Validation Study for PathogenDx EnviroX-Rv Assay for the Detection of SARS-CoV-2 from Stainless Steel Environmental Surface Swabs Performance Tested MethodSM 122003.

Background: The PathogenDx EnviroX-Rv uses endpoint PCR + DNA microarray technology to detect SARS-CoV-2, the causative agent of COVID-19, from stainless-steel environmental sample swabs.

Objective: To validate the PathogenDx EnviroX-Rv assay as part of the Emergency Response Validation (ERV) Performance Tested Method(s)SM (PTM) program.

Method: The PathogenDx EnviroX-Rv assay was evaluated for specificity using in silico analysis of ≥41 000 SARS-CoV-2 sequences and over 50 exclusivity organisms (both near neighbors and background organisms). The candidate method was evaluated in an unpaired study design for one environmental surface (stainless steel) and compared to the US Centers for Disease Control and Prevention (CDC) 2019-Novel Coronavirus (2019-nCoV) Real-Time-Polymerase Chain Reaction (RT-PCR) Diagnostic Panel, Instructions for Use (Revision 4, Effective 6/12/2020).

Results: Results of the in silico analysis demonstrated the high specificity of the method in being able to detect target SARS-CoV-2 sequences and discriminate them from near neighbors and environmental background organisms. In the matrix study, the candidate method demonstrated a statistically significant difference when compared to the results of the CDC method utilized in this study, with the candidate method resulting in more positive replicates as it only requires one target to be present for a positive sample.

Conclusions: The EnviroX-Rv assay rapidly and accurately detected SARS-CoV-2 RNA on environmental swabs from stainless-steel surfaces at a concentration of 2000 genomic copies per 2 × 2" test area.

Highlights: The EnviroX-Rv assay employs dual PCR and hybridization techniques to provide highly accurate results when detecting SARS-CoV-2 from surfaces.