Abstract：
BACKGROUND: 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.
OBJECTIVE: 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.
METHODS: 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.
RESULTS: 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).
CONCLUSIONS: 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.
OBJECTIVE: 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.
METHODS: 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.
RESULTS: 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).
CONCLUSIONS: 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.
摘要：
背景：分子综合征小组可以提高结果的快速性并简化临床实验室工作流程，尽管对潜在的假阳性结果表示谨慎。在实施新的感染性腹泻小组(BioFire®FilmArray®胃肠[GI]小组，bioMérieux)在我们的临床实验室，检测到的诺如病毒粪便样本数量高于预期。
目的：本研究的目的是调查多重BioFireGI小组检测到的诺如病毒的阳性百分比一致性和假阳性率，与单一商业测定相比。
方法：从2023年10月至2024年1月，所有BioFire诺如病毒阳性结果的预期粪便样本均使用BioFireFilmArrayTorch系统手动审查了熔解曲线。粪便样本进一步通过补充实时RT-PCR检测(Xpert®诺如病毒，造父变星)进行比较分析。
结果：在BioFire检测到的50个含有诺如病毒的粪便样本中，18（36%）由Xpert检测为阴性（被认为是“假阳性”）。此外，熔解曲线分析显示，几乎所有这些样品都具有BioFire上的“Noro-1”目标的非典型熔解曲线形态（16/18，89％），具有统计学意义(赔率比173.2，95%CI[22.2，5326.9]，p<0.0001)。通过BioFire检测到的包括诺如病毒在内的多种病原体的粪便样本不太可能产生假阳性诺如病毒结果（赔率比1，95％CI[0.3，3.3]，p=1)。
结论：尽管制造商的使用说明中没有描述，我们建议在报告之前对BioFireGI面板的熔解曲线进行常规手动审查，以减轻潜在的假阳性诺如病毒结果。
目的：本研究的目的是调查多重BioFireGI小组检测到的诺如病毒的阳性百分比一致性和假阳性率，与单一商业测定相比。
方法：从2023年10月至2024年1月，所有BioFire诺如病毒阳性结果的预期粪便样本均使用BioFireFilmArrayTorch系统手动审查了熔解曲线。粪便样本进一步通过补充实时RT-PCR检测(Xpert®诺如病毒，造父变星)进行比较分析。
结果：在BioFire检测到的50个含有诺如病毒的粪便样本中，18（36%）由Xpert检测为阴性（被认为是“假阳性”）。此外，熔解曲线分析显示，几乎所有这些样品都具有BioFire上的“Noro-1”目标的非典型熔解曲线形态（16/18，89％），具有统计学意义(赔率比173.2，95%CI[22.2，5326.9]，p<0.0001)。通过BioFire检测到的包括诺如病毒在内的多种病原体的粪便样本不太可能产生假阳性诺如病毒结果（赔率比1，95％CI[0.3，3.3]，p=1)。
结论：尽管制造商的使用说明中没有描述，我们建议在报告之前对BioFireGI面板的熔解曲线进行常规手动审查，以减轻潜在的假阳性诺如病毒结果。
