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Purpose: Tuberculous meningitis (TBM) is the most severe form of tuberculosis (TB). Difficulty in diagnosing the condition along with other factors, increases its potential for high morbidity and mortality. Targeted Next Generation Sequencing (tNGS) generates high quality sequence read depths, enabling the identification of low-frequency alleles linked to Drug resistance (DR). The paucibacillary nature of tuberculous meningitis is a challenge for making a definitive diagnosis., Methods: tNGS was performed on 20 cerebrospinal fluid (CSF) samples where, MGIT has shown Positive MTB Cultures. We simultaneously performed pyrosequencing (PSQ) and phenotypic Drug susceptibility testing (pDST) for these 20 samples., Results: Sequencing results (from tNGS and PSQ) were compared with reference standards i.e. pDST. tNGS detected MTB in 7/20 (35%) CSF samples whereas, PSQ detected MTB in 17/20 (85%)., Conclusion: Although tNGS has ability to detect minority variants along with detection of additional targets than PSQ, PSQ remains the diagnostic choice in our tertiary lab., (Copyright © 2024 Indian Association of Medical Microbiologists. Published by Elsevier B.V. All rights reserved.)

Background: Xpert MTB/RIF Ultra (Xpert Ultra) and Xpert MTB/RIF are World Health Organization (WHO)-recommended rapid nucleic acid amplification tests (NAATs) widely used for simultaneous detection of Mycobacterium tuberculosis complex and rifampicin resistance in sputum. To extend our previous review on extrapulmonary tuberculosis (Kohli 2018), we performed this update to inform updated WHO policy (WHO Consolidated Guidelines (Module 3) 2020)., Objectives: To estimate diagnostic accuracy of Xpert Ultra and Xpert MTB/RIF for extrapulmonary tuberculosis and rifampicin resistance in adults with presumptive extrapulmonary tuberculosis., Search Methods: Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, Science Citation Index, Web of Science, Latin American Caribbean Health Sciences Literature, Scopus, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform, the International Standard Randomized Controlled Trial Number Registry, and ProQuest, 2 August 2019 and 28 January 2020 (Xpert Ultra studies), without language restriction., Selection Criteria: Cross-sectional and cohort studies using non-respiratory specimens. Forms of extrapulmonary tuberculosis: tuberculous meningitis and pleural, lymph node, bone or joint, genitourinary, peritoneal, pericardial, disseminated tuberculosis. Reference standards were culture and a study-defined composite reference standard (tuberculosis detection); phenotypic drug susceptibility testing and line probe assays (rifampicin resistance detection)., Data Collection and Analysis: Two review authors independently extracted data and assessed risk of bias and applicability using QUADAS-2. For tuberculosis detection, we performed separate analyses by specimen type and reference standard using the bivariate model to estimate pooled sensitivity and specificity with 95% credible intervals (CrIs). We applied a latent class meta-analysis model to three forms of extrapulmonary tuberculosis. We assessed certainty of evidence using GRADE., Main Results: 69 studies: 67 evaluated Xpert MTB/RIF and 11 evaluated Xpert Ultra, of which nine evaluated both tests. Most studies were conducted in China, India, South Africa, and Uganda. Overall, risk of bias was low for patient selection, index test, and flow and timing domains, and low (49%) or unclear (43%) for the reference standard domain. Applicability for the patient selection domain was unclear for most studies because we were unsure of the clinical settings. Cerebrospinal fluid Xpert Ultra (6 studies) Xpert Ultra pooled sensitivity and specificity (95% CrI) against culture were 89.4% (79.1 to 95.6) (89 participants; low-certainty evidence) and 91.2% (83.2 to 95.7) (386 participants; moderate-certainty evidence). Of 1000 people where 100 have tuberculous meningitis, 168 would be Xpert Ultra-positive: of these, 79 (47%) would not have tuberculosis (false-positives) and 832 would be Xpert Ultra-negative: of these, 11 (1%) would have tuberculosis (false-negatives). Xpert MTB/RIF (30 studies) Xpert MTB/RIF pooled sensitivity and specificity against culture were 71.1% (62.8 to 79.1) (571 participants; moderate-certainty evidence) and 96.9% (95.4 to 98.0) (2824 participants; high-certainty evidence). Of 1000 people where 100 have tuberculous meningitis, 99 would be Xpert MTB/RIF-positive: of these, 28 (28%) would not have tuberculosis; and 901 would be Xpert MTB/RIF-negative: of these, 29 (3%) would have tuberculosis. Pleural fluid Xpert Ultra (4 studies) Xpert Ultra pooled sensitivity and specificity against culture were 75.0% (58.0 to 86.4) (158 participants; very low-certainty evidence) and 87.0% (63.1 to 97.9) (240 participants; very low-certainty evidence). Of 1000 people where 100 have pleural tuberculosis, 192 would be Xpert Ultra-positive: of these, 117 (61%) would not have tuberculosis; and 808 would be Xpert Ultra-negative: of these, 25 (3%) would have tuberculosis. Xpert MTB/RIF (25 studies) Xpert MTB/RIF pooled sensitivity and specificity against culture were 49.5% (39.8 to 59.9) (644 participants; low-certainty evidence) and 98.9% (97.6 to 99.7) (2421 participants; high-certainty evidence). Of 1000 people where 100 have pleural tuberculosis, 60 would be Xpert MTB/RIF-positive: of these, 10 (17%) would not have tuberculosis; and 940 would be Xpert MTB/RIF-negative: of these, 50 (5%) would have tuberculosis. Lymph node aspirate Xpert Ultra (1 study) Xpert Ultra sensitivity and specificity (95% confidence interval) against composite reference standard were 70% (51 to 85) (30 participants; very low-certainty evidence) and 100% (92 to 100) (43 participants; low-certainty evidence). Of 1000 people where 100 have lymph node tuberculosis, 70 would be Xpert Ultra-positive and 0 (0%) would not have tuberculosis; 930 would be Xpert Ultra-negative and 30 (3%) would have tuberculosis. Xpert MTB/RIF (4 studies) Xpert MTB/RIF pooled sensitivity and specificity against composite reference standard were 81.6% (61.9 to 93.3) (377 participants; low-certainty evidence) and 96.4% (91.3 to 98.6) (302 participants; low-certainty evidence). Of 1000 people where 100 have lymph node tuberculosis, 118 would be Xpert MTB/RIF-positive and 37 (31%) would not have tuberculosis; 882 would be Xpert MTB/RIF-negative and 19 (2%) would have tuberculosis. In lymph node aspirate, Xpert MTB/RIF pooled specificity against culture was 86.2% (78.0 to 92.3), lower than that against a composite reference standard. Using the latent class model, Xpert MTB/RIF pooled specificity was 99.5% (99.1 to 99.7), similar to that observed with a composite reference standard. Rifampicin resistance Xpert Ultra (4 studies) Xpert Ultra pooled sensitivity and specificity were 100.0% (95.1 to 100.0), (24 participants; low-certainty evidence) and 100.0% (99.0 to 100.0) (105 participants; moderate-certainty evidence). Of 1000 people where 100 have rifampicin resistance, 100 would be Xpert Ultra-positive (resistant): of these, zero (0%) would not have rifampicin resistance; and 900 would be Xpert Ultra-negative (susceptible): of these, zero (0%) would have rifampicin resistance. Xpert MTB/RIF (19 studies) Xpert MTB/RIF pooled sensitivity and specificity were 96.5% (91.9 to 98.8) (148 participants; high-certainty evidence) and 99.1% (98.0 to 99.7) (822 participants; high-certainty evidence). Of 1000 people where 100 have rifampicin resistance, 105 would be Xpert MTB/RIF-positive (resistant): of these, 8 (8%) would not have rifampicin resistance; and 895 would be Xpert MTB/RIF-negative (susceptible): of these, 3 (0.3%) would have rifampicin resistance., Authors' Conclusions: Xpert Ultra and Xpert MTB/RIF may be helpful in diagnosing extrapulmonary tuberculosis. Sensitivity varies across different extrapulmonary specimens: while for most specimens specificity is high, the tests rarely yield a positive result for people without tuberculosis. For tuberculous meningitis, Xpert Ultra had higher sensitivity and lower specificity than Xpert MTB/RIF against culture. Xpert Ultra and Xpert MTB/RIF had similar sensitivity and specificity for rifampicin resistance. Future research should acknowledge the concern associated with culture as a reference standard in paucibacillary specimens and consider ways to address this limitation., (Copyright © 2021 The Authors. Cochrane Database of Systematic Reviews published by John Wiley & Sons, Ltd. on behalf of The Cochrane Collaboration.)

Background: We evaluated the performance of pyrosequencing, a genotypic test which detects TB and XDR-defining mutations within 6 h, directly on CSF samples for diagnosing TB meningitis(TBM)., Methods: This retrospective, diagnostic accuracy study was conducted in Hinduja hospital, Mumbai from May-2017 to May-2019. 107 consecutive patients with physician-suspected TBM for whom CSF pyrosequencing was requested were screened. Seven patients with incomplete data were excluded. Diagnostic accuracy of pyrosequencing was compared with Xpert MTB/Rif and TBMGIT (TB Mycobacterial Growth Indicator Tube) culture against the uniform case definition of definite or probable TBM. Susceptibility concordance rate of pyrosequencing with TBMGIT culture and Xpert MTB/Rif was determined., Results: The study cohort comprised of 100 patients[Definite(n = 33), Probable(n = 20), Possible(n = 30), Alternative(n = 17)] with 50% males[median age(years):38(Range:2-87)]. Against the uniform case definition, pyrosequencing had 98·11%(95%CI 89·93-99·95; n = 52/53) sensitivity and 97·79%(86·31-99·67; n = 44/45) negative predictive value(NPV) compared with 43.39%(29·83-57·72; n = 23/53,p < 0.0001) sensitivity and 61.04%(55·31-66·48; n = 47/77) NPV for Xpert MTB/Rif and 45·28%(31·56-59·55; n = 24/53,p < 0.0001) sensitivity and 61·84%(55·92-67·43; n = 47/76) NPV for TBMGIT culture. Susceptibility concordance rate of pyrosequencing with phenotypic Drug Susceptibility Testing was 91.3%(n = 21/23) and with Xpert MTB/Rif was 95·45%(n = 21/22)., Conclusion: CSF pyrosequencing is significantly more sensitive than Xpert MTB/Rif and TBMGIT culture for diagnosing TBM. Additionally, it facilitates early therapeutic decision-making by providing information on XDR-defining mutations., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Tubercular meningitis (TBM) is a serious form of tuberculosis (TB). The diagnosis of TBM & susceptibility/resistance is difficult as TB MGIT culture lacks sensitivity & timeliness. Timely and accurate diagnosis of the TBM is the need of the hour for initiation of appropriate therapy. We have exploited pyrosequencing to detect TB and associated Multi/extensively drug resistant (MDR/ XDR-TB) directly from Cerebrospinal Fluid (CSF) specimens., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Tuberculous meningitis (TBM) is a condition that is caused by Mycobacterium tuberculosis complex and is difficult to diagnose due to the nonspecificity of the presentations. The study analyzed the different modes of diagnosis available in a developing country set up over a period of five years to understand the diagnostic values of the current conventional and automated methods of diagnosis of TBM among the patients suspected with chronic meningitis., Methods: A total of 10,281 cerebrospinal fluid samples (CSF) were collected from suspected chronic meningitis patients, of which 790 samples were from individuals who had clinically suspected TBM. The samples were subjected to CSF cytology and staining, culturing, immunological tests, molecular techniques, and methods for detection of drug resistance., Results: The TBM patients were predominantly male, with a mean age of 21-40 years. CSF pleocytosis and lymphocytic predominance were noted. Culture had 40.13% positivity among clinically suspected TBM patients. The multidrug-resistant M. tuberculosis (MDR-TB) constituted 3.14% of the total clinical isolates. With IS6110 PCR, a specificity of 92.86% and sensitivity of 100% are seen with an assay threshold of 30pg/ml. Line probe assay (LPA) using culture isolates had a sensitivity of 97.67% and a specificity of 100%. Direct CSF LPA showed a sensitivity of 96.15% and a specificity of 100%., Conclusions: A combination of techniques that involved culture, cytology, and DNA amplification methods was found to be promising in specific, accurate, and rapid detection of M. tuberculosis in the CSF samples from patients., (Copyright © 2017. Published by Elsevier B.V.)

The lack of an accurate, rapid diagnostic test for mycobacterium tuberculosis (TB) is a major handicap in the management of spinal TB. GeneXpert, a new, rapid molecular diagnostic test is recommended as the first line investigation for suspected pulmonary TB in areas with a high prevalence of HIV or drug resistance, yet it has not been validated for the diagnosis of musculoskeletal TB. The aim of this study was to assess the accuracy of GeneXpert in diagnosing spinal TB. A prospective clinical study of 69 consecutive adults with suspected spinal TB was conducted at a tertiary hospital in an area with the highest incidence and prevalence of TB in the world. GeneXpert was used on tissue samples of the enrolled patients and its diagnostic accuracy compared with a reference standard of tissue in liquid culture. A total of 71 spine samples from 69 patients (two re-biopsies) were included in the study. The GeneXpert test showed a sensitivity of 95.6% and specificity of 96.2% for spinal TB. The results of the GeneXpert test were available within 48 hours compared with a median of 35 days (IQR 15 to 43) for cultures. All cases of multi-drug resistant TB (MDR TB) were diagnosed accurately with the GeneXpert test. The MDR TB rate was 5.8%., (©2014 The British Editorial Society of Bone & Joint Surgery.)

Drug-resistant tuberculosis, including drug-resistant tuberculous meningitis, is an emerging health problem in many countries. An association with Beijing strains and drug resistance-related mutations, such as mutations in katG and rpoB genes, has been found. The pathology, clinical features and neuroimaging characteristics of drug-resistant tuberculous meningitis are similar to drug-responsive tuberculous meningitis. Detection of mycobacteria in cerebrospinal fluid (CSF) by conventional methods (smear examination or culture) is often difficult. Nucleic acid amplification assays are better methods owing to their rapidity and high sensitivity. The Xpert MTB/RIF assay (Cepheid, CA, USA) is a fully-automated test that has also been found to be effective for CSF samples. Treatment of multidrug-resistant tuberculous meningitis depends on the drug susceptibility pattern of the isolate and/or the previous treatment history of the patient. Second-line drugs with good penetration of the CSF should be preferred. Isoniazid monoresistant disease requires addition of another drug with better CSF penetration. Drug-resistant tuberculous meningitis is associated with a high mortality. HIV infected patients with drug-resistant tuberculous meningitis have severe clinical manifestations with exceptionally high mortality. Prevention of tuberculosis is the key to reduce drug-resistant tuberculous meningitis.

Children are among the subjects most frequently affected by tuberculous meningitis (TBM) due to their relative inability to contain primary Mycobacterium tuberculosis infection in the lung. TBM is a devastating disease with about 30% mortality among the most severe cases; moreover, 50% of survivors have neurological sequelae despite an apparently adequate administration of antibiotics. Early diagnosis and prompt treatment are crucial for reducing the risk of a poor outcome. However, especially in children, the best and most rapid way to confirm the diagnosis is controversial; the optimal choice, dose, and treatment duration of anti-tuberculosis drugs are not precisely defined, and the actual importance of adjunctive therapies with steroids and neurosurgery has not been adequately demonstrated. This review is an effort to discuss present knowledge of the diagnosis and treatment of pediatric TBM in order to offer the best solution to address this dramatic disease. In conclusion, we stress that new studies in children are urgently needed because data in the early years of life are more debatable than those collected in adults. In the meantime, when treating a child with suspected TBM, the most aggressive attitude to diagnosis and therapy is necessary, because TBM is a devastating disease., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Drug-resistant tuberculosis is an increasing problem worldwide. There are few reports of drug susceptibility patterns of Mycobacterium tuberculosis isolated from cases of tuberculous meningitis. A 5-year retrospective study aimed at analysing the drug susceptibility profile of M. tuberculosis isolated from tuberculous meningitis cases was conducted. A total of 366 isolates were analysed. Among these, 301 (82.2%) were sensitive to all the four primary drugs tested, while 65 (17.8%) showed resistance. There were 46 (12.5%) isolates resistant to isoniazid (INH), while 9 (2.4%) demonstrated multidrug resistance. These data suggest that multidrug resistance in tuberculous meningitis is not yet a serious problem. However, a periodic review is required to ascertain the global incidence of drug-resistant tuberculous meningitis.