Evaluation of the BioFire® FilmArray® Meningitis/Encephalitis panel in an adult and pediatric Ugandan population

Background

Meningitis causes significant mortality in sub-Saharan Africa and limited diagnostics exist. We evaluated the utility of the BioFire® FilmArray® Meningitis/Encephalitis multiplex PCR panel (BioFire ME) in HIV-infected adults and HIV-infected and uninfected children presenting with suspected meningitis in Uganda.

Methods

We tested cerebrospinal fluid (CSF) using a stepwise meningitis diagnostic algorithm including BioFire ME. We determined the diagnostic performance of BioFire ME for cryptococcal meningitis, using cryptococcal antigen (CrAg) and CSF culture as reference standards, and assessed other central nervous system (CNS) pathogens identified by the panel.

Results

We evaluated 328 adult and 42 pediatric CSF specimens using BioFire ME. Of the adult CSF samples tested, 258 were obtained at baseline, and 70 were obtained from repeat lumbar punctures in cryptococcal meningitis. For Cryptococcus, sensitivity was 82%, specificity was 98%, PPV was 98%, and NPV was 79% in baseline specimens using CSF CrAg as the reference standard. Among follow-up specimens, a negative BioFire ME for Cryptococcus predicted CSF culture sterility with 84% NPV. Overall sensitivity was decreased at low fungal burdens: 29% for 0–99 Cryptococcus CFU/mL compared to 94% for ≥100 CFU/mL in baseline specimens. Other pathogens detected included E. Coli, H. influenzae, S. pneumoniae, CMV, enterovirus, HSV, HHV-6, and VZV. Two specimens tested positive for S. pneumoniae and one for Cryptococcus in the pediatric population.

Conclusions

Multiplex PCR is a promising rapid diagnostic test for meningitis in adults and children in resource-limited settings. Cryptococcus at low fungal burdens in CSF may be missed by BioFire ME.