Predictors of Mortality in Bloodstream Infections: Pathogens, Infection Sources, and Comorbidities

Objective To identify risk factors influencing mortality in critically ill patients with bloodstream infections (BSIs). Methods We analyzed 2789 BSI patients diagnosed by positive blood culture between 2013 and 2023. Multivariate regression analysis was employed to assess the impact of pathogen type, underlying diseases, and infection sources on mortality. Results Overall in-hospital death was 32.3%in BSIs. Predominant pathogens were Escherichia coli (31.7%), and Klebsiella pneumoniae (14.3%). Common comorbidities included cancer (15.6%), and hematologic malignancies (14.5%). Primary infection sources were urinary tract (17.0%) and biliary tract (12.7%). Significant mortality predictors were: polymicrobial infection (OR 2.3, 95% CI 1.7-4.0), Acinetobacter baumannii (OR 2.9, 95% CI 1.7-5.0), Candida spp. (OR 6.7, 95% CI 3.5-12.9), Enterococcus spp. (OR 2.4, 95% CI 1.4-4.0), Streptococcus pneumoniae (OR 2.2, 95% CI 1.1-4.43); pulmonary (OR 2.1, 95% CI 1.6-2.8), abdominal (OR 1.9, 95% CI 1.4-2.7), intracranial (OR 2.7, 95% CI 1.4-5.3), and enterogenic BSIs (OR 1.7, 95% CI 1.3-2.3); solid tumors (OR 2.4, 95% CI 1.9-3.18), hematologic malignancies (OR 2.5, 95% CI 1.9-3.2), cerebrovascular disease (OR 2.4, 95% CI 1.6-3.5), multiple trauma (OR 1.8, 95% CI 1.3-2.6), and digestive tract damage (OR 2.1, 95% CI 1.3-3.6). All reported associations were statistically significant (p<0.01). Conclusion In this cohort, BSIs due to Candida , pulmonary or abdominal sources, and in patients with cancers or hematologic malignancies were associated with higher mortality predictors of death.