%0 Journal Article
%T Melting curve analysis reveals false-positive norovirus detection in a molecular syndromic panel.
%A Matic N
%A Lawson T
%A Young M
%A Jang W
%A Bilawka J
%A Gowland L
%A Ritchie G
%A Leung V
%A Payne M
%A Stefanovic A
%A Romney MG
%A Lowe CF
%J J Clin Virol
%V 173
%N 0
%D 2024 Aug 27
%M 38820917
%F 14.481
%R 10.1016/j.jcv.2024.105697
%X <B>BACKGROUND: </B>Molecular syndromic panels can improve rapidity of results and ease clinical laboratory workflow, although caution has been raised for potential false-positive results. Upon implementation of a new panel for infectious diarrhea (BioFire® FilmArray® Gastrointestinal [GI] Panel, bioMérieux) in our clinical laboratory, a higher than expected number of stool samples with norovirus were detected.<BR><B>OBJECTIVE: </B>The goal of this study was to investigate positive percent agreement and the false-positive rate of norovirus detected by the multiplex BioFire GI panel compared to a singleplex commercial assay.<BR><B>METHODS: </B>From October 2023 to January 2024, all prospective stool samples with a positive norovirus result by BioFire had melting curves reviewed manually using the BioFire FilmArray Torch System. Stool samples further underwent testing by a supplementary real-time RT-PCR assay (Xpert® Norovirus, Cepheid) for comparative analysis.<BR><B>RESULTS: </B>Of the 50 stool samples with norovirus detected by BioFire, 18 (36 %) tested negative by Xpert (deemed "false-positives"). Furthermore, melting curve analysis revealed nearly all of these samples had atypical melting curve morphologies for the "Noro-1" target on BioFire (16/18, 89 %), which was statistically significant (Odds Ratio 173.2, 95 % CI [22.2, 5326.9], p < 0.0001). Stool samples with multiple pathogens detected by BioFire including norovirus were not more likely to produce false-positive norovirus results (Odds Ratio 1, 95 % CI [0.3, 3.3], p = 1).<BR><B>CONCLUSIONS: </B>Although not described in the manufacturer's Instructions for Use, we propose routine manual review of melting curves for the BioFire GI panel prior to reporting, to mitigate potential false-positive norovirus results.