Clinical Significance of Positive Results of the BioFire Cerebrospinal Fluid FilmArray Meningitis/Encephalitis Panel at a Tertiary Medical Center in the United States.

CONTEXT.—: The FilmArray Meningitis/Encephalitis (ME) panel is the first US Food and Drug Administration-cleared multiplex polymerase chain reaction panel for the detection of central nervous system infections. While the assay's performance characteristics have been described, the real-world significance of positive results has not been fully characterized. OBJECTIVE.—: To evaluate the clinical significance of positive ME panel results in a tertiary care medical center in New York, New York. DESIGN.—: Four physicians independently performed retrospective clinical assessments of all positive ME panel results at Columbia University Irving Medical Center, including the Children's Hospital of New York, during an 18-month period. Each reviewer determined the likelihood of central nervous system infection for all cases and whether cases fit Brighton diagnostic criteria for meningitis, encephalitis, or meningoencephalitis. RESULTS.—: Among 119 cases, there was 75% positive agreement (95% CI, 54%-89%) between ME panel results and clinical consensus, which varied among panel targets. CONCLUSIONS.—: The ME panel showed good agreement with expert clinical consensus for patients presenting with acute meningitis/encephalitis. Factors contributing to clinically insignificant ME positive results included low pretest probability, traumatic lumbar puncture, specimen contamination, and detection of incidental viral targets such as human herpesvirus 6. Notably, the ME panel detected more than twice the number of cases of bacterial meningitis detected by culture alone, particularly among patients receiving empiric antimicrobial therapy before lumbar puncture. Appropriate test use and contextual interpretation of results are critical to leveraging the advantages of the platform while avoiding potential pitfalls.