Pathogen-Specific Burden of Adult Bacterial Meningitis
BACTERIAL meningitis remains a significant public health challenge, with high mortality and persistent neurological complications among survivors. A landmark nationwide Dutch study, spanning 18 years and including 2,974 adult patients, provides an unprecedented pathogen-specific assessment of outcomes, revealing critical insights for infectious disease specialists and healthcare providers.
Study Design and Patient Cohort
Researchers prospectively identified adults with community-acquired bacterial meningitis confirmed via lumbar puncture, using the Netherlands Reference Laboratory database. Neurological examinations were performed at admission and discharge, with outcomes evaluated using the Glasgow Outcome Scale. Mortality and unfavourable outcomes were tracked alongside detailed analysis of pathogen-specific effects, risk factors, and long-term sequelae.
Mortality and Neurological Outcomes
Overall mortality remained high at 17%, with pathogen-specific differences: Listeria monocytogenes accounted for the highest fatality rate (32%), followed by Streptococcus pyogenes (19%) and Streptococcus pneumoniae (18%). Unfavourable outcomes, including death or severe neurological impairment, affected 39% of patients. Survivors frequently experienced long-term neurological sequelae: 55% had complications, including hearing loss (31%) and cognitive impairment (23%), with rates particularly elevated after S. pneumoniae (62%) and S. pyogenes (75%) infections.
Risk Factors for Unfavourable Outcomes
Multivariate analysis highlighted several predictors of poor outcomes: advanced age, prolonged symptom duration before hospital presentation, systemic or cerebral compromise, low cerebrospinal fluid white-cell counts, and absence of adjunctive dexamethasone therapy. These findings reinforce the importance of early recognition, rapid intervention, and appropriate adjunctive therapy in mitigating disease burden.
Implications for Prevention and Treatment
Despite a 90% adherence to adjunctive dexamethasone treatment, outcomes have not improved over nearly two decades, emphasising the persistent clinical challenge of bacterial meningitis. The study shows the urgent need for enhanced preventive strategies, particularly vaccination programmes targeting high-risk pathogens, timely diagnosis, and clinical trials evaluating new adjunctive therapies aimed at reducing central nervous system inflammation.
By providing a detailed pathogen-stratified analysis, this study equips clinicians with actionable data on prognosis and risk stratification. Knowledge of which pathogens carry higher mortality and long-term sequelae can guide prioritisation of preventive measures, rapid therapeutic interventions, and patient counselling.
Reference
Drost EHGM et al. Outcomes of adults with community-acquired bacterial meningitis in the Netherlands: a prospective nationwide cohort study. Lancet Reg Health Eur. 2026; DOI:10.1016/j.lanepe.2025.101529.
