scholarly journals Performance of the LIAISON® SARS-CoV-2 Antigen Assay vs. SARS-CoV-2-RT-PCR

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 658
Author(s):  
Melanie Fiedler ◽  
Caroline Holtkamp ◽  
Ulf Dittmer ◽  
Olympia E. Anastasiou
Keyword(s):  
Reference Method ◽  
Respiratory Viruses ◽  
Cross Reactivity ◽  
Clinical Samples ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Viral Loads ◽  
Antigen Assay ◽  
Polymerase Chain

We aimed to evaluate the LIAISON® SARS-CoV-2 antigen assay (DiaSorin), comparing its performance to real-time polymerase chain reaction (RT-PCR) for the detection of SARS-CoV-2 RNA. 182 (110 PCR-positive and 72 PCR-negative) nasopharyngeal swab samples were taken for the detection of SARS-CoV-2. RT-PCR and antigen assay were performed using the same material. The sensitivity and specificity of the antigen assay were calculated for different cut-offs, with RT-PCR serving as the reference method. Stored clinical samples that were positive for other respiratory viruses were tested to evaluate cross-reactivity. One third (33/110, 30%) were falsely classified as negative, while no false positives were found using the 200 TCID50/mL cut-off for the SARS-CoV-2 antigen as proposed by the manufacturer. This corresponded to a sensitivity of 70% (60–78%) and a specificity of 100% (94–100%). Lowering the cut-off for positivity of the antigen assay to 22.79 or 57.68 TCID50/mL increased the sensitivity of the method, reaching a sensitivity of 92% (85–96%) vs. 79% (70–86%) and a specificity of 81% (69–89%) vs. 99% (91–100%), respectively. The antigen assay reliably detected samples with high SARS-CoV-2 viral loads (≥106 copies SARS-CoV-2/mL), while it cannot differentiate between negative and low positive samples. Cross-reactivity toward other respiratory viruses was not detected.

scholarly journals Evaluation of two fluorescence immunoassays for the rapid detection of SARS-CoV-2 antigen—new tool to detect infective COVID-19 patients

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10801
Author(s):  
Lorena Porte ◽  
Paulette Legarraga ◽  
Mirentxu Iruretagoyena ◽  
Valeska Vollrath ◽  
Gabriel Pizarro ◽  
...  
Keyword(s):  
Rapid Detection ◽  
High Performance ◽  
Diagnostic Method ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Viral Loads ◽  
The World ◽  
Polymerase Chain ◽  
Potential Use

Background Real-Time Reverse-Transcription Polymerase Chain Reaction (RT-PCR) is currently the only recommended diagnostic method for SARS-CoV-2. However, rapid immunoassays for SARS-CoV-2 antigen could significantly reduce the COVID-19 burden currently weighing on laboratories around the world. Methods We evaluated the performance of two rapid fluorescence immunoassays (FIAs), SOFIA SARS Antigen FIA (Quidel Corporation, San Diego, CA, USA) and STANDARD F COVID-19 Ag FIA (SD Biosensor Inc., Gyeonggi-do, Republic of Korea), which use an automated reader. The study used 64 RT-PCR characterized clinical samples (32 positive; 32 negative), which consisted of nasopharyngeal swabs in universal transport medium. Results Of the 32 positive specimens, all from patients within 5 days of symptom onset, the Quidel and SD Biosensor assays detected 30 (93.8%) and 29 (90.6%) samples, respectively. Among the 27 samples with high viral loads (Ct ≤ 25), the two tests had a sensitivity of 100%. Specificity was 96.9% for both kits. Conclusion The high performance of the evaluated FIAs indicates a potential use as rapid and PCR-independent tools for COVID-19 diagnosis in early stages of infection. The excellent sensitivity to detect cases with viral loads above ~106 copies/mL (Ct values ≤ 25), the estimated threshold of contagiousness, suggests that the assays might serve to rapidly identify infective individuals.

scholarly journals Evaluation of A Chemiluminescent Enzyme Immunoassay-Based High-Throughput SARS-CoV-2 Antigen Assay For The Diagnosis of COVID-19: The VITROS® SARS-CoV-2 Antigen Test

2021 ◽  
Author(s):  
Nanako Matsuzaki ◽  
Yuta Orihara ◽  
Masahiro Kodana ◽  
Yutaro Kitagawa ◽  
Masaru Matsuoka ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
High Throughput ◽  
Nasopharyngeal Swab ◽  
Antigen Test ◽  
Chain Reaction ◽  
Viral Loads ◽  
Antigen Assay ◽  
Polymerase Chain ◽  
Dose Dependent ◽  
Chemiluminescent Enzyme Immunoassay

Abstract A high-throughput, fully automated antigen detection test for SARS-CoV-2 is a viable alternative to reverse transcription polymerase chain reaction (RT-qPCR) for mass screening during outbreaks. In this study, we compared RT-qPCR for viral load and the VITROS® SARS-CoV-2 Antigen Test with reference to the results of the LUMIPULSE® SARS-CoV-2 Ag Test. Of 128 nasopharyngeal swab specimens taken from patients suspected of being infected with SARS-CoV-2, 49 were positive and 79 were negative according to RT-qPCR. Consistent dose-dependent detection with VITROS® assay was successfully achieved when using nasopharyngeal swab specimens with Ct values of ≤32.0, whereas the CLEIA-based the LUMIPULSE® assay was able to detect lower viral loads compared with the VITROS® assay. Our results show that the performance of the VITROS® assay was satisfactory for the diagnosis of contagious COVID-19 patients in the clinical setting.

Multiplex Nested Reverse Transcription-Polymerase Chain Reaction for Respiratory Viruses in Acute Otitis Media

2003 ◽  
Vol 112 (3) ◽  
pp. 252-257 ◽  
Author(s):  
Toshio Ishibashi ◽  
Hiroko Monobe ◽  
Masanobu Shinogami ◽  
Yuka Nomura ◽  
Jun Yano
Keyword(s):  
Polymerase Chain Reaction ◽  
Otitis Media ◽  
Reverse Transcription ◽  
Acute Otitis Media ◽  
Respiratory Viruses ◽  
Molecular Technique ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Polymerase Chain

Because respiratory viruses play an important role in the causation and pathogenesis of acute otitis media (AOM), determining which virus has infected a child is important with respect to vaccines and antiviral drugs. In some instances, this information might be used to prevent the occurrence of AOM. We used a rapid, economical, and sensitive diagnostic system involving a multiplex nested reverse transcription–polymerase chain reaction (RT-PCR) assay to detect various respiratory viruses in clinical specimens of middle ear fluid (MEF) from children with AOM in our hospital. Multiplex RT-PCR was completed on 40 MEF samples from 28 infants and children less than 6 years old with AOM. Viral RNA was detected in 17 MEF samples (43%). Respiratory syncytial virus type A was present in 12 samples, adenovirus in 3, rhinovirus in 2, and influenza A (H3N2) in 1. The multiplex RT-PCR assay is recommended to clinical laboratories that are considering adoption of a molecular technique for viral diagnosis.

scholarly journals Detection of SARS-CoV-2 by real time Reverse Transcriptase-Polymerase Chain Reaction assay in pleural effusion

2021 ◽  
pp. 201
Author(s):  
Keyword(s):  
Polymerase Chain Reaction ◽  
Pleural Effusion ◽  
Reverse Transcriptase ◽  
Pleural Fluid ◽  
Interstitial Pneumonia ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Pleural Involvement

SARS-CoV-2 (severe acute respiratory syndrome-coronavirus-2) is a novel coronavirus identified for the first time in Wuhan (China) in 2019, responsible of the current pandemic infection known as Coronavirus-19 disease (COVID-19). Wide range of clinical presentation of COVD -19 has been observed, from asymptomatic carriers to ARDS. The common signs and symptoms of SARS-CoV-2 infection include fever, fatigue, dry cough, and dyspnoea; the severity of the disease is due to the impairment of the respiratory function. The radiological findings include a large variety of lesions; bilateral interstitial pneumonia is the most concerning presentation of COVID-19. Pleural involvement has been described in a minority of cases: pleural thickening had been observed in 32% of cases whereas pleural effusion is uncommon being described in only 5%. Furthermore, pleural involvement has been significantly associated with a worse prognosis. Coronavirus 2 (SARS-CoV-2), beyond the nasopharyngeal swab, has been detected in other samples; up to now, data about RT-PCR specific results in the pleural fluid of patients suffering from coronavirus disease 2019 5 (COVID-19) are very limited. The current gold standard for diagnosis is nucleic acid detection by real time Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) in nasopharyngeal swab. In this report, a case of a positive RT-PCR for Sars-Cov-2 in the pleura fluid and in the naso- pharyngeal swab of a patient affected by bilateral interstitial pneumonia and severe respiratory failure is described. As the presence of SARS-Cov-2 in the pleural fluid seems to be associated to a poor prognosis, physicians should carry out the specific RT-PCR assay both in the nasopharyngeal swab and in the pleural sample also when the fluid amount is very scarce and not recognizable in the chest X ray. Furthermore, the analysis of multiple samples allows to increase the test reliability.

scholarly journals Systematic Review and Meta-analysis of Real-time Polymerase Chain Reaction assay for the detection of COVID-19 from clinical samples in low-and middle-income countries: Protocol

2021 ◽  
Author(s):  
Emmanuel Oladipo Babafemi
Keyword(s):  
Systematic Review ◽  
Polymerase Chain Reaction ◽  
Real Time ◽  
Meta Analysis ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Middle Income ◽  
Polymerase Chain

Abstract Background: COVID-19 has spread globally since its discovery in Hubei province, China in December 2019 and became pandemic in 2020. COVID-19 is a new betacoronavirus and a variant of severe acute respiratory syndrome coronavirus 2 (SARA- CoV-2). Rapid, accurate and reliable diagnosis of COVID-19 will prevent the spread and allow for appropriate management. The main objective of this systematic review is to identify, appraise and summarise the published evidence on the diagnostic performance and effectiveness of SARS-CoV-2 virus in the diagnosis of current or previous COVID-19 using real-time polymerase chain reaction (RT-PCR) assay in low-and middle-income countries (LMICs). Methods: We will search MEDLINE/PubMed, EMBASE, BIOSIS, LILACS, Cochrane Infectious Diseases Group Specialised Register (CIDG SR), Global Health, and CINAHL for published studies for the diagnosis of COVID-19 using real-time polymerase chain reaction assay in LMICs There will be no restriction regarding the language, date of publication, and publication status. We will include retrospective, cross-sectional and cohort observational studies will be included in the review. Selection of studies, data extraction and management, assessment of risk of bias, and quality of evidence will be performed by two independent reviewers (EB and BC). A third researcher (GM) will be consulted in case of discrepancies. Depending on the availability and quality of the data, a meta-analysis will be performed. Otherwise, findings will be qualitatively reported. Discussion: To our knowledge, this is the first systematic review and meta-analysis to assess the uptake of RT-PCR assay for SARS-CoV-2 detection from clinical samples in human in LMICs. This review will make available evidence on the uptake, accuracy, approach, and interpretation of results of this assay in the context of COVID-19 diagnosis which will meet an urgent need, considering the diagnostic challenges of RT-PCR assay for COVID-19 diagnosis in humans. Systematic review registration: PROSPERO CRD42021271894

scholarly journals High Resolution CHEST CT(HRCT) Evaluation in Patients Hospitalized with COVID-19 Infection

2020 ◽  
Author(s):  
Maulin Patel ◽  
Junad Chowdhury ◽  
Matthew Zheng ◽  
Osheen Abramian ◽  
Steven Verga ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
High Resolution ◽  
Diagnostic Accuracy ◽  
Reverse Transcriptase ◽  
Retrospective Analysis ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Bottom Line ◽  
Polymerase Chain

AbstractIntroductionCurrently the main diagnostic modality for COVID-19 (Coronavirus disease-2019) is reverse transcriptase polymerase chain reaction (RT-PCR) via nasopharyngeal swab which has high false negative rates. We evaluated the performance of high-resolution computed tomography (HRCT) imaging in the diagnosis of suspected COVID-19 infection compared to RT-PCR nasopharyngeal swab alone in patients hospitalized for suspected COVID-19 infection.MethodsThis was a retrospective analysis of 324 consecutive patients admitted to Temple University Hospital. All hospitalized patients who had RT-PCR testing and HRCT were included in the study. HRCTs were classified as Category 1, 2 or 3. Patients were then divided into four groups based on HRCT category and RT-PCR swab results for analysis.ResultsThe average age of patients was 59.4 (±15.2) years and 123 (38.9%) were female. Predominant ethnicity was African American 148 (46.11%). 161 patients tested positive by RT-PCR, while 41 tested positive by HRCT. 167 (52.02%) had category 1 scan, 63 (19.63%) had category 2 scan and 91 (28.35%) had category 3 HRCT scans. There was substantial agreement between our radiologists for HRCT classification (κ = 0.64). Sensitivity and specificity of HRCT classification system was 77.6 and 73.7 respectively. Ferritin, LDH, AST and ALT were higher in Group 1 and D-dimers levels was higher in Group 3; differences however were not statistically significant.ConclusionDue to its high infectivity and asymptomatic transmission, until a highly sensitive and specific COVID-19 test is developed, HRCT should be incorporated into the assessment of patients who are hospitalized with suspected COVID-19.Key PointsKey QuestionCan High Resolution CT chest (HRCT) improve diagnostic accuracy of current Nasopharyngeal swab in suspected COVID-19 patients?Bottom LineIn this retrospective analysis, our novel HRCT classification identified 20% of all COVID-19 patients who had negative nasopharyngeal reverse transcriptase polymerase chain reaction (RT-PCR) tests but had HRCT findings consistent with COVID-19 pneumonia. These patients were ruled out for other infections and laboratory markers were similar to other RT-PCR positive patientsWhy Read onOur new HRCT classification when combined with RT-PCR can improve diagnostic accuracy while promptly improving triaging in COVID-19 patients.

scholarly journals Symptoms COVID 19 Positive Vapers Compared to COVID 19 Positive Non-vapers

2022 ◽  
Vol 13 ◽  
pp. 215013192110626
Author(s):  
David D. McFadden ◽  
Shari L. Bornstein ◽  
Robert Vassallo ◽  
Bradley R. Salonen ◽  
Mohammed Nadir Bhuiyan ◽  
...  
Keyword(s):  
Nasopharyngeal Swab ◽  
Symptom Experience ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Age And Gender ◽  
Robust Variance ◽  
Polymerase Chain ◽  
And Gender ◽  
Variance Estimates ◽  
The Impact

Objectives: The purpose of the present study was to assess and describe the severity of symptoms reported by Covid-19 positive patients who vaped (smoked e-cigarettes) when compared to those who did not vape or smoke at the time of the diagnosis of Covid-19. Methods: Patients from this study are from a well-characterized patient cohort collected at Mayo Clinic between March 1, 2020 and February 28, 2021; with confirmed COVID-19 diagnosis defined as a positive result on reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assays from nasopharyngeal swab specimens. Among the 1734 eligible patients, 289 patients reported current vaping. The cohort of vapers (N = 289) was age and gender matched to 1445 covid-19 positive patients who did not vape. The data analyzed included: date of birth, gender, ethnicity, race, marital status, as well as lifestyle history such as vaping and smoking and reported covid-19 symptoms experienced. Results: A logistic regression analysis was performed separately for each symptom using generalized estimating equations (GEE) with robust variance estimates in order to account for the 1:5 age, sex, and race matched set study design. Patients who vaped and developed Covid-19 infection were more likely to have chest pain or tightness (16% vs 10%, vapers vs non vapers, P = .005), chills (25% vs 19%, vapers vs non vapers, P = .0016), myalgia (39% vs 32%, vapers vs non vapers, P = .004), headaches (49% vs 41% vapers vs non vapers, P = .026), anosmia/dysgeusia (37% vs 30%, vapers vs non vapers, P = .009), nausea/vomiting/abdominal pain (16% vs 10%, vapers vs non vapers, P = .003), diarrhea (16% vs 10%, vapers vs non vapers, P = .004), and non-severe light-headedness (16% vs 9%, vapers vs non vapers, P < .001). Conclusion: Vapers experience higher frequency of covid-19 related symptoms when compared with age and gender matched non-vapers. Further work should examine the impact vaping has on post-covid symptom experience.

scholarly journals Long-term effects of coronavirus disease 2019 on the cardiovascular system, CV COVID registry: A structured summary of a study protocol

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255263
Author(s):  
Victor Arévalos ◽  
Luis Ortega-Paz ◽  
Diego Fernandez-Rodríguez ◽  
Víctor Alfonso Jiménez-Díaz ◽  
Jordi Bañeras Rius ◽  
...  
Keyword(s):  
Primary Outcome ◽  
Cardiovascular Outcomes ◽  
Clinical Event ◽  
Nasopharyngeal Swab ◽  
Long Term Effects ◽  
Rt Pcr ◽  
Heart Failure Hospitalization ◽  
Chain Reaction ◽  
Polymerase Chain

Background Patients presenting with the coronavirus-2019 disease (COVID-19) may have a high risk of cardiovascular adverse events, including death from cardiovascular causes. The long-term cardiovascular outcomes of these patients are entirely unknown. We aim to perform a registry of patients who have undergone a diagnostic nasopharyngeal swab for SARS-CoV-2 and to determine their long-term cardiovascular outcomes. Study and design This is a multicenter, observational, retrospective registry to be conducted at 17 centers in Spain and Italy (ClinicalTrials.gov number: NCT04359927). Consecutive patients older than 18 years, who underwent a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for SARS-CoV2 in the participating institutions, will be included since March 2020, to August 2020. Patients will be classified into two groups, according to the results of the RT-PCR: COVID-19 positive or negative. The primary outcome will be cardiovascular mortality at 1 year. The secondary outcomes will be acute myocardial infarction, stroke, heart failure hospitalization, pulmonary embolism, and serious cardiac arrhythmias, at 1 year. Outcomes will be compared between the two groups. Events will be adjudicated by an independent clinical event committee. Conclusion The results of this registry will contribute to a better understanding of the long-term cardiovascular implications of the COVID19.

DETECTION OF RESPIRATORY SYNCITIAL VIRUS (RSV) IN LOWER ACUTE RESPIRATORY INFECTIONS BY NESTED REVERSE TRANSCRIPTION- POLYMERASE CHAIN REACTION

2011 ◽  
pp. 11-15
Author(s):  
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcription ◽  
Respiratory Infections ◽  
Clinical Samples ◽  
Acute Respiratory Infections ◽  
Rt Pcr ◽  
Minimal Level ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Polymerase Chain

Objective: To develop and apply a nested reverse transcription- polymerase chain reaction (nested RT-PCR) for detection of RSV in lower acute respiratory infections. Materials and methods: A nested reverse transcription- polymerase chain reaction was used to amplify a sequence of the F gene in the RSV genomic RNA, optimized and compared the sensitivity and specificity of this assay with the control samples and then applied this procedure for diagnosing RSV from clinical samples. Results: This nested RT-PCR assay amplified the specific target fragment of RSV RNA and did not amplify any sequence of genomes of the tested common viruses and bacteria causing respiratory infections. The minimal level of detection of this procedure was 102 copies/ml. Results for detection of RSV on 109 samples of throat swabs or nasopharyngeal swabs from children with lower respiratory infections showed that twenty seven patients were positive with RSV ( 24.8%), among which six out of 30 (20%) were with bronchitis, seven out of 26 ( 27%) were with bronchiolitis and fourteen out of 53 (26.4%) were with pneumonia. Conclusion: This nested RT-PCR was found to be useful and reliable for detection of RSV in respiratory infections.

scholarly journals Detection of Bluetongue Virus Serogroup by Polymerase Chain Reaction

1992 ◽  
Vol 4 (4) ◽  
pp. 400-405 ◽  
Author(s):  
Geoffrey Y. Akita ◽  
Jarasvech Chinsangaram ◽  
Bennie I. Osburn ◽  
Marius Ianconescu ◽  
Rozalia Kaufman
Keyword(s):  
Polymerase Chain Reaction ◽  
Bluetongue Virus ◽  
Wide Spectrum ◽  
Genome Segment ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Field Isolates ◽  
Viral Particles ◽  
Polymerase Chain

To facilitate detection of active bluetongue virus (BTV) infection, a polymerase chain reaction (PCR) protocol was developed. The BTV reverse transcriptase PCR (RT-PCR) is a 1-tube reaction and involves chemical denaturation of the double-stranded viral RNA target, a complementary DNA (cDNA) synthesis step, and PCR amplification of the cDNA. BTV RT-PCR using primers derived from highly conserved genome segment 10 results in a 251–base pair (bp) product. BTV RNA from all USA prototype serotypes 2, 10, 11, 13, and 17; a wide spectrum of USA BTV field isolates including serotypes 10, 11, 13, and 17; and a spectrum of Israeli field isolates including serotypes 2, 4, 6, 10, and 16 were detected by BTV RT-PCR. With agarose gels, the 251–bp product was detected from as little as 100 fg-1 pg of BTV RNA, which is equivalent to 5 × 103-5 × 104 viral particles or 5 × 102-5 × 103 infectious units. With dot blot hybridization, specific PCR product was detected from as little as 1 fg of BTV RNA, which is equivalent to 50 viral particles, or 5 infectious units. This level of sensitivity is comparable to that of virus isolation. The BTV RT-PCR using primers derived from genome segment 10 can detect a wide spectrum of USA and Israeli BTV serotypes and has potential for detection of infection by the BTV serogroup. Application of this BTV PCR to clinical samples is in progress.

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