Using cerebrospinal fluid for the diagnosis of tuberculous meningitis with GeneXpert.

We read with interest the systematic review by C. Denkinger and co-workers on the use of the Xpert MTB/ RIF assay for diagnosing extrapulmonary tuberculosis (TB) [1], particularly in light of World Health Organization (WHO) endorsement of Xpert MTB/RIF and its recent policy statement on extrapulmonary TB [1–3]. Given the severe clinical course and high mortality associated with TB meningitis, combined with the lack of TB culture capacity in much of the developing world, WHO has endorsed testing cerebrospinal fluid (CSF) with the automated Xpert MTB/RIF assay as a first-line test over conventional microscopy in patients with suspected TB meningitis [2]. This policy recommendation came as a ‘‘strong recommendation given the urgency of rapid diagnosis’’ despite the ‘‘very low quality of evidence’’ [2].