Background
RT-qPCR is the current recommended laboratory method to diagnose SARS-CoV-2 acute infection, several factors such as requirement of special equipment, time consuming, high cost and skilled staff limit the use of these techniques. A more rapid and high-throughput method is essential.
Rat Cholesterol ELISA ELISA | |
E01A11128 | BlueGene |
Goat Cholesterol ELISA ELISA | |
E01A46041 | BlueGene |
Mouse Cholesterol ELISA ELISA | |
E01A19869 | BlueGene |
Human Cholesterol ELISA ELISA | |
E01A2368 | BlueGene |
Sheep Cholesterol ELISA ELISA | |
E01A98335 | BlueGene |
Methods
We analyzed clinical data and nasopharyngeal samples, collected during September 2020, from patients attended at the emergency department of a secondary hospital and in two primary healthcare centers in Madrid. The performance of the Panbio COVID-19 AG Rapid Test Device for the detection of SARS-CoV-2 antigen was compared to RT-qPCR.
Results
255 nasopharyngeal swabs, including 150 from the emergency department and 105 from primary helthcare centers, were tested. 184 patients were symptomatic (72.1 %). Amongst the 60 positive RT-qPCR samples, 40 were detected by the rapid antigen test, given an overall sensitivity of 73.3 %. All the samples detected positive with the rapid antigen test were also positive with RT-qPCR. The median cycle threshold was 23.28 (IQR 18.5–30.16). Patients with less than seven days onset of symptoms showed a higher viral load, and sensitivity for rapid antigen test (86.5 %), compared to those with more days (sensitivity of 53.8 %)(p < 0.004).
Conclusions
The rapid antigen test evaluated in this study showed a high sensitivity and specificity in samples obtained during the first week of symptoms and with high viral loads. This assay seems to be an effective strategy for controlling the COVID-19 pandemic for the rapid identification and isolation of SARS-CoV-2 infected patients.
1. Introduction
Ensuring accurate diagnosis is essential to limit the spread of SARS-CoV-2 and for the clinical management of COVID-19. Although real-time reverse transcription polymerase chain reaction (RT-qPCR) is the currently recommended laboratory method to diagnose SARS-CoV-2 acute infection, several factors such as requirement of special equipment, time consuming, high cost and skilled staff limit the use of these molecular techniques. A more rapid and high-throughput method is in growing demand.
Until now, the use of antigen detection tests alone had been ruled out and not recommended due to their low sensitivity . Previously in the first wave, several easy to perform rapid antigen detection tests were developed as the first line of diagnostic. However, the results obtained were not good enough.
Abstract
Background: Antigen-detecting rapid diagnostic tests (Ag-RDTs) for the detection of SARS-CoV-2 offer new opportunities for testing in the context of the COVID-19 pandemic. Nasopharyngeal swabs (NPS) are the reference sample type, but oropharyngeal swabs (OPS) may be a more acceptable sample type in some patients.
Methods: We conducted a prospective study in a single screening center to assess the diagnostic performance of the Panbio COVID-19 Ag Rapid Test (Abbott) on OPS compared with reverse-transcription quantitative PCR (RT-qPCR) using NPS during the second pandemic wave in Switzerland.
Results: 402 outpatients were enrolled in a COVID-19 screening center, of whom 168 (41.8%) had a positive RT-qPCR test. The oropharyngeal Ag-RDT clinical sensitivity compared to nasopharyngeal RT-qPCR was 81% (95%CI: 74.2-86.6). Two false positives were noted out of the 234 RT-qPCR negative individuals, which resulted in a clinical specificity of 99.1% (95%CI: 96.9-99.9) for the Ag-RDT. For cycle threshold values ≤ 26.7 (≥ 1E6 SARS-CoV-2 genomes copies/mL, a presumed cut-off for infectious virus), 96.3% sensitivity (95%CI: 90.7-99.0%) was obtained with the Ag-RDT using OPS.
Interpretation: Based on our findings, the diagnostic performance of the Panbio™ Covid-19 RDT with OPS samples, if taken by a trained person and high requirements regarding quality of the specimen, meet the criteria required by the WHO for Ag-RDTs (sensitivity ≥80% and specificity ≥97%) in a high incidence setting in symptomatic individuals.
Paraffin Wax | |||
P191410 | |||
Paraffin wax pellets | |||
GRM10702-2KG | |||
Paraffin wax pellets | |||
GRM10702-500G | |||
Paraffin wax Pellets | |||
GRM10702W-2KG | |||
Paraffin wax Pellets | |||
GRM10702W-500G |