential prognostic biomarker and therapeutic target for HNSCC.

scholarly journals Evaluation of the performance of the COVID-19 rapid antigen tests in a tertiary level hospital in Bangladesh.

2021 ◽  
Author(s):  
Mohammad Jahidur Rahman Khan ◽  
Md. Shahadat Hossain ◽  
Samshad Jahan Shumu ◽  
Md. Selim Reza ◽  
Farzana Mim ◽  
...  
Keyword(s):  
Viral Load ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Detection Rate ◽  
High Sensitivity ◽  
Rt Pcr ◽  
College Hospital ◽  
Medical College ◽  
Qrt Pcr ◽  
Antigen Tests

Abstract Background: While the COVID-19 pandemic is a worldwide crisis, tests with high sensitivity and specificity are essential for identifying and managing COVID-19 patients. Globally, several rapid antigen tests RATs for COVID-19 have been developed, but their clinical efficacy has not been well established. This study aimed to evaluate the performance of several rapid antigen tests (RATs) to diagnose SARS-CoV-2 infection.Methods: This prospective observational study was conducted at Shaheed Suhrawardy Medical College hospital from February 2021 to April 2021 in Dhaka, Bangladesh. This study included the patients admitted in this hospital at the COVID-19 isolation unit or referred from the triage facility of the outdoor department of this hospital suspected as COVID-19 case. Two nasopharyngeal samples were collected simultaneously. one sample was used on the spot for the RAT. The other was sent to the adjacent Shaheed Suhrawardy Medical College COVID-19 RT-PCR laboratory for real-time reverse transcription-polymerase chain reaction (qRT-PCR). The performance of the RAT was evaluated using the results of qRT-PCR as a reference.Results: A total of 223 patients were included in this study, and the real-time RT-PCR detected SARS-CoV-2 in 84 (37.7%) patients. Of these 84 patients, 9 (10.7%) were asymptomatic. The overall sensitivity and specificity of RATs were 78.6% and 99.3%, respectively. The sensitivity was 81.3% in symptomatic cases and 55.6% in asymptomatic cases. False-negatives were observed in 18 patients, 3 of whom were asymptomatic and had a low viral load (cycle threshold (Ct) > 30). The detection rate of RATs was 100% when the Ct value was up to 24. The detection rate was 42.3% when the Ct was >29. The detection rate of RATs was 92.3% when the onset of symptoms was within three days. The detection rate was 33.3% when the onset of symptoms was >7 days.Conclusions: RATs for COVID-19 used in this study delivered an acceptable performance in patients with high viral load and within the first week of the onset of symptoms. They can be used as a supplementary method to RT-PCR for the diagnosis of COVID-19 patients.

scholarly journals The Detection of Enteroviruses in Sewage Using Caco-2 Cells

2013 ◽  
Vol 62 (1) ◽  
pp. 97-100 ◽  
Author(s):  
MAGDALENA WIECZOREK ◽  
ŁUKASZ KURYK ◽  
AGNIESZKA WITEK ◽  
ANNA DIUWE ◽  
BOGUMIŁA LITWIŃSKA
Keyword(s):  
Cell Culture ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Beef Extract

The work presented here demonstrates the utility of Caco-2 cells to detect enteroviruses in sewage. Viruses were concentrated by beef extract elution and organic flocculation prior to analysis by cell culture assays and RT-PCR. Enteroviruses were detected in all sewage samples, but only one sample was positive solely in RT-PCR assay. We proved that Caco-2 cells were more effective than RD and L20B cells in enterovirus isolation, depending on procedures used in the inoculation process.

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