Improving the microbiological diagnosis of tuberculous meningitis: A prospective, international, multicentre comparison of conventional and modified Ziehl-Neelsen stain, GeneXpert, and culture of cerebrospinal fluid.

OBJECTIVES: Tuberculous meningitis (TBM) is the severest form of tuberculosis, but current diagnostic tests are insensitive. Recent reports suggest simple modifications to conventional cerebrospinal fluid (CSF) Ziehl-Neelsen (ZN) staining may greatly improve sensitivity. We sought to define the performance of modified and conventional ZN stain for TBM diagnosis. METHODS: In hospitals in Vietnam, South Africa and Indonesia we conducted a prospective study of modified ZN with or without cytospin, conventional ZN smear, GeneXpert, and culture on CSF in adults with suspected TBM. RESULTS: A total of 618 individuals were enrolled across 3 sites. Compared with the TBM clinical diagnostic gold standard for research (definite probable or possible TBM), sensitivity of conventional ZN and modified ZN with cytospin were 33.9% and 34.5% respectively (p = 1.0 for the difference between tests), compared with culture 31.8% and Xpert 25.1%. Using culture as a reference, sensitivities of conventional ZN, modified ZN with cytospin, and Xpert were 66.4%, 67.5%, and 72.3%, respectively. Higher CSF volume and lactate, and lower CSF:blood glucose ratio were independently associated with microbiologically confirmed TBM. CONCLUSIONS: Modified ZN stain does not improve diagnosis of TBM. Currently available tests are insensitive, but testing large CSF volumes improves performance. New diagnostic tests for TBM are urgently required.

Microbiological diagnosis of adult tuberculous meningitis in a ten-year cohort in Indonesia.

We evaluated microbiological diagnosis of tuberculous (TB) meningitis in a referral hospital in Indonesia. Over a ten-year period, we examined cerebrospinal fluid (CSF) samples of 1180 adult meningitis suspects. Sensitivity of different methods was compared, and results were stratified for HIV status, disease severity, and CSF volume. TB meningitis was bacteriologically confirmed in 501 patients. Using clinical diagnosis as reference standard (n = 713), sensitivity of different methods was 12.2% (86/703) for microscopy, 42% (73/174) for Xpert MTB/RIF, 46.0% (163/354) for solid culture, 48.8% (332/680) for liquid culture, and 64.0% (212/331) for in-house PCR. Head to head comparisons in 654 patients showed a higher yield of in-house PCR (32.3%) compared to culture (15.6%, P < 0.01). Microscopic observation of drug susceptibility (MODS) culture more rapidly became positive compared to other culture methods. Yield of culture was lower in HIV-infected (39/105) than in HIV-negative patients (N = 316/585; P < 0.01). Molecular and culture methods gave higher yields in patients with more severe disease (P < 0.01). CSF volume of ≥6 ml increased the yield of culture (42.8% versus 12.1% for CSF <6 ml, P < 0.01) and ZN-microscopy (18.3% versus 1.9% for CSF <6 ml, P < 0.01). CSF centrifugation had no clear effect on sensitivity of Xpert MTB/RIF. ZN-microscopy lacks sensitivity for diagnosis of TB meningitis. For molecular assays, in-house IS6110-PCR is more sensitive than Xpert MTB/RIF. MODS culture has a clear advantage in terms of speed. Large CSF volumes are necessary for all tests. The effect of CSF processing for Xpert MTB/RIF needs further study.

Cerebral tryptophan metabolism and outcome of tuberculous meningitis: an observational cohort study.

BACKGROUND: Immunopathology contributes to the high mortality of tuberculous meningitis, but the biological pathways involved are mostly unknown. We aimed to compare cerebrospinal fluid (CSF) and serum metabolomes of patients with tuberculous meningitis with that of controls without tuberculous meningitis, and assess the link between metabolite concentrations and mortality. METHODS: In this observational cohort study at the Hasan Sadikin Hospital (Bandung, Indonesia) we measured 425 metabolites using liquid chromatography-mass spectrometry in CSF and serum from 33 HIV-negative Indonesian patients with confirmed or probable tuberculous meningitis and 22 control participants with complete clinical data between March 12, 2009, and Oct 27, 2013. Associations of metabolite concentrations with survival were validated in a second cohort of 101 patients from the same centre. Genome-wide single nucleotide polymorphism typing was used to identify tryptophan quantitative trait loci, which were used for survival analysis in a third cohort of 285 patients. FINDINGS: Concentrations of 250 (70%) of 351 metabolites detected in CSF were higher in patients with tuberculous meningitis than in controls, especially in those who died during follow-up. Only five (1%) of the 390 metobolites detected in serum differed between patients with tuberculous meningitis and controls. CSF tryptophan concentrations showed a pattern different from most other CSF metabolites; concentrations were lower in patients who survived compared with patients who died (9-times) and to controls (31-times). The association of low CSF tryptophan with patient survival was confirmed in the validation cohort (hazard ratio 0·73; 95% CI 0·64-0·83; p<0·0001; per each halving). 11 genetic loci predictive for CSF tryptophan concentrations in tuberculous meningitis were identified (p<0·00001). These quantitative trait loci predicted survival in a third cohort of 285 HIV-negative patients in a prognostic index including age and sex, also after correction for possible confounders (p=0·0083). INTERPRETATION: Cerebral tryptophan metabolism, which is known to affect Mycobacterium tuberculosis growth and CNS inflammation, is important for the outcome of tuberculous meningitis. CSF tryptophan concentrations in tuberculous meningitis are under strong genetic influence, probably contributing to the variable outcomes of tuberculous meningitis. Interventions targeting tryptophan metabolism could improve outcomes of tuberculous meningitis. FUNDING: Royal Dutch Academy of Arts and Sciences; Netherlands Foundation for Scientific Research; Radboud University; National Academy of Sciences; Ministry of Research, Technology, and Higher Education, Indonesia; European Research Council; and PEER-Health.

Clinical Parameters, Routine Inflammatory Markers, and LTA4H Genotype as Predictors of Mortality Among 608 Patients With Tuberculous Meningitis in Indonesia.

Background: Damaging inflammation is thought to contribute to the high morbidity and mortality of tuberculous meningitis (TBM), but the link between inflammation and outcome remains unclear. Methods: We performed prospective clinical and routine laboratory analyses of a cohort of adult patients with TBM in Indonesia. We also examined the LTA4H promoter polymorphism, which predicted cerebrospinal fluid (CSF) leukocyte count and survival of Vietnamese patients with TBM. Patients were followed for >1 year. Results: We included 608 patients with TBM, of whom 67.1% had bacteriological confirmation of disease and 88.2% had severe (ie, grade II or III) disease. One-year mortality was 43.7% and strongly associated with decreased consciousness, fever, and focal neurological signs. Human immunodeficiency virus (HIV) infection, present in 15.3% of patients, was associated with higher mortality and different CSF characteristics, compared with absence of HIV infection. Among HIV-uninfected patients, mortality was associated with higher CSF neutrophil counts (hazard ratio [HR], 1.10 per 10% increase; 95% confidence interval [CI], 1.04-1.16), low CSF to blood glucose ratio (HR, 1.16 per 0.10 decrease; 95% CI, 1.04-1.30), CSF culture positivity (HR, 1.37; 95% CI, 1.02-1.84), and blood neutrophilia (HR, 1.06 per 109 neutrophils/L increase; 95% CI, 1.03-1.10). The LTA4H promoter polymorphism correlated with CSF mononuclear cell count but not with mortality (P = .915). Conclusions: A strong neutrophil response and fever may contribute to or be a result of (immuno)pathology in TBM. Aggressive fever control might improve outcome, and more-precise characterization of CSF leukocytes could guide possible host-directed therapeutic strategies in TBM.

Predominance of modern Mycobacterium tuberculosis strains and active transmission of Beijing sublineage in Jayapura, Indonesia Papua.

Mycobacterium tuberculosis genotype distribution is different between West and Central Indonesia, but there are no data on the most Eastern part, Papua. We aimed to identify the predominant genotypes of M. tuberculosis responsible for tuberculosis in coastal Papua, their transmission, and the association with patient characteristics. A total of 199 M. tuberculosis isolates were collected. Spoligotyping was applied to describe the population structure of M. tuberculosis, lineage identification was performed using a combination of lineage-specific markers, and genotypic clusters were identified using a combination of 24-locus-MIRU-VNTR and spoligotyping. A high degree of genetic diversity was observed among isolates based on their spoligopatterns. Strains from modern lineage 4 made up almost half of strains (46.9%), being more abundant than the ancient lineage 1 (33.7%), and modern lineage 2 (19.4%). Thirty-five percent of strains belonged to genotypic clusters, especially strains in the Beijing genotype. Previous TB treatment and mutations associated with drug resistance were more common in patients infected with strains of the Beijing genotype. Papua shows a different distribution of M. tuberculosis genotypes compared to other parts of Indonesia. Clustering and drug resistance of modern strains recently introduced to Papua may contribute to the high tuberculosis burden in this region.

Implementation of LED fluorescence microscopy for diagnosis of pulmonary and HIV-associated tuberculosis in a hospital setting in Indonesia.

BACKGROUND: Fluorescence microscopy (FM) has not been implemented widely in TB endemic settings and little evaluation has been done in HIV-infected patients. We evaluated diagnostic performance, time and costs of FM with light-emitting diodes technology (LED-FM), compared with conventional (Zieh-Neelsen) microscopy in a hospital in Indonesia which acts as referral centre for HIV-infected patients. METHOD: We included pulmonary tuberculosis suspects from the outpatient and HIV clinic. Direct and concentrated sputum smears were examined using LED-FM and ZN microscopy by two technicians who were blinded for the HIV-status and the result of the comparative test. Mean reading time per slide was recorded and cost of each slide was calculated. Mycobacteria culture served as the reference standard. RESULTS: Among 404 tuberculosis suspects from the outpatient clinic and 256 from the HIV clinic, mycobacteria culture was positive in 12.6% and 27%, respectively. The optimal sensitivity of LED-FM was achieved by using a threshold of ≥2 AFB/length. LED-FM had a higher sensitivity (75.5% vs. 54.9%, P<0.01) but lower specificity (90.0% vs 96.6%, P<0.01) compared to ZN microscopy. HIV was associated with a lower sensitivity but similar specificity. The average reading time using LED-FM was significantly shorter (2.23±0.78 vs 5.82±1.60 minutes, P<0.01), while costs per slide were similar. CONCLUSION: High sensitivity of LED-FM combined with shorter reading time of sputum smear slides make this method a potential alternative to ZN microscopy. Additional data on specificity are needed for effective implementation of this technique in high burden TB laboratories.