Performance of the RT-LAMP-based eazyplex® SARS-CoV-2 as a novel rapid diagnostic test

Area of Science:

• Molecular Diagnostics
• Virology
• Infectious Disease

Background:

• Rapid and easy-to-perform diagnostic assays for severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) are crucial for timely isolation of infected individuals.
• Current molecular diagnostic methods can be time-consuming and require specialized laboratory settings.

Purpose of the Study:

• To evaluate the performance of the CE-approved eazyplex® SARS-CoV-2 assay, a real-time reverse transcription loop-mediated isothermal amplification (RT-LAMP) test.
• To assess its utility for rapid identification of SARS-CoV-2 N and ORF8 genes directly from patient swabs without RNA extraction.

Main Methods:

• The eazyplex® SARS-CoV-2 assay was evaluated using oropharyngeal and nasal swabs from 100 SARS-CoV-2 positive and 50 negative patients.
• Samples were initially tested by RT-PCR (NeuMoDx™), and an aliquot was directly analyzed by eazyplex® SARS-CoV-2 after dilution in a liquefying solution.
• Analytical sensitivity was determined using quantified virus stock dilutions.

Main Results:

• The eazyplex® SARS-CoV-2 assay demonstrated a positive percent agreement (PPA) of 97.4% with RT-PCR for samples with Ct values ≤ 28.
• No false positive results were observed.
• Median time to positivity was under 17 minutes for both target genes, with analytical sensitivity at 3.75 TCID50/mL.

Conclusions:

• The eazyplex® SARS-CoV-2 assay is a rapid and accurate tool for identifying SARS-CoV-2, particularly in samples with high viral loads.
• Its ease of use and speed make it suitable for near-patient testing in diverse settings outside of traditional molecular laboratories.