Etiologic diagnosis of suspected tuberculous meningitis by multiplex PCR of cerebrospinal fluid.

Distinguishing tuberculous meningitis (TBM) from other causes of meningitis remains challenging in high-burden settings because clinical features overlap and existing assays often delay etiologic confirmation. We evaluated MeltArray CNS, a highly multiplexed PCR assay targeting 85 meningitis-associated pathogens, for etiologic diagnosis in patients with suspected meningitis. Analytical performance was assessed using pre-characterized targets. MeltArray was compared head-to-head with metagenomic next-generation sequencing (mNGS) in 79 cerebrospinal fluid (CSF) specimens, with discrepant results adjudicated by Sanger sequencing, and was then prospectively evaluated in 255 consecutive patients with suspected meningitis. Biomarker-based models using routine CSF and serum parameters were also explored. The assay achieved limits of detection of 5 copies/reaction for IMPORTANCE: Tuberculous meningitis (TBM) is a life-threatening infection that requires a rapid and accurate diagnosis to guide effective treatment. Conventional diagnostic methods are often slow or insufficiently sensitive, leading to delays in therapy and potential exposure to unnecessary medications. In this study, we evaluated a rapid multiplex molecular assay for patients with suspected tuberculous meningitis. Rapid detection of