Establishing the cascade of care for patients with tuberculous meningitis

Advancing the chemotherapy of tuberculous meningitis: a consensus view

Tuberculous meningitis causes death or disability in approximately 50% of affected individuals and kills approximately 78 200 adults every year. Antimicrobial treatment is based on regimens used for pulmonary tuberculosis, which overlooks important differences between lung and brain drug distributions. Tuberculous meningitis has a profound inflammatory component, yet only adjunctive corticosteroids have shown clear benefit. There is an active pipeline of new antitubercular drugs, and the advent of biological agents targeted at specific inflammatory pathways promises a new era of improved tuberculous meningitis treatment and outcomes. Yet, to date, tuberculous meningitis trials have been small, underpowered, heterogeneous, poorly generalisable, and have had little effect on policy and practice. Progress is slow, and a new approach is required. In this Personal View, a global consortium of tuberculous meningitis researchers articulate a coordinated, definitive way ahead via globally conducted clinical trials of novel drugs and regimens to advance treatment and improve outcomes for this life-threatening infection.

A qualitative study of factors resulting in care delays for adults with meningitis in Zambia

BACKGROUND

Meningitis causes significant mortality in regions with high comorbid HIV and TB. Improved outcomes are hindered by limited understanding of factors that delay adequate care.

METHODS

In-depth interviews of patients admitted to the University Teaching Hospital with suspected meningitis, their caregivers, doctors and nurses were conducted. Patient/caregiver interviews explored meningitis understanding, treatment prior to admission and experiences since admission. Provider interviews addressed current and prior experiences with meningitis patients and hospital barriers to care. A conceptual framework based on the Three Delays Model identified factors that delayed care.

RESULTS

Twenty-six patient/caregiver, eight doctor and eight nurse interviews occurred. Four delays were identified: in-home care; transportation to a health facility; clinic/first-level hospital care; and third-level hospital. Overcrowding and costly diagnostic testing delayed outpatient care; 23% of patients began with treatment inside the home due to prior negative experiences with biomedical care. Admission occurred after multiple clinic visits, where subsequent delays occurred during testing and treatment.

CONCLUSIONS

Delays in care from home to hospital impair quality meningitis care in Zambia. Interventions to improve outcomes must address patient, community and health systems factors. Patient/caregiver education regarding signs of meningitis and indications for care-seeking are warranted to reduce treatment delays.

CSF Metabolomics of Tuberculous Meningitis: A Review

From the World Health Organization's global TB report for 2020, it is estimated that in 2019 at least 80,000 children (a particularly vulnerable population) developed tuberculous meningitis (TBM)-an invariably fatal disease if untreated-although this is likely an underestimate. As our latest technologies have evolved-with the unprecedented development of the various "omics" disciplines-a mountain of new data on infectious diseases have been created. However, our knowledge and understanding of infectious diseases are still trying to keep pace. Metabolites offer much biological information, but the insights they permit can be difficult to derive. This review summarizes current metabolomics studies on cerebrospinal fluid (CSF) from TBM cases and collates the metabolic data reported. Collectively, CSF metabolomics studies have identified five classes of metabolites that characterize TBM: amino acids, organic acids, nucleotides, carbohydrates, and "other". Taken holistically, the information given in this review serves to promote the mechanistic action of hypothesis generation that will drive and direct future studies on TBM.

The global burden of tuberculous meningitis in adults: A modelling study

Tuberculous meningitis (TBM) is the most lethal form of tuberculosis. The incidence and mortality of TBM is unknown due to diagnostic challenges and limited disaggregated reporting of treated TBM by existing surveillance systems. We aimed to estimate the incidence and mortality of TBM in adults (15+ years) globally. Using national surveillance data from Brazil, South Africa, the United Kingdom, the United States of America, and Vietnam, we estimated the fraction of reported tuberculosis that is TBM, and the case fatality ratios for treated TBM in each of these countries. We adjusted these estimates according to findings from a systematic review and meta-analysis and applied them to World Health Organization tuberculosis notifications and estimates to model the global TBM incidence and mortality. Assuming the case detection ratio (CDR) for TBM was the same as all TB, we estimated that in 2019, 164,000 (95% UI; 129,000-199,000) adults developed TBM globally; 23% were among people living with HIV. Almost 60% of incident TBM occurred in males and 20% were in adults 25-34 years old. 70% of global TBM incidence occurred in Southeast Asia and Africa. We estimated that 78,200 (95% UI; 52,300-104,000) adults died of TBM in 2019, representing 48% of incident TBM. TBM case fatality in those treated was on average 27%. Sensitivity analysis assuming improved detection of TBM compared to other forms of TB (CDR odds ratio of 2) reduced estimated global mortality to 54,900 (95% UI; 32,200-77,700); assuming instead worse detection for TBM (CDR odds ratio of 0.5) increased estimated mortality to 125,000 (95% UI; 88,800-161,000). Our results highlight the need for improved routine TBM monitoring, especially in high burden countries. Reducing TBM incidence and mortality will be necessary to achieve the End TB Strategy targets.

Knowledge gaps and research priorities in tuberculous meningitis

Tuberculous meningitis (TBM) is the most severe and disabling form of tuberculosis (TB), accounting for around 1-5% of the global TB caseload, with mortality of approximately 20% in children and up to 60% in persons co-infected with human immunodeficiency virus even in those treated. Relatively few centres of excellence in TBM research exist and the field would therefore benefit from greater co-ordination, advocacy, collaboration and early data sharing. To this end, in 2009, 2015 and 2019 we convened the TBM International Research Consortium, bringing together approximately 50 researchers from five continents. The most recent meeting took place on 1 st and 2 nd March 2019 in Lucknow, India. During the meeting, researchers and clinicians presented updates in their areas of expertise, and additionally presented on the knowledge gaps and research priorities in that field. Discussion during the meeting was followed by the development, by a core writing group, of a synthesis of knowledge gaps and research priorities within seven domains, namely epidemiology, pathogenesis, diagnosis, antimicrobial therapy, host-directed therapy, critical care and implementation science. These were circulated to the whole consortium for written input and feedback. Further cycles of discussion between the writing group took place to arrive at a consensus series of priorities. This article summarises the consensus reached by the consortium concerning the unmet needs and priorities for future research for this neglected and often fatal disease.