Efficacy of Xpert MTB/RIF Ultra in diagnosing tuberculosis meningitis A systematic review and meta-analysis

Background: This study aimed to assess whether Xpert MTB/RIF Ultra (Xpert Ultra) can effectively diagnose tuberculosis meningitis (TBM) and to simultaneously compare its effectiveness with Xpert in diagnosing TBM in the same population. Methods: On August 12, 2020, Wanfang Database, China National Knowledge Infrastructure, Embase, Cochrane Library, and PubMed were searched for studies evaluating the diagnostic accuracy of Xpert Ultra for TBM. Then, we assessed the efficacy of Xpert Ultra against a composite reference standard and culture. If applicable, we also examined the diagnostic efficacy of Xpert in the same population. Heterogeneity was then explored by meta-regression, subgroup, and sensitivity analyses. Results: Six studies containing 601 specimens reported the diagnostic efficacy of Xpert Ultra for TBM, with a composite reference standard. No study had compared the efficacy between Xpert Ultra and culture. The pooled sensitivity of Xpert Ultra was 64% (95% confidence interval [CI]: 45-80), and the I-2 value was 86% (95% CI: 76-96); its specificity for TBM was consistently 100%. In the same population, 5 studies compared the diagnostic efficacy between Xpert Ultra and Xpert for TBM. The pooled sensitivity of Xpert Ultra and Xpert was 68% (95% CI: 46-84; I-2 = 87%) and 37% (95% CI: 25-50; I-2 = 72%), respectively. The studies were significantly heterogeneous in terms of sensitivity but not heterogeneous in specificity. Conclusions: Xpert Ultra was more sensitive than Xpert, but both were specific (100%). Therefore, Xpert Ultra had an excellent diagnostic efficacy for TBM, and it could be the preferred initial test for TBM.