A Comparison of Recruitment Methods for a Remote, Nationwide Clinical Trial for COVID-19 Treatment.

This study describes decentralized recruitment and enrollment for a COVID-19 treatment trial, while comparing 5 primary recruitment methods: search engine ads, paid advertising within a national testing company, paid advertising within a regional testing company, electronic health record messages, and word of mouth. These are compared across patient demographics, efficiency, and cost. Clinical Trials Registration: NCT04510194.

Diagnostic Prediction Model for Tuberculous Meningitis: An Individual Participant Data Meta-Analysis.

No accurate and rapid diagnostic test exists for tuberculous meningitis (TBM), leading to delayed diagnosis. We leveraged data from multiple studies to improve the predictive performance of diagnostic models across different populations, settings, and subgroups to develop a new predictive tool for TBM diagnosis. We conducted a systematic review to analyze eligible datasets with individual-level participant data (IPD). We imputed missing data and explored three approaches: stepwise logistic regression, classification and regression tree (CART), and random forest regression. We evaluated performance using calibration plots and C-statistics via internal-external cross-validation. We included 3,761 individual participants from 14 studies and nine countries. A total of 1,240 (33%) participants had "definite" (30%) or "probable" (3%) TBM by case definition. Important predictive variables included cerebrospinal fluid (CSF) glucose, blood glucose, CSF white cell count, CSF differential, cryptococcal antigen, HIV status, and fever presence. Internal validation showed that performance varied considerably between IPD datasets with C-statistic values between 0.60 and 0.89. In external validation, CART performed the worst (C = 0.82), and logistic regression and random forest had the same accuracy (C = 0.91). We developed a mobile app for TBM clinical prediction that accounted for heterogeneity and improved diagnostic performance (https://tbmcalc.github.io/tbmcalc). Further external validation is needed.

Infectious Diseases Physician Management of Cryptococcal Meningitis in North America-Is Single High-Dose Liposomal Amphotericin B Being Used?

Background: Several recent randomized trials have been conducted in resource-limited settings for cryptococcal meningitis that have rapidly innovated international guidelines. The 2010 Infectious Diseases Society of America (IDSA) cryptococcal meningitis guideline has not been updated with recent trials. The 2022 AMBITION-cm trial found that a single 10-mg/kg dose of liposomal amphotericin B plus daily flucytosine and fluconazole for 2 weeks was noninferior to 1 week of amphotericin B deoxycholate with flucytosine. It is unknown whether physicians in high-resource settings are using this regimen or more traditional regimens. Methods: We developed an electronic survey in June 2023 to better understand whether physician members of the IDSA Emerging Infections Network (EIN) and Mycoses Study Group Education and Research Consortium (MSG-ERC) had used the AMBITION-cm induction regimen, would use the regimen in hypothetical clinical scenarios, and what perceived barriers to use existed. Results: A total of 242 of 561 (43%) physicians responded to the survey, of whom 205 provided care for persons with cryptococcal meningitis in the last year. Overall, 29 (14%) had used the AMBITION-cm regimen, and 176 (86%) had not. In various hypothetical clinical scenarios, only ∼10% of 209 respondents selected the AMBITION-cm regimen as preferred. Perceived barriers to uptake included the applicability of trials performed in low-resource settings to high-resource settings, that the regimen is not recommended in the 2010 IDSA guidelines, and the applicability to persons without HIV. Conclusions: Most respondents had not used the single-dose liposomal amphotericin B regimen, but the regimen is being used. Further study of this regimen in other patient populations and settings is necessary.

Impact of Cerebrospinal Fluid Leukocyte Infiltration and Neuroimmmune Mediators on Survival with HIV-Associated Cryptococcal Meningitis.

Introduction: Cryptococcal meningitis remains a prominent cause of death in persons with advanced HIV disease. CSF leukocyte infiltration predicts survival at 18 weeks; however, how CSF immune response relates to CSF leukocyte infiltration is unknown. Methods: We enrolled 401 adults with HIV-associated cryptococcal meningitis in Uganda who received amphotericin and fluconazole induction therapy. We assessed the association of CSF leukocytes, chemokine, and cytokine responses with 18-week survival. Results: Participants with CSF leukocytes ≥50/µL, had higher probability 68% (52/77) of 18-week survival compared with 52% (151/292) 18-week survival in those with ≤50 cells/µL (Hazard Ratio=1.63, 95% confidence intervals 1.14-2.23; p=0.008). Survival was also associated with higher expression of T helper (Th)-1, Th17 cytokines, and immune regulatory elements. CSF levels of Programmed Death-1 Ligand, CXCL10, and Interleukin (IL)-2 independently predicted survival. In multivariate analysis, CSF leukocytes were inversely associated with CSF fungal burden and positively associated with CSF protein, interferon-gamma (IFN-γ), IL-17A, tumor necrosis factor (TNF)-α, and peripheral blood CD4+ and CD8+ T cells expression. Conclusion: 18-week survival after diagnosis of cryptococcal meningitis was associated with higher CSF leukocytes at baseline with greater T helper 1 (IFN-γ, IL-2 and TNF-α cytokines), T helper 17 (IL-17A cytokine) and CXCR3+ T cell (CXCL10 chemokine) responses. These results highlight the interdependent contribution of soluble and cellular immune responses in predicting survival with HIV-associated cryptococcal meningitis.

Comparison of early fungicidal activity and mortality between daily liposomal amphotericin B and daily amphotericin B deoxycholate among patients with HIV-associated cryptococcal meningitis.

BACKGROUND: Limited data exist on the antifungal activity of daily liposomal amphotericin B with flucytosine induction regimens for cryptococcal meningitis, which are recommended in high-income countries. Liposomal amphotericin B monotherapy at 3 mg/kg previously failed to meet non-inferiority criteria compared to amphotericin B deoxycholate in its registrational clinical trial. We aimed to compare the quantitative antifungal activity and mortality between daily amphotericin B deoxycholate and daily liposomal amphotericin among persons with HIV-related cryptococcal meningitis receiving adjunctive flucytosine 100 mg/kg/day. METHODS: We analyzed data from three clinical studies involving participants with HIV-associated cryptococcal meningitis receiving either daily liposomal amphotericin B at 3 mg/kg/day with flucytosine (N = 94) or amphotericin B deoxycholate at 0.7-1.0 mg/kg/day with flucytosine (N = 404) as induction therapy. We compared participant baseline characteristics, CSF early fungicidal activity (EFA), and 10-week mortality. RESULTS: We included 498 participants in this analysis, of whom 201 had available EFA data (N = 46 liposomal amphotericin; N = 155 amphotericin deoxycholate). Overall, there is no statistical evidence that the antifungal activity of liposomal amphotericin B (mean EFA = 0.495 log10 CFU/mL/day; 95%CI, 0.355-0.634) differ from amphotericin B deoxycholate (mean EFA = 0.402 log10 CFU/mL; 95%CI, 0.360-0.445) (P = 0.13). Mortality at 10 weeks trended lower for liposomal amphotericin (28.2%) vs amphotericin B deoxycholate (34.6%) but was not statistically different when adjusting for baseline characteristics (adjusted Hazard Ratio = 0.74; 95%CI, 0.44-1.25; P = 0.26). CONCLUSIONS: Daily liposomal amphotericin B induction demonstrated a similar rate of CSF fungal clearance and 10-week mortality as amphotericin B deoxycholate when combined with flucytosine for the treatment of HIV-associated cryptococcal meningitis.

Post-mortem analysis of dolutegravir, tenofovir, lamivudine and efavirenz penetration in multiple CNS compartments.

BACKGROUND: Central nervous system (CNS) compartmentalization provides opportunity for HIV persistence and resistance development. Differences between cerebrospinal fluid (CSF) and cerebral matter regarding HIV persistence are well described. However, CSF is often used as surrogate for CNS drug exposure, and knowledge from solid brain tissue is rare. METHODS: Dolutegravir, tenofovir, lamivudine and efavirenz concentrations were measured across 13 CNS regions plus plasma in samples collected during autopsy in 49 Ugandan decedents. Median time from death to autopsy was 8 (IQR 5,15) hours. To evaluate postmortem redistribution, a time course study was performed in a mouse model. RESULTS: Regions with the highest penetration ratios were choroid plexus/arachnoid (dolutegravir and tenofovir), CSF (lamivudine), and cervical spinal cord/meninges (efavirenz); the lowest were corpus callosum (dolutegravir and tenofovir), frontal lobe (lamivudine), and parietal lobe (efavirenz). On average, brain concentrations were 84%, 87%, and 76% of CSF for dolutegravir, tenofovir, and lamivudine respectively. Postmortem redistribution was observed in the mouse model, with tenofovir and lamivudine concentration increased by 350% and efavirenz concentration decreased by 24% at 24-hours post-mortem. CONCLUSION: Analysis of postmortem tissue provides a unique opportunity to investigate CNS antiretroviral penetration. Regional differences were observed paving the way to identify mechanisms of viral compartmentalization and/or neurotoxicity.

Favorable Antiviral Effect of Metformin on Severe Acute Respiratory Syndrome Coronavirus 2 Viral Load in a Randomized, Placebo-Controlled Clinical Trial of Coronavirus Disease 2019.

BACKGROUND: Metformin has antiviral activity against RNA viruses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The mechanism appears to be suppression of protein translation via targeting the host mechanistic target of rapamycin pathway. In the COVID-OUT randomized trial for outpatient coronavirus disease 2019 (COVID-19), metformin reduced the odds of hospitalizations/death through 28 days by 58%, of emergency department visits/hospitalizations/death through 14 days by 42%, and of long COVID through 10 months by 42%. METHODS: COVID-OUT was a 2 × 3 randomized, placebo-controlled, double-blind trial that assessed metformin, fluvoxamine, and ivermectin; 999 participants self-collected anterior nasal swabs on day 1 (n = 945), day 5 (n = 871), and day 10 (n = 775). Viral load was quantified using reverse-transcription quantitative polymerase chain reaction. RESULTS: The mean SARS-CoV-2 viral load was reduced 3.6-fold with metformin relative to placebo (-0.56 log10 copies/mL; 95% confidence interval [CI], -1.05 to -.06; P = .027). Those who received metformin were less likely to have a detectable viral load than placebo at day 5 or day 10 (odds ratio [OR], 0.72; 95% CI, .55 to .94). Viral rebound, defined as a higher viral load at day 10 than day 5, was less frequent with metformin (3.28%) than placebo (5.95%; OR, 0.68; 95% CI, .36 to 1.29). The metformin effect was consistent across subgroups and increased over time. Neither ivermectin nor fluvoxamine showed effect over placebo. CONCLUSIONS: In this randomized, placebo-controlled trial of outpatient treatment of SARS-CoV-2, metformin significantly reduced SARS-CoV-2 viral load, which may explain the clinical benefits in this trial. Metformin is pleiotropic with other actions that are relevant to COVID-19 pathophysiology. CLINICAL TRIALS REGISTRATION: NCT04510194.

Effect of Montelukast vs Placebo on Time to Sustained Recovery in Outpatients with COVID-19: The ACTIV-6 Randomized Clinical Trial.

Importance: The effect of montelukast in reducing symptom duration among outpatients with mild to moderate coronavirus disease 2019 (COVID-19) is uncertain. Objective: To assess the effectiveness of montelukast compared with placebo in treating outpatients with mild to moderate COVID-19. Design Setting and Participants: The ACTIV-6 platform randomized clinical trial aims to evaluate the effectiveness of repurposed medications in treating mild to moderate COVID-19. Between January 27, 2023, and June 23, 2023, 1250 participants ≥30 years of age with confirmed SARS-CoV-2 infection and ≥2 acute COVID-19 symptoms for ≤7 days, were included across 104 US sites to evaluate the use of montelukast. Interventions: Participants were randomized to receive montelukast 10 mg once daily or matched placebo for 14 days. Main Outcomes and Measures: The primary outcome was time to sustained recovery (defined as at least 3 consecutive days without symptoms). Secondary outcomes included time to death; time to hospitalization or death; a composite of hospitalization, urgent care visit, emergency department visit, or death; COVID clinical progression scale; and difference in mean time unwell. Results: Among participants who were randomized and received study drug, the median age was 53 years (IQR 42-62), 60.2% were female, 64.6% identified as Hispanic/Latino, and 56.3% reported ≥2 doses of a SARS-CoV-2 vaccine. Among 628 participants who received montelukast and 622 who received placebo, differences in time to sustained recovery were not observed (adjusted hazard ratio [HR] 1.02; 95% credible interval [CrI] 0.92-1.12; P(efficacy) = 0.63]). Unadjusted median time to sustained recovery was 10 days (95% confidence interval 10-11) in both groups. No deaths were reported and 2 hospitalizations were reported in each group; 36 participants reported healthcare utilization events (a priori defined as death, hospitalization, emergency department/urgent care visit); 18 in the montelukast group compared with 18 in the placebo group (HR 1.01; 95% CrI 0.45-1.84; P(efficacy)=0.48). Five participants experienced serious adverse events (3 with montelukast and 2 with placebo). Conclusions and Relevance: Among outpatients with mild to moderate COVID-19, treatment with montelukast does not reduce duration of COVID-19 symptoms. Trial Registration: ClinicalTrials.gov ( NCT04885530 ).

Complex Decisions in HIV-Related Cryptococcosis: Addressing Second Episodes of Cryptococcal Meningitis.

PURPOSE OF REVIEW: This review highlights the difficulties in diagnosing and treating persons with a prior history of cryptococcal meningitis who improve but suffer from a recurrence of symptoms. This scenario is well known to those who frequently care for patients with cryptococcal meningitis but is not well understood. We highlight major gaps in knowledge. RECENT FINDINGS: We recently summarized our experience with 28 persons with paradoxical immune reconstitution inflammatory syndrome (IRIS) and 81 persons with microbiological relapse. CD4 count and cerebrospinal fluid white blood cell count were higher in IRIS than relapse but neither was reliable enough to routinely differentiate these conditions. Second-episode cryptococcal meningitis remains a difficult clinical scenario as cryptococcal antigen, while excellent for initial diagnosis has no value in differentiating relapse of infection from other causes of recurrent symptoms. Updated research definitions are proposed and rapid, accurate diagnostic tests are urgently needed.

Global guideline for the diagnosis and management of cryptococcosis: an initiative of the ECMM and ISHAM in cooperation with the ASM.

Cryptococcosis is a major worldwide disseminated invasive fungal infection. Cryptococcosis, particularly in its most lethal manifestation of cryptococcal meningitis, accounts for substantial mortality and morbidity. The breadth of the clinical cryptococcosis syndromes, the different patient types at-risk and affected, and the vastly disparate resource settings where clinicians practice pose a complex array of challenges. Expert contributors from diverse regions of the world have collated data, reviewed the evidence, and provided insightful guideline recommendations for health practitioners across the globe. This guideline offers updated practical guidance and implementable recommendations on the clinical approaches, screening, diagnosis, management, and follow-up care of a patient with cryptococcosis and serves as a comprehensive synthesis of current evidence on cryptococcosis. This Review seeks to facilitate optimal clinical decision making on cryptococcosis and addresses the myriad of clinical complications by incorporating data from historical and contemporary clinical trials. This guideline is grounded on a set of core management principles, while acknowledging the practical challenges of antifungal access and resource limitations faced by many clinicians and patients. More than 70 societies internationally have endorsed the content, structure, evidence, recommendation, and pragmatic wisdom of this global cryptococcosis guideline to inform clinicians about the past, present, and future of care for a patient with cryptococcosis.

Divergent neuroimmune signatures in the cerebrospinal fluid predict differential gender-specific survival among patients with HIV-associated cryptococcal meningitis.

Introduction: Survival among people with HIV-associated cryptococcal meningitis (CM) remains low, particularly among women, despite the currently optimal use of antifungal drugs. Cryptococcus dissemination into the central nervous system [brain, spinal cord, and cerebrospinal fluid (CSF)] elicits the local production of cytokines, chemokines, and other biomarkers. However, no consistent diagnostic or prognostic neuroimmune signature is reported to underpin the risk of death or to identify mechanisms to improve treatment and survival. We hypothesized that distinct neuroimmune signatures in the CSF would distinguish survivors from people who died on antifungal treatment and who may benefit from tailored therapy. Methods: We considered baseline clinical features, CSF cryptococcal fungal burden, and CSF neuroimmune signatures with survival at 18 weeks among 419 consenting adults by "gender" (168 women and 251 men by biological sex defined at birth). Results: Survival at 18 weeks was significantly lower among women than among men {47% vs. 59%, respectively; hazard ratio (HR) = 1.4 [95% confidence interval (CI), 1.0 to 1.9; p = 0.023]}. Unsupervised principal component analysis (PCA) demonstrated divergent neuroimmune signatures by gender, survival, and intragender-specific survival. Overall, women had lower levels of programmed death ligand 1, Interleukin (IL) (IL-11RA/IL-1F30, and IL-15 (IL-15) than men (all p < 0.028). Female survivors compared with those who died expressed significant elevations in levels of CCL11 and CXCL10 chemokines (both p = 0.001), as well as increased T helper 1, regulatory, and T helper 17 cytokines (all p < 0.041). In contrast, male survivors expressed lower levels of IL-15 and IL-8 compared with men who died (p < 0.044). Conclusions: Survivors of both genders demonstrated a significant increase in the levels of immune regulatory IL-10. In conclusion, the lower survival among women with CM was accompanied by distinct differential gender-specific neuroimmune signatures. These female and male intragender-specific survival-associated neuroimmune signatures provide potential targets for interventions to advance therapy to improve the low survival among people with HIV-associated CM.

5-Flucytosine Longitudinal Antifungal Susceptibility Testing of Cryptococcus neoformans: A Substudy of the EnACT Trial Testing Oral Amphotericin.

Background: The EnACT trial was a phase 2 randomized clinical trial conducted in Uganda, which evaluated a novel orally delivered lipid nanocrystal (LNC) amphotericin B in combination with flucytosine for the treatment of cryptococcal meningitis. When flucytosine (5FC) is used as monotherapy in cryptococcosis, 5FC can induce resistant Cryptococcus mutants. Oral amphotericin B uses a novel drug delivery mechanism, and we assessed whether resistance to 5FC develops during oral LNC-amphotericin B therapy. Methods: We enrolled Ugandans with HIV diagnosed with cryptococcal meningitis and who were randomized to receive 5FC and either standard intravenous (IV) amphotericin B or oral LNC-amphotericin B. We used broth microdilution to measure the minimum inhibitory concentration (MIC) of the first and last cryptococcal isolates in each participant. Breakpoints are inferred from 5FC in Candida albicans. We measured cerebral spinal fluid (CSF) 5FC concentrations by liquid chromatography and tandem mass spectrometry. Results: Cryptococcus 5FC MIC50 was 4 µg/mL, and MIC90 was 8 µg/mL. After 2 weeks of therapy, there was no evidence of 5FC resistance developing, defined as a >4-fold change in susceptibility in any Cryptococcus isolate tested. The median CSF 5FC concentration to MIC ratio (interquartile range) was 3.0 (1.7-5.5) µg/mL. There was no association between 5FC/MIC ratio and early fungicidal activity of the quantitative rate of CSF yeast clearance (R2 = 0.004; P = .63). Conclusions: There is no evidence of baseline resistance to 5FC or incident resistance during combination therapy with oral or IV amphotericin B in Uganda. Oral amphotericin B can safely be used in combination with 5FC.

Recently activated CD4 T cells in tuberculosis express OX40 as a target for host-directed immunotherapy.

After Mycobacterium tuberculosis (Mtb) infection, many effector T cells traffic to the lungs, but few become activated. Here we use an antigen receptor reporter mouse (Nur77-GFP) to identify recently activated CD4 T cells in the lungs. These Nur77-GFPHI cells contain expanded TCR clonotypes, have elevated expression of co-stimulatory genes such as Tnfrsf4/OX40, and are functionally more protective than Nur77-GFPLO cells. By contrast, Nur77-GFPLO cells express markers of terminal exhaustion and cytotoxicity, and the trafficking receptor S1pr5, associated with vascular localization. A short course of immunotherapy targeting OX40+ cells transiently expands CD4 T cell numbers and shifts their phenotype towards parenchymal protective cells. Moreover, OX40 agonist immunotherapy decreases the lung bacterial burden and extends host survival, offering an additive benefit to antibiotics. CD4 T cells from the cerebrospinal fluid of humans with HIV-associated tuberculous meningitis commonly express surface OX40 protein, while CD8 T cells do not. Our data thus propose OX40 as a marker of recently activated CD4 T cells at the infection site and a potential target for immunotherapy in tuberculosis.

Finger-Prick Whole Blood Cryptococcal Antigen Lateral Flow Assay for the Diagnosis of Cryptococcosis in HIV-Negative Patients: A Case Series Study in Two Tertiary Centers in São Paulo, Brazil.

Cryptococcosis in HIV-negative patients can be an opportunistic or endemic disease. There are no published studies on the use of the finger-prick whole blood (point-of-care) cryptococcal antigen lateral flow assay (CrAg LFA) for diagnosing cryptococcosis in HIV-negative patients. We conducted a case series study of HIV-negative patients with cryptococcosis in two centers in São Paulo, Brazil. The objectives were to identify the sensitivity of a finger-prick whole blood CrAg LFA and to describe the main characteristics of this population. We identified 30 HIV-negative patients with cryptococcosis [19 (63%), male; median age, 47 years]. Ten (33%) patients were immunosuppressed, ten (33%) had other comorbidities, and ten (33%) were apparently immunocompetent and without comorbidities. The distribution of the sites of cryptococcosis was as follows: the central nervous system, 90% (n = 27); pulmonary, 43% (n = 13); and other extrapulmonary sites, 40% (n = 12). The sensitivity of the finger-prick whole blood CrAg LFA for the diagnosis of cryptococcosis was 97% (29/30). Among 26 participants with cryptococcal meningitis, the sensitivity of testing cerebrospinal fluid was as follows: CrAg latex agglutination, 77% (20/26); CrAg LFA, 96% (25/26); and culture, 81% (21/26). Culture speciation identified Cryptococcus gattii in 16 (62%) cases, and all had a positive finger-prick whole blood CrAg LFA. This test presented high sensitivity to the diagnosis of cryptococcosis in HIV-negative patients, including those caused by C. gattii.

Higher-Dose Fluvoxamine and Time to Sustained Recovery in Outpatients With COVID-19: The ACTIV-6 Randomized Clinical Trial.

Importance: The effect of higher-dose fluvoxamine in reducing symptom duration among outpatients with mild to moderate COVID-19 remains uncertain. Objective: To assess the effectiveness of fluvoxamine, 100 mg twice daily, compared with placebo, for treating mild to moderate COVID-19. Design, Setting, and Participants: The ACTIV-6 platform randomized clinical trial aims to evaluate repurposed medications for mild to moderate COVID-19. Between August 25, 2022, and January 20, 2023, a total of 1175 participants were enrolled at 103 US sites for evaluating fluvoxamine; participants were 30 years or older with confirmed SARS-CoV-2 infection and at least 2 acute COVID-19 symptoms for 7 days or less. Interventions: Participants were randomized to receive fluvoxamine, 50 mg twice daily on day 1 followed by 100 mg twice daily for 12 additional days (n = 601), or placebo (n = 607). Main Outcomes and Measures: The primary outcome was time to sustained recovery (defined as at least 3 consecutive days without symptoms). Secondary outcomes included time to death; time to hospitalization or death; a composite of hospitalization, urgent care visit, emergency department visit, or death; COVID-19 clinical progression scale score; and difference in mean time unwell. Follow-up occurred through day 28. Results: Among 1208 participants who were randomized and received the study drug, the median (IQR) age was 50 (40-60) years, 65.8% were women, 45.5% identified as Hispanic/Latino, and 76.8% reported receiving at least 2 doses of a SARS-CoV-2 vaccine. Among 589 participants who received fluvoxamine and 586 who received placebo included in the primary analysis, differences in time to sustained recovery were not observed (adjusted hazard ratio [HR], 0.99 [95% credible interval, 0.89-1.09]; P for efficacy = .40]). Additionally, unadjusted median time to sustained recovery was 10 (95% CI, 10-11) days in both the intervention and placebo groups. No deaths were reported. Thirty-five participants reported health care use events (a priori defined as death, hospitalization, or emergency department/urgent care visit): 14 in the fluvoxamine group compared with 21 in the placebo group (HR, 0.69 [95% credible interval, 0.27-1.21]; P for efficacy = .86) There were 7 serious adverse events in 6 participants (2 with fluvoxamine and 4 with placebo) but no deaths. Conclusions and Relevance: Among outpatients with mild to moderate COVID-19, treatment with fluvoxamine does not reduce duration of COVID-19 symptoms. Trial Registration: ClinicalTrials.gov Identifier: NCT04885530.

Advancing Diagnosis and Treatment in People Living with HIV and Tuberculosis Meningitis.

PURPOSE OF REVIEW: Tuberculous meningitis (TBM) is the most severe form of tuberculosis. Inadequate diagnostic testing and treatment regimens adapted from pulmonary tuberculosis without consideration of the unique nature of TBM are among the potential drivers. This review focuses on the progress being made in relation to both diagnosis and treatment of TBM, emphasizing promising future directions. RECENT FINDINGS: The molecular assay GeneXpert MTB/Rif Ultra has improved sensitivity but has inadequate negative predictive value to "rule-out" TBM. Evaluations of tests focused on the host response and bacterial components are ongoing. Clinical trials are in progress to explore the roles of rifampin, fluoroquinolones, linezolid, and adjunctive aspirin. Though diagnosis has improved, novel modalities are being explored to improve the rapid diagnosis of TBM. Multiple ongoing clinical trials may change current therapies for TBM in the near future.

Cryptococcal meningitis.

Cryptococcus neoformans and Cryptococcus gattii species complexes cause meningoencephalitis with high fatality rates and considerable morbidity, particularly in persons with deficient T cell-mediated immunity, most commonly affecting people living with HIV. Whereas the global incidence of HIV-associated cryptococcal meningitis (HIV-CM) has decreased over the past decade, cryptococcosis still accounts for one in five AIDS-related deaths globally due to the persistent burden of advanced HIV disease. Moreover, mortality remains high (~50%) in low-resource settings. The armamentarium to decrease cryptococcosis-associated mortality is expanding: cryptococcal antigen screening in the serum and pre-emptive azole therapy for cryptococcal antigenaemia are well established, whereas enhanced pre-emptive combination treatment regimens to improve survival of persons with cryptococcal antigenaemia are in clinical trials. Short courses (≤7 days) of amphotericin-based therapy combined with flucytosine are currently the preferred options for induction therapy of cryptococcal meningitis. Whether short-course induction regimens improve long-term morbidity such as depression, reduced neurocognitive performance and physical disability among survivors is the subject of further study. Here, we discuss underlying immunology, changing epidemiology, and updates on the management of cryptococcal meningitis with emphasis on HIV-associated disease.