Performance of the RT-LAMP-based eazyplex® SARS-CoV-2 as a novel rapid diagnostic test.
J Clin Virol
; 138: 104817, 2021 05.
Article
in English
| MEDLINE | ID: covidwho-1279625
ABSTRACT
BACKGROUND:
Diagnostic assays for severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) that are easy to perform and produce fast results are essential for timely decision making regarding the isolation of contagious individuals.OBJECTIVE:
We evaluated the CE-approved eazyplex® SARS-CoV-2, a ready-to-use real time RT-LAMP assay for identification of the SARS-CoV-2â¯N and ORF8 genes from swabs in less than 30â¯min without RNA extraction. STUDYDESIGN:
Oropharyngeal and nasal swabs from 100 positive and 50 negative patients were inoculated into 0.9 % saline and tested by NeuMoDx™ RT-PCR. An aliquot was diluted fivefold in Copan sputum liquefying (SL) solution and directly analyzed by eazyplex® SARS-CoV-2. In addition, 130 patient swabs were prospectively tested with both methods in parallel. Analytical sensitivity of the assay was determined using virus stock dilutions.RESULTS:
Positive percent agreement (PPA) between the eazyplex® SARS-CoV-2 and RT-PCR was 74 % for samples with Ct values < 35. When using a Ct cut-off ≤ 28 the PPA increased to 97.4 %. In the prospective part of the study overall PPA of the eazyplex® kit was 66.7 % but increased to 100 % when only Ct values ≤ 28 were considered. There were no false positive results. The median time to positivity was 12.5â¯min for the N gene and 16.75â¯min for ORF8. Analytical sensitivity was 3.75 TCID50/mL. 105 virus copies/mL were reproducibly detected.CONCLUSION:
The eazyplex® SARS-CoV-2 is a rapid assay that accurately identifies samples with high viral loads. It may be useful for near-patient testing outside of a molecular diagnostic laboratory.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Oropharynx
/
RNA, Viral
/
Nasopharynx
/
COVID-19 Nucleic Acid Testing
/
SARS-CoV-2
/
COVID-19
Type of study:
Diagnostic study
/
Experimental Studies
/
Observational study
/
Prognostic study
Limits:
Humans
Language:
English
Journal:
J Clin Virol
Journal subject:
Virology
Year:
2021
Document Type:
Article
Affiliation country:
J.jcv.2021.104817
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