Related Experiment Video
Updated: Jul 20, 2025
Multiplexed Isothermal Amplification Based Diagnostic Platform to Detect Zika, Chikungunya, and Dengue 1
Published on: March 13, 2018
Multiplex real-time PCR FilmArray performance in the diagnosis of meningoencephalitis: lights and shadows
Néstor López1, Genoveva Cuesta2, Sara Rodríguez-Vega3
1Infectious Diseases Department, Hospital Clínic-IDIBAPS, Barcelona, Spain.
Purpose:
We aimed to evaluate the performance of the FilmArray (FA) meningitis/encephalitis (ME) panel. Secondarily, we analyzed the false positive (FP) and false negative (FN) results, as well as the predictive values of the technique, regarding the cerebrospinal fluid (CSF) characteristics.
Methods:
FA is a multiplex real-time PCR detecting 14 of the most common ME pathogens in CSF. All FA performed at our hospital (2018-2022) were retrospectively reviewed. FA was compared to conventional techniques and its performance was assessed based on the final diagnosis of the episode.
Results:
FA was performed in 313 patients with suspicion of ME. Most patients had altered mental status (65.2%) and fever (61%). Regarding CSF characteristics, 49.8% and 53.7% presented high CSF proteins and pleocytosis, respectively. There were 84 (26.8%) positive FA results, mainly for HSV-1 (10.9%), VZV (5.1%), Enterovirus (2.6%), and S. pneumoniae (1.9%). In the 136 cases where both FA and routine methods were performed, there was a 25.7% lack of agreement. We identified 6.6% FN results, but 28.6% FP, mainly due to HSV-1. This resulted in a high negative predictive value (NPV) of 93.4%, but a positive predictive value (PPV) of 73%. Remarkably, PPV as low as 36.9%, and 70.2%, were found in cases without pleocytosis, or lack of high CSF protein levels, respectively.
Conclusion:
FA was associated with high NPV, but frequent FP results and low PPV, particularly for HSV-1, and especially in patients without high CSF protein levels or pleocytosis.
Insights
The FilmArray meningitis/encephalitis panel offers high negative predictive value but struggles with frequent false positives, particularly for HSV-1, impacting its positive predictive value in certain patient groups.
Area of Science:
- Clinical Microbiology
- Molecular Diagnostics
- Infectious Diseases
Background:
- Meningitis and encephalitis (ME) are critical neurological conditions requiring rapid and accurate diagnosis.
- Multiplex PCR panels offer a potential advancement over conventional diagnostic methods for ME pathogens.
Purpose of the Study:
- To evaluate the performance of the FilmArray (FA) meningitis/encephalitis (ME) panel.
- To analyze false positive (FP) and false negative (FN) rates and predictive values of the FA-ME panel.
- To assess the influence of cerebrospinal fluid (CSF) characteristics on FA-ME panel performance.
Main Methods:
- Retrospective review of 313 patients undergoing FA-ME panel testing between 2018-2022.
- Comparison of FA-ME panel results with conventional diagnostic techniques.
- Assessment of panel performance based on final clinical diagnosis and CSF parameters.
Main Results:
- The FA-ME panel was positive in 26.8% of cases, with HSV-1 being the most common pathogen detected.
- A significant lack of agreement (25.7%) was observed between FA-ME and routine methods.
- High rates of false positives (28.6%) were noted, particularly for HSV-1, leading to a low positive predictive value (PPV) of 73% (as low as 36.9% without pleocytosis).
Conclusions:
- The FA-ME panel demonstrates a high negative predictive value (NPV) but is limited by frequent false positives and a low PPV.
- The diagnostic utility of the FA-ME panel is diminished in patients lacking pleocytosis or elevated CSF protein levels.
- Clinical interpretation of FA-ME results should consider CSF characteristics to mitigate the impact of false positives, especially for HSV-1.
