RETROSPECTIVE STUDY ON BACTERIAL MENINGITIS IN ADULTS: EPIDEMIOLOGY, CLINICAL FEATURES, PREDICTORS AND OUTCOMES OF MEDICAL AND SURGICAL MANAGEMENT

Background and Objective Acute bacterial meningitis (ABM) is a medical emergency associated with high morbidity and mortality in adults. This study aimed to analyze the epidemiological, clinical, and therapeutic characteristics of adult patients with ABM, to identify predictors of poor outcomes, and to evaluate the role of both medical and surgical management. Methods This retrospective multicenter study was conducted on adult patients diagnosed with ABM between 2014 and 2025 in two Italian regions (Emilia-Romagna and Sicily). Demographic, clinical, laboratory, radiological, and therapeutic data were collected. Outcome was defined as 30-day mortality and neurological sequelae. Descriptive and univariate analyses were conducted to characterize the patient population and identify factors associated with adverse outcomes Results A total of 106 patients were included (79 from Emilia Romagna 27 from Sicily). Majority of them were unvaccinated against the main bacterial pathogens (86.8%). Streptococcus pneumoniae was the most frequently identified pathogen (48.1%). Nearly all patients received effective empiric antibiotic therapy (91.5%), along with adjunctive corticosteroid treatment. In terms of outcomes, 25.5% of patients experienced an unfavorable outcome, defined as death or neurological sequelae. Approximately one third of patients (30.3%) underwent surgery, mainly for mastoidectomy or repair of a cerebrospinal fluid fistula. When comparing early versus delayed surgical intervention, no predictive factors associated to death or neurological sequelae were found, but patients who underwent delayed surgery (>72h) had a significantly longer stay in the intensive care unit (p. 0.018). Factors associated with unfavorable outcomes—including death and neurological sequelae—were a low Glasgow Coma Scale score at admission, septic shock, and multiorgan failure (p 0.001). Conclusions ABM in adults remains a life-threatening condition with a high risk of severe complications, even when appropriately treated. Early identification of prognostic factors may help tailor clinical management. These findings further underscore the importance of vaccination in preventing severe forms of bacterial meningitis and reducing associated morbidity and mortality.