Profiles of primary brain abscesses and their impact on survival: An international ID-IRI study

This study of 331 primary brain abscess (PBA) patients aimed to understand infecting agents, predisposing factors, and outcomes, with a focus on factors affecting mortality.

Data were collected from 39 centers across 16 countries between January 2010 and December 2022, and clinical, radiological, and microbiological findings, along with their impact on mortality, were analyzed.

The patients had a mean ± SD age of 46.8 ± 16.3 years, with a male predominance of 71.6%. Common symptoms included headache (77.9%), fever (54.4%), and focal neurological deficits (53.5%). Gram-positive cocci were the predominant pathogens, with Viridans group streptococci identified as the most frequently isolated organisms. All patients received antimicrobial therapy and 71.6% underwent interventional therapies. The 42-day and 180-day survival rates were 91.9% and 86.1%, respectively. Significant predictors of 42-day mortality included intravenous drug addiction (HR: 6.02, 95% CI: 1.38-26.26), malignancy (HR: 3.61, 95% CI: 1.23-10.58), confusion (HR: 2.65, 95% CI: 1.19-5.88), and unidentified bacteria (HR: 4.68, 95% CI: 1.76-12.43). Significant predictors of 180-day mortality included malignancy (HR: 2.70, 95% CI: 1.07-6.81), confusion (HR: 2.14, 95% CI: 1.11-4.15), temporal lobe involvement (HR: 2.10, 95% CI: 1.08-4.08), and unidentified bacteria (HR: 3.02, 95% CI: 1.49-6.15).

The risk of death in PBA extends beyond the infection phase, with different factors influencing the 42-day and 180-day mortality rates. Intravenous drug addiction was associated with early mortality, while temporal lobe involvement was associated with late mortality.