Background In a hospital setting, there is a need for rapid detection of SARS-CoV-2 to guide isolation measures and targeted admission. Aim First, we evaluated the diagnostic performance of five SARS-CoV-2 rapid nucleocapsid protein antigen detection (RAD) assays (Biosynex, Biotical, Orient Gene, Panbio, SD Biosensor). Secondly, we described the performance and impact of the implementation of the SD Biosensor assay at our emergency department. Methods Sensitivity and specificity of the five RAD assays were analyzed on 100 respiratory samples: 60 real-time reverse-transcriptase-polymerase chain reaction (rRT-PCR) confirmed SARS-CoV-2 positive samples, 24 SARS-CoV-2 RNA negative samples and 16 samples positive for other respiratory pathogens. We adapted the manufacturer’s protocol, to validate the antigen tests on transport media used for rRT-PCR in our routine practice. The SD Biosensor RAD assay was implemented as screening method for rapid diagnosis and targeted admission. Findings Sensitivity of the included RAD assays ranged from 88.9% to 100% for samples with Ct <26, specificity from 46.2% to 100%. During the implementation period, 4195 RAD tests were performed. Due to the rapid RAD result, 157 patients were transferred directly to the COVID-19 cohort instead of the regular ward (n=47) or the temporary COVID-19 ward (n=110). Conclusion The SD Biosensor, Biotical and Panbio SARS-CoV-2 antigen tests had an acceptable overall performance and seem to be able to detect most of the contagious patients. In the context of high prevalence of SARS-CoV-2, RAD tests can be used as a rapid screening tool, to guide infection prevention measures and aid targeted admission.
Objective Analytical validation of newly released SARS-CoV-2 antibody assays in the clinical laboratory is crucial to ensure sufficient performance in respect to its intended use. We aimed to assess analytical and diagnostic performance of 8 (semi-)quantitative assays detecting anti-nucleocapsid IgG (Euroimmun, Id-Vet) or total Ig (Roche), anti-spike protein IgG (Euroimmun, Theradiag, DiaSorin, Thermo Fisher) or both (Theradiag) and 2 rapid lateral flow assays (LFA) (AAZ-LMB and Theradiag). Methods Specificity was evaluated using a cross-reactivity panel of 85 pre-pandemic serum samples. Sensitivity was determined at both the manufacturer's and a 95% specificity cut-off level, using 81 serum samples of patients with a positive rRT-PCR. Sensitivity was determined in function of time post symptoms onset. Results Specificity for all assays ranged from 92.9% to 100% (Roche and Thermo Fisher) with the exception of the Theradiag IgM LFA (82.4%). Sensitivity in asymptomatic patients ranged between 41.7% and 58.3%. Sensitivity on samples taken <10 days since symptom onset was low (23.3%–66.7%) and increased on samples taken between 10 and 20 days and > 20 days since symptom onset (80%–96% and 92.9%–100%, respectively). From 20 days after symptom onset, the Roche, Id-vet and Thermo Fisher assays all met the sensitivity (>95%) and specificity (>97%) targets determined by the WHO. Antibody signal response was significantly higher in the critically ill patient group. Conclusion Antibody detection can complement rRT-PCR for the diagnosis of COVID-19, especially in the later stage, or in asymptomatic patients for epidemiological purposes. Addition of IgM in LFAs did not improve sensitivity.
On the first of January 2019, the European Committee on Antimicrobial Susceptibility Testing, EUCAST, introduced the concept of "area of technical uncertainty" (ATU). The aim was to report on the incidence of ATU test results in a selection of common bacterial species and the subsequent impact on antimicrobial resistance categorization and workload. A retrospective analysis of clinical samples collected from February 2019 until November 2019 was performed. Susceptibility to amoxicillin-clavulanic acid and piperacillin-tazobactam in Enterobacterales (Escherichia spp., Klebsiella spp., Proteus spp.), piperacillin-tazobactam in Pseudomonas aeruginosa, and amoxicillin-clavulanic acid and cefuroxime in Haemophilus influenzae was studied. Disk diffusion antibiotic susceptibility testing was read and interpreted by ADAGIO 93400 automated system (Bio-Rad, France). In case of an inhibition zone in the ATU, strains were retested using gradient minimal inhibitory concentration method (Etest, BioMérieux, France). Overall, 14,164 isolate-antibiotic combinations were tested in 7922 isolates, resulting in 1204 (8.5%) disk zone diameters in the ATU region. Retesting of ATUs with Etest resulted in a category change from S to R for amoxicillin-clavulanic acid in 63/498 (12.7%) of Escherichia spp., 2/58 (3.4%) of Klebsiella spp., 2/37 (5.4%) of Proteus spp., and 6/125 (4.8%) of Haemophilus influenzae. For piperacillin-tazobactam, a category change from S to R was found in 33/92 (35.9%) of Pseudomonas aeruginosa. We conclude that ATU testing has a substantial impact on the correct interpretation of antimicrobial resistance, at the expense of turn-around time and with the cost of additional workload.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.