Evaluation of Discordant Results Between FilmArray Meningitis/Encephalitis Panel and Conventional Testing in Pediatric Patients: A Multisite Retrospective Cohort Study

Abstract

Abstract Background The FilmArray Meningitis/Encephalitis panel (MEP) has an 11% false-positive and 2.2% false-negative rate compared with conventional testing. We describe clinical characteristics, treatment decisions, and outcomes in children with discordant results between MEP and conventional testing. Methods We conducted a multisite review of patients ≤ 18 years with suspected central nervous system infection and positive results by MEP or conventional testing (cerebrospinal fluid [CSF] culture, herpes simplex virus [HSV] polymerase chain reaction (PCR), and enterovirus [EV] PCR). Descriptive results are provided for patients with discordant results. Comparison between group 1 (MEP and CSF culture positive) and group 2 (MEP positive, CSF culture negative, or showing a different pathogen) was made by Mann-Whitney test for continuous and Fisher’s test for categorical variables. Results A total of 355 patients had at least one pathogen identified. More than half of patients with bacterial pathogens identified that are included in the MEP had discordant results (30/52; 58%). There were 28 samples with bacterial pathogen identified on MEP only, 1 with different bacterial pathogens on MEP and culture, and 1 with Escherichia coli identified on CSF culture only. Patients in group 1 were more likely to have CSF pleocytosis, elevated CSF protein, and decreased CSF glucose than group 2 (P < .05). Two patients were HSV positive by MEP while HSV negative by PCR. Ten patients had discordant results between MEP and EV PCR. Conclusions Discordant results between MEP and conventional testing are common. Treatment decisions based on a positive MEP should be made in the appropriate clinical context.