Toxoplasma gondii infection in the central nervous system commonly occurs among immunodeficient patients. Its prevalence is high in countries with a high burden of HIV and low coverage of antiretroviral drugs. The brain is one of the predilections for T. gondii infection due to its low inflammatory reaction, and cerebral toxoplasmosis occurs solely due to the reactivation of a latent infection rather than a new infection. Several immune elements have recently been recognized to have an essential role in the immunopathogenesis of cerebral toxoplasmosis. Although real-time isothermal amplification, next-generation sequencing, and enzyme-linked aptamer assays from blood samples have been the recommended diagnostic tools in some in-vivo studies, a combination of clinical symptoms, serology examination, and neuroimaging are still the daily standard for the presumptive diagnosis of cerebral toxoplasmosis and early anti-toxoplasma administration. Clinical trials are needed to find a new therapy that is less likely to affect folate synthesis, have neuroprotective properties, or cure the latent phase of infection. The development of a vaccine is being extensively tested in animals, but its efficacy and safety for humans are still not proven.

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. 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. 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). 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.

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. 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. 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. 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.

High doses of rifampicin may help tuberculous meningitis (TBM) patients to survive. Pharmacokinetic-pharmacodynamic evaluations suggested that rifampicin doses higher than 13 mg/kg intravenously or 20 mg/kg orally (as previously studied) are warranted to maximize treatment response. In a double-blinded, randomised, placebo-controlled phase II trial, we assigned 60 adult TBM patients in Bandung, Indonesia, to standard 450 mg, 900 mg or 1350 mg (10, 20 and 30 mg/kg) oral rifampicin combined with other TB drugs for 30 days. Endpoints included pharmacokinetic measures, adverse events and survival. A double and triple dose of oral rifampicin led to three and five-fold higher geometric mean total exposures in plasma in the critical early days (2±1) of treatment (AUC_0-24h: 53·5 mg.h/L vs 170·6 mg.h/L vs. 293·5 mg.h/L, p<0·001), with proportional increases in CSF concentrations and without an increase in the incidence of grade 3/4 adverse events. Six-month mortality was 7/20 (35%), 9/20 (45%) and 3/20 (15%) in the 10, 20 and 30 mg/kg groups, respectively (p=0·12). Tripling the standard dose caused a large increase in rifampicin exposure in plasma and CSF and was safe. Survival benefit with this dose should now be evaluated in a larger phase III clinical trial.