title: Appropriate use of the Xpert® MTB/RIF assay in suspected tuberculous meningitis.
abstract: We disagree with the recommendation by the World Health Organization to use Xpert(®) MTB/RIF on cerebrospinal fluid for the initial diagnosis of tuberculous meningitis (TBM). TBM is a devastating disease requiring empirical treatment even when the probability of disease is low. We suggest that a useful TBM diagnostic test needs a negative predictive value (NPV) of ⩾ 99% so that empirical treatment can be stopped safely. The NPV of Xpert is around 84%, making a negative test of limited value. While better tests are awaited, a composite score, possibly combining Xpert with clinical variables and with high NPV, should be constructed and validated prospectively.
authors: <sup>*</sup>University of Cape Town, Cape Town, South Africa;
authors: T H
authors: TH
authors: Boyles
authors: <sup>†</sup>Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Viet Nam.
authors: G E
authors: GE
authors: Thwaites
mesh_terms: D000904:Antibiotics, Antitubercular / Q000627:therapeutic use; D002555:Cerebrospinal Fluid / Q000382:microbiology; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013048:Specimen Handling; D014390:Tuberculosis, Meningeal / Q000175:diagnosis* / Q000188:drug therapy
chemical_list: D000904:Antibiotics, Antitubercular