Predictors of mortality and clinical outcomes in adult bacterial meningitis in Northern Vietnam: A seven-year cohort analysis

BACKGROUND: Bacterial meningitis remains a major cause of neurological morbidity and mortality, particularly in low- and middle-income countries. To better characterise the aetiology, clinical features and prognostic determinants, we conducted a seven-year investigation of adult bacterial meningitis cases admitted to a large tertiary hospital in northern Vietnam. METHODS: A retrospective-prospective observational cohort study was conducted between 2018 and 2024, including adults diagnosed with bacterial meningitis. Clinical characteristics, cerebrospinal fluid (CSF) parameters, culture results and targeted in-house PCR findings were analysed. Outcomes were assessed using Glasgow Outcome Scale (GOS), with unfavourable outcomes defined as GOS 1-4. Multivariate logistic regression identified independent predictors of mortality and unfavourable outcomes. RESULTS: Of 232 screened patients, 150 met inclusion criteria. Pathogens were identified in 62 (41%) cases. Streptococcus suis was the predominant pathogen (n = 26), followed by Streptococcus pneumoniae (n = 10). CSF culture yielded growth in 35% of cases, while PCR detected six additional culture-negative infections. Overall mortality was 5% and 10% of patients experienced unfavourable outcomes. Independent predictors included alcoholism (unfavourable outcome OR 13.8, 95% CI 2.1-100; mortality OR 16.5, 95% CI 1.9-165), focal neurological deficits (unfavourable outcome OR 41.4, 95% CI 9.2-250; mortality OR 12.8, 95% CI 1.7-123) and altered mental status (OR 8.6, 95% CI 1.5-86). CONCLUSIONS: S. suis remains the leading cause of adult bacterial meningitis in Northern Vietnam. Targeted interventions addressing high-risk groups, particularly individuals with alcoholism or neurological deficits at presentation, could improve clinical outcomes.