A rapid near-patient RT-PCR test for suspected COVID-19: a study of the diagnostic accuracy (original) (raw)
Related papers
Performance of an Antigen Rapid Test Compared to RT-PCR for the Detection of SARS-CoV-2
Journal of Pharmaceutical Research International
Background: Rapid and accurate diagnosis of COVID-19 is critical for the management of patients and to limit the spread of the infection. real-time reverse transcription polymerase chain reaction (RT- PCR) is the gold standard for the diagnosis of SARS-CoV-2 infection, however, it is costly and requires time to obtain a result. A number of alternative rapid tests are available now to provide a faster and more convenient solution for the diagnosis of COVID-19. The aim of this work was to compare the performance of a SARS-Cov-2 Antigen Rapid Test (ART) Cassette to the RT-PCR conventional method. Methods: Two nasopharyngeal swabs were taken from each of the 126 patients included in this study. Of those, 23 were healthy individuals, 9 were confirmed COVID-19 patients and 103 patients from COVID-19 isolation ward in the hospital. For each patient, one sample was processed for RT-PCR and a second swab was used on the ART kit. Results: Participants were 57.5% males and 42.5% females. The a...
Utility of Available Methods for Diagnosing SARS-CoV-2 in Clinical Samples
Archives of Pediatric Infectious Diseases
The laboratory diagnosis of SARS-CoV-2 should be done to confirm coronavirus disease 2019 (COVID-19) in suspected patients. Although several diagnostic methods have been developed in this regard, their accuracy for clinical application is not very clear yet. To compare the diagnostic value of laboratory tests for the detection of COVID-19 infection, this study provides an upcoming review of the newly developed detection methods. Sensitivity, specificity, detection limit, and turnaround time of these methods are compared and challenges for their application in clinical settings are reviewed. PubMed and Google Scholar web sites were used for the systematic search until April 9, 2020 to identify the published studies based on the following keywords: "Detection", "Coronavirus 2019", "SARS-CoV-2", and "Sensitivity". Out of 526 results, a total of 54 articles, including 46 studies on detection methods, were considered eligible for the review. The results showed that most of the proposed tests focused on molecular methods, while immunological and point-of-care tests were investigated in 13 studies. There were also a few commercial automated methods for the qualitative detection of SARS-CoV-2 in clinical samples, most of which are not examined in the current review, as no data about their sensitivity and specificity were presented. Although the assessment of publication biases showed that 64% sensitivity and nearly 100% specificity for RT-PCR are close to reality, most of the related reports for serological methods are not valid and further studies are needed to confirm their utility in clinical settings. Moreover, the RT-PCR test alone cannot act as a gold standard because of bias in measurements. Therefore, antibody tests and other proposed methods could be used as supplementary diagnostic tests to improve RT-PCR accuracy. Although clinical findings are invaluable, in many cases, they can provide more valuable supportive data than serological tests.
PLOS ONE, 2023
Background Nasopharyngeal antigen Rapid Diagnostic Tests (RDTs), saliva RT-PCR and nasopharyngeal (NP) RT-PCR have shown different performance characteristics to detect patients infected by SARS-CoV-2, according to the viral load (VL)-and thus transmissibility. Methods In October 2020, we conducted a prospective trial involving patients presenting at testing centres with symptoms of COVID-19. We compared detection rates and performance of RDT, saliva PCR and nasopharyngeal (NP) PCR, according to VL and symptoms duration. Results Out of 949 patients enrolled, 928 patients had all three tests performed. Detection rates were 35.2% (95%CI 32.2-38.4%) by RDT, 39.8% (36.6-43.0%) by saliva PCR, 40.1% (36.9-43.3%) by NP PCR, and 41.5% (38.3-44.7%) by any test. For those with viral loads (VL) �10 6 copies/ml, detection rates were 30.3% (27.3-33.3), 31.4% (28.4-34.5), 31.5% (28.5-34.6), and 31.6% (28.6-34.7%) respectively. Sensitivity of RDT compared to NP PCR was 87.4% (83.6-90.6%) for all positive patients, 94.5% (91.5-96.7%) for those with VL�10 5 and 96.5% (93.6-98.3%) for those with VL�10 6. Sensitivity of STANDARD-Q ® , Panbio™ and COVID-VIRO ® Ag tests were 92.9% (86.4-96.9%), 86.1% (78.6-91.7%) and 84.1% (76.9-89.7%), respectively. For those with VL�10 6 , sensitivity was 96.6% (90.5-99.3%), 97.8% (92.1-99.7%) and 95.3% (89.4-98.5%) respectively. No patient with VL<10 4 was detected by RDT. Specificity of RDT was 100% (99.3-100%) compared to any PCR. RDT sensitivity was similar <4 days (87.8%, 83.5-91.3%) and �4 days (85.7%, 75.9-92.6%) after symptoms
Infection
Molecular diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by real-time reverse transcription polymerase chain reaction (RT-PCR) in respiratory specimens is considered the gold standard method. This method is highly sensitive and specific but it has some limitations such as being expensive and requiring special laboratory equipment and skilled personnel. RapidFor™ Antigen Rapid Test Kit is a commercially available Ag-RDT which is produced in Turkey and designed to detect the nucleocapsid antigen of SARS-CoV-2 in nasopharyngeal swab samples. The aim of this study was to evaluate the performance of this novel SARS-CoV-2 antigen detection considering the RT-PCR method as the gold standard. Four hundred forty-four nasopharyngeal swab samples which were collected from the patients who met clinical criteria of COVID-19 from ten centers in Turkey between September 2020 and February 2021 were included in the study. All the nasopharyngeal swab samples were tested for SARS-CoV-2 RNA using commercial RT-PCR kits (Bioeksen and A1 Lifesciences, İstanbul, Turkey) according to the manufacturer's instructions. Viral loads were assessed according to the cycle threshold (Ct) values. RapidFor™ SARS-CoV-2 antigen test (Vitrosens Biotechnology, Istanbul, Turkey) was used to investigate the presence of SARS-CoV-2 antigen in all samples following the manufacturer's instructions. Out of 444 nasopharyngeal swab samples tested, 346 (77.9%) were positive and 98 (22.1%) were negative for SARS-CoV-2 RNA by RTPCR. Overall sensitivity of the RapidFor™. Antigen Rapid Test Kit was 80.3% whereas specificity was found to be 87.8%. Positivity rate of rapid antigen test in samples with Ct values over 25 and below 30 was 82.7%, while it increased to 95.7% in samples 20 ≤ Ct < 25 and reached 100% in samples with Ct values below 20. RapidFor™ SARS-CoV-2 Ag test might be a good choice in the screening of symptomatic and asymptomatic patients and their contacts for taking isolation measures early, with advantages over RT-PCR as being rapid, easy and being applicable in every laboratory and even at point of care.
Journal of Clinical Pathology
AimsTo date, reverse transcriptase PCR (RT-PCR) on nasopharyngeal swabs is the ‘gold standard’ approach for the diagnosis of COVID-19. The need to develop easy to use, rapid, robust and with minimal hands-on time approaches are warranted. In this setting, the Idylla SARS-CoV-2 Test may be a valuable option. The aim of our study is to evaluate the analytical and clinical performance of this assay on previously tested SARS-CoV-2 people by conventional RT-PCR based approach in different settings, including initial diagnosis and clinical follow-up.MethodsTo evaluate the sensitivity and specificity of the Idylla SARS-CoV-2 Test, we retrieved 55 nasopharyngeal swabs, previously analysed by a fully validated assay, from symptomatic patients or from people who have been in close contact with COVID-19 positive cases. Discordant or high discrepant cases were further analysed by a third technique. In addition, a second subset of 14 nasopharyngeal swab samples with uncertain results (cycle thre...
Open Access Macedonian Journal of Medical Sciences
BACKGROUND: Detection of positive 2019-nCoV nucleic acids by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR)-based assays performed on the upper and lower respiratory samples remains the gold standard for the diagnosis of COVID-19. However, antigen-detecting rapid diagnostic tests can offer a faster (15–30 min) and less expensive way to diagnose active severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection than nucleic acid amplification tests. AIM: Hence, the present study aimed to compare and evaluate the results of different SARS-CoV-2 rapid point-of-care antigen tests with SARS-CoV-2 PCR as a reference method. METHODS: Sixty-five nasopharyngeal swab specimens were collected from attendees of the Reference Laboratory of Egyptian university hospitals. The samples were placed in viral transport medium for RNA extraction. The remaining part of the suspension was stored at −70°C until use for COVID-19 antigen testing. All samples were processed for...
CovidNudge: diagnostic accuracy of a novel lab-free point-of-care diagnostic for SARS-CoV-2
2020
Background Access to rapid diagnosis is key to the control and management of SARS-CoV-2. Reverse Transcriptase- Polymerase Chain Reaction (RT-PCR) testing usually requires a centralised laboratory and significant infrastructure. We describe the development and diagnostic accuracy assessment of a novel, rapid point-of-care RT-PCR test, the DnaNudge platform CovidNudge test, which requires no laboratory handling or sample pre-processing. Methods Nasopharyngeal swabs are inserted directly into a cartridge which contains all reagents and components required for RT-PCR reactions, including multiple technical replicates of seven SARS-CoV-2 gene targets (rdrp1, rdrp2, e-gene, n-gene, n1, n2 and n3) and human ribonuclease P (RNaseP) as a positive control. Between April and May 2020, swab samples were tested in parallel using the CovidNudge direct-to-cartridge platform and standard laboratory RT-PCR using swabs in viral transport medium. Samples were collected from three groups: self-referre...
Detection of SARS-CoV-2 infection by RT-PCR test: factors influencing interpretation of results
VirusDisease
In this current pandemic of coronavirus disease 2019 (COVID-19), prompt interventions in terms of early detection and clinical management along with isolation of positive cases is of utmost importance. This helps to limit not only the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections but also the morbidity and mortality associated with it. Different strategies for screening of COVID-19 in containment zones and noncontainment areas include testing of symptomatic patients and their contacts in fever clinics, hospital-based testing, testing on demand and population-based screening. The choice of tests like reverse-transcription polymerase chain reaction (RT-PCR), rapid antigen testing (RAT) or antibody test depends upon these strategies and also the turnaround time. Currently, RT-PCR is considered the gold standard for COVID-19 detection. This commentary provides the insights and experiences on COVID-19 diagnosis by RT-PCR. The utility of this test is limited by several false positive, false negative and inconclusive results at early stages of infection, scarcity of reagents and lack of well-equipped labs including trained staff. Moreover, appropriate sample collection and transport, standard laboratory protocols, stringent quality control norms, good quality RNA extraction kits, PCR kits with suitable primers can help in improving accuracy of the test results. A careful assessment of clinical, radiological and molecular findings is required for identifying potential cases of COVID-19.
International Journal of Infectious Diseases, 2021
Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre-including this research content-immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.