scholarly journals Head-to-Head Comparison of Rapid and Automated Antigen Detection Tests for the Diagnosis of SARS-CoV-2 Infection

2021 ◽  
Vol 10 (2) ◽  
pp. 265
Author(s):  
Julien Favresse ◽  
Constant Gillot ◽  
Maxime Oliveira ◽  
Julie Cadrobbi ◽  
Marc Elsen ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Clinical Performance ◽  
Antigen Detection ◽  
Clinical Validation ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Viral Loads ◽  
Automated Assay ◽  
Polymerase Chain ◽  
Asymptomatic Subjects

(1) Background: The detection of SARS-CoV-2 RNA in nasopharyngeal samples through real-time reverse transcription-polymerase chain reaction (RT-PCR) is considered the standard gold method for the diagnosis of SARS-CoV-2 infection. Antigen detection (AD) tests are more rapid, less laborious, and less expensive alternatives but still require clinical validation. (2) Methods: This study compared the clinical performance of five AD tests, including four rapid AD (RAD) tests (biotical, Panbio, Healgen, and Roche) and one automated AD test (VITROS). For that purpose, 118 (62.8%) symptomatic patients and 70 (37.2%) asymptomatic subjects were tested, and results were compared to RT-PCR. (3) Results: The performance of the RAD tests was modest and allowed us to identify RT-PCR positive patients with higher viral loads. For Ct values ≤25, the sensitivity ranged from 93.1% (95% CI: 83.3–98.1%) to 96.6% (95% CI: 88.1–99.6%), meaning that some samples with high viral loads were missed. Considering the Ct value proposed by the CDC for contagiousness (i.e., Ct values ≤33) sensitivities ranged from 76.2% (95% CI: 65.4–85.1%) to 88.8% (95% CI: 79.7–94.7%) while the specificity ranged from 96.3% (95% CI: 90.8–99.0%) to 99.1% (95% CI: 95.0–100%). The VITROS automated assay showed a 100% (95% CI: 95.5–100%) sensitivity for Ct values ≤33, and had a specificity of 100% (95% CI: 96.6–100%); (4) Conclusions: Compared to RAD tests, the VITROS assay fully aligned with RT-PCR for Ct values up to 33, which might allow a faster, easier and cheaper identification of SARS-CoV-2 contagious patients.

scholarly journals EXPRESS: Clinical performance of the Elecsys® Anti-SARS-CoV-2 combined in an algorithm with two specific anti-IgG immunoassays for the evaluation of the serological response of patients with COVID-19 in a population with a high prevalence of infection

2021 ◽  
pp. 000456322110380
Author(s):  
Xavier Gabaldó-Barrios ◽  
Simona Iftimie ◽  
Anna Hernández-Aguilera ◽  
Isabel Pujol ◽  
Frederic Ballester ◽  
...  
Keyword(s):  
Immune Response ◽  
Polymerase Chain Reaction ◽  
Predictive Value ◽  
Clinical Performance ◽  
Polymerase Chain Reaction Test ◽  
Serological Response ◽  
Chain Reaction ◽  
Automated Assay ◽  
High Prevalence ◽  
Polymerase Chain

Background: Anti-SARS-CoV-2 antibodies have been used in the study of the immune response in infected patients. However, differences in sensitivity and specificity have been reported, depending on the method of analysis. The aim of the present study was to evaluate the diagnostic accuracy of an algorithm in which a high-throughput automated assay for total antibodies was used for screening and two semi-automated IgG-specific methods were used to confirm the results, and also to correlate the analytical results with the clinical data and the time elapsed since infection. Methods: We studied 306 patients, some hospitalized and some outpatients, belonging to a population with a high prevalence of COVID-19. One-hundred and ten patients were classified as SARS-CoV-2 negative and 196 as positive by polymerase chain reaction. Results: The algorithm and automated assay alone had a specificity and a positive predictive value of 100%, although the sensitivity and negative predictive value of the algorithm was higher. Both methods showed a good sensitivity from day 11 of the onset of symptoms in asymptomatic and symptomatic patients. The absorbance of the total antibodies was significantly higher in severely symptomatic than in asymptomatic or mildly symptomatic patients, which suggests the antibody level was higher. We found 15 patients that did not present seroconversion at 12 days from the onset of symptoms or the first polymerase chain reaction test. Conclusion: This study highlights the proper functioning of algorithms in the diagnosis of the immune response to COVID-19, which can help to define testing strategies against this disease.

scholarly journals Comparison of nonstructural protein-1 antigen detection by rapid and enzyme-linked immunosorbent assay test and its correlation with polymerase chain reaction for early diagnosis of dengue

2017 ◽  
Vol 9 (03) ◽  
pp. 177-181 ◽  
Author(s):  
Seema Gaikwad ◽  
Sandhya S. Sawant ◽  
Jayanthi S. Shastri
Keyword(s):  
Polymerase Chain Reaction ◽  
Nonstructural Protein ◽  
Antigen Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Nonstructural Protein 1 ◽  
Ns1 Antigen ◽  
Polymerase Chain ◽  
Sera Samples

Abstract INTRODUCTION: Early diagnosis of dengue is important for appropriate clinical management and vector control. Different serological tests based on the principle of immunochromatography and enzyme-linked immunosorbent assay (ELISA) are commonly used for detection of antigen and antibodies of dengue virus. The performance of these tests depends on the sensitivity and specificity. Hence, the study was undertaken to compare nonstructural protein-1 (NS1) antigen detection by rapid and ELISA with real-time polymerase chain reaction (RT-PCR) for diagnosis of dengue. MATERIALS AND METHODS: Prospective laboratory study was carried out on sera samples (n = 200) from clinically suspected cases of dengue. The sera samples were subjected for NS1 antigen detection test by rapid test, NS1 ELISA, and RT-PCR. The results of rapid and ELISA tests were compared with real Time PCR. RESULTS: The sensitivity, specificity, positive, and negative predictive value of rapid dengue NS1 antigen test were 81.5%, 66.7%, 78.2%, and 71.1%, respectively whereas that of NS1 ELISA were 89.9%, 100%, 100%, and 94%, respectively. Concordance of Rapid NS1 and NS1 ELISA with PCR was 75.5% and 94%. DISCUSSION AND CONCLUSION: NS1 antigen ELISA can be implemented in diagnostic laboratories for diagnosis of dengue in the acute phase of illness. The test also has great potential value for use in epidemic situations, as it could facilitate the early screening of patients and limit disease expansion.

scholarly journals Comparison of SARS-CoV-2 viral load in saliva samples in symptomatic and asymptomatic cases

2021 ◽  
Author(s):  
Anuja Bhatta ◽  
Rebecca Henkhaus ◽  
Heather L. Fehling
Keyword(s):  
Polymerase Chain Reaction ◽  
Viral Load ◽  
Reverse Transcription ◽  
Specific Gene ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Gene Target ◽  
Viral Loads ◽  
Ct Value ◽  
Polymerase Chain

AbstractSARS-CoV-2 infections can be symptomatic as well as asymptomatic. In this study, we analyzed 460,814 saliva samples collected from July 2020 to January 2021 for a SARS-CoV-2-specific gene target using the FDA EUA test, CRL Rapid Response™, based on reverse transcription polymerase chain reaction (RT-PCR). We measured SARS-CoV-2 viral loads using cycle threshold (Ct) values. A total of 17,813 samples tested positive for COVID-19 using self-collected saliva samples. The Ct values ranged from 11 to 40, 91.3% distributed between 22 to 38 Ct. We then compared Ct values for symptomatic and asymptomatic cases for all positive saliva samples. A total of 8,706 cases were symptomatic with an average Ct value of 29.24, and 9,107 cases were asymptomatic with an average Ct value of 30.99. Hence, SARS-CoV-2 viral loads (Ct) in saliva samples for both symptomatic and asymptomatic cases are similar.

1504: Molecular Diagnosis and Staging of Prostate Cancer Using Clusterin in Real Time Reverse Transcription Polymerase Chain Reaction (RT-PCR)

2006 ◽  
Vol 175 (4S) ◽  
pp. 485-486
Author(s):  
Sabarinath B. Nair ◽  
Christodoulos Pipinikas ◽  
Roger Kirby ◽  
Nick Carter ◽  
Christiane Fenske
Keyword(s):  
Prostate Cancer ◽  
Polymerase Chain Reaction ◽  
Real Time ◽  
Molecular Diagnosis ◽  
Reverse Transcription ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain

Polymerase chain reaction amplification and typing of rotavirus in environmental samples

1995 ◽  
Vol 31 (5-6) ◽  
pp. 371-374 ◽  
Author(s):  
R. Gajardo ◽  
R. M. Pintó ◽  
A. Bosch
Keyword(s):  
Polymerase Chain Reaction ◽  
Environmental Samples ◽  
Polymerase Chain Reaction Amplification ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Group A ◽  
Reaction Amplification ◽  
Stool Specimens ◽  
Polymerase Chain

A reverse transcription polymerase chain reaction (RT-PCR) assay is described that has been developed for the detection and serotyping of group A rotavirus in stool specimens and concentrated and non-concentrated sewage specimens.

scholarly journals Machine Learning Prediction of SARS-CoV-2 Polymerase Chain Reaction Results with Routine Blood Tests

2020 ◽  
Author(s):  
Thomas Tschoellitsch ◽  
Martin Dünser ◽  
Carl Böck ◽  
Karin Schwarzbauer ◽  
Jens Meier
Keyword(s):  
Machine Learning ◽  
Polymerase Chain Reaction ◽  
Characteristic Curve ◽  
Cohort Analysis ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Blood Tests ◽  
Routine Blood ◽  
Machine Learning Model ◽  
Polymerase Chain

Abstract Objective The diagnosis of COVID-19 is based on the detection of SARS-CoV-2 in respiratory secretions, blood, or stool. Currently, reverse transcription polymerase chain reaction (RT-PCR) is the most commonly used method to test for SARS-CoV-2. Methods In this retrospective cohort analysis, we evaluated whether machine learning could exclude SARS-CoV-2 infection using routinely available laboratory values. A Random Forests algorithm with 1353 unique features was trained to predict the RT-PCR results. Results Out of 12,848 patients undergoing SARS-CoV-2 testing, routine blood tests were simultaneously performed in 1528 patients. The machine learning model could predict SARS-CoV-2 test results with an accuracy of 86% and an area under the receiver operating characteristic curve of 0.90. Conclusion Machine learning methods can reliably predict a negative SARS-CoV-2 RT-PCR test result using standard blood tests.

scholarly journals A meta-analysis of accuracy and sensitivity of chest CT and RT-PCR in COVID-19 diagnosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fatemeh Khatami ◽  
Mohammad Saatchi ◽  
Seyed Saeed Tamehri Zadeh ◽  
Zahra Sadat Aghamir ◽  
Alireza Namazi Shabestari ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcriptase ◽  
Ct Scan ◽  
Predictive Value ◽  
Meta Analysis ◽  
Chest Ct ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Chest Ct Scan

AbstractNowadays there is an ongoing acute respiratory outbreak caused by the novel highly contagious coronavirus (COVID-19). The diagnostic protocol is based on quantitative reverse-transcription polymerase chain reaction (RT-PCR) and chests CT scan, with uncertain accuracy. This meta-analysis study determines the diagnostic value of an initial chest CT scan in patients with COVID-19 infection in comparison with RT-PCR. Three main databases; PubMed (MEDLINE), Scopus, and EMBASE were systematically searched for all published literature from January 1st, 2019, to the 21st May 2020 with the keywords "COVID19 virus", "2019 novel coronavirus", "Wuhan coronavirus", "2019-nCoV", "X-Ray Computed Tomography", "Polymerase Chain Reaction", "Reverse Transcriptase PCR", and "PCR Reverse Transcriptase". All relevant case-series, cross-sectional, and cohort studies were selected. Data extraction and analysis were performed using STATA v.14.0SE (College Station, TX, USA) and RevMan 5. Among 1022 articles, 60 studies were eligible for totalizing 5744 patients. The overall sensitivity, specificity, positive predictive value, and negative predictive value of chest CT scan compared to RT-PCR were 87% (95% CI 85–90%), 46% (95% CI 29–63%), 69% (95% CI 56–72%), and 89% (95% CI 82–96%), respectively. It is important to rely on the repeated RT-PCR three times to give 99% accuracy, especially in negative samples. Regarding the overall diagnostic sensitivity of 87% for chest CT, the RT-PCR testing is essential and should be repeated to escape misdiagnosis.

scholarly journals Evaluation of Sandwich Enzyme-Linked Immunosorbent Assay and Reverse Transcription Polymerase Chain Reaction for the Diagnosis of Foot-and-Mouth Disease

Intervirology ◽  
2021 ◽  
pp. 1-6
Author(s):  
Salman Khan ◽  
Syed Asad Ali Shah ◽  
Syed Muhammad Jamal
Keyword(s):  
Polymerase Chain Reaction ◽  
Viral Genome ◽  
Foot And Mouth Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Kappa Value ◽  
Polymerase Chain ◽  
Pcr Assays ◽  
Level Of Agreement

<b><i>Background:</i></b> Foot-and-mouth disease (FMD) is an infectious and highly contagious disease of cloven-hoofed domestic and wild animals, causing heavy economic losses to the livestock industry. Rapid and reliable diagnosis of the disease is essential for the implementation of effective control measures. This study compared sandwich enzyme-linked immunosorbent assay (S-ELISA) and conventional reverse transcription polymerase chain reaction (RT-PCR) for the diagnosis of FMD. <b><i>Methods:</i></b> A total of 60 epithelial samples from suspected cases of FMD were tested using both S-ELISA and RT-PCR assays. The level of agreement between the assays was assessed by calculating the Kappa value. <b><i>Results:</i></b> S-ELISA detected 38 (63%) samples positive for FMD virus (FMDV). Being predominant, serotype O was detected in 22 (57.9%) of the total samples tested positive, whereas 9 (23.7%) and 7 (18.4%) samples were found positive for serotypes A and Asia-1, respectively. RT-PCR detected viral genome in 51 (85%) of the samples using pan-FMDV primers set, 1F/1R. Thirty-six samples were found positive and 7 negative by both the tests. The level of agreement between the tests was assessed by calculating the Kappa value, which was found to be fair (Kappa value = 0.303 and 95% CI = 0.089; 0.517) and significant (<i>p</i> = 0.009). However, 2 samples, which were found positive on S-ELISA tested negative on RT-PCR. This may be attributed to the presence of nucleotide mismatch(es) in the primer-binding sites that may have resulted in failure of amplification of the viral genome. The serotype-specific RT-PCR assays not only confirmed serotyping results of S-ELISA but were also able to establish serotype in 9 S-ELISA-negative but pan-FMDV RT-PCR-positive samples. <b><i>Conclusions:</i></b> The RT-PCR assay contributes significantly to establishing a quick, sensitive, and definitive diagnosis of FMD in resource-constrained countries. Samples giving negative results in S-ELISA should be tested in RT-PCR for the disease detection and virus typing.

Detection of specific mRNAs in single nephron segments by use of the polymerase chain reaction

1990 ◽  
Vol 258 (5) ◽  
pp. F1470-F1474 ◽  
Author(s):  
T. Moriyama ◽  
H. R. Murphy ◽  
B. M. Martin ◽  
A. Garcia-Perez
Keyword(s):  
Polymerase Chain Reaction ◽  
Aldose Reductase ◽  
Collecting Duct ◽  
Specific Gene ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Nephron Segments ◽  
Single Nephron ◽  
Specific Mrnas ◽  
Polymerase Chain

We have developed a procedure to detect specific mRNAs in single renal nephron segments. This approach combines microdissection, reverse transcription (RT) of the target mRNA, and amplification of the resulting cDNA using the polymerase chain reaction (PCR). After microdissection, the sample is placed in a tube where it is permeabilized and where all reactions are performed directly without the need for isolation of the RNA. Our model target was the mRNA for aldose reductase. This enzyme catalyzes the conversion of glucose to sorbitol. Its expression is modulated by changes in extracellular osmolality in the renal medulla. RT-PCR of inner medullary collecting duct (1 mm) and glomeruli (6-10) yielded a product of the predicted length (670 base pairs) defined by the PCR primers. Its identity was confirmed by a specific oligonucleotide probe that differed from the primers. RT-PCR of proximal tubules (1 mm) resulted in no aldose reductase-specific amplification product. RT-PCR is generally applicable for measuring specific gene expression in single nephron segments or small numbers of cultured cells. Utility, limitations, and refinements of this approach are discussed.

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