Recurrence and mortality after Pseudomonas aeruginosa bloodstream infection: a population-based cohort study

Pseudomonas aeruginosa bloodstream infections pose challenges due to recurrence and mortality. Identifying these outcomes may support more targeted empiric therapy.

A population-based cohort study was conducted in Queensland (2000-2019). Patients were classified into four outcomes. Multinomial (relative risk ratios [RRR]) and binary logistic regression (with odds ratio [OR]) identified baseline factors associated with recurrence and mortality.

Among 5,742 patients with P. aeruginosa BSI, 20.5% died within 30 days, 21.3% died between 30 days and three years, 4.6% experienced recurrence, and 53.6% survived to three years without recurrence. Factors associated with recurrence included malignancy (RRR 3.43; 95% CI 2.55-4.62), metastatic cancer (RRR 2.16; 95% CI 1.27-3.66), and uncomplicated diabetes (RRR 2.25; 95% CI 1.31-3.86). Mortality was associated with malignancy (OR 2.65; 95% CI 2.22-3.16), congestive heart failure (OR 1.67; 95% CI 1.38-2.04), dementia (OR 1.97; 95% CI 1.46-2.65), renal disease (OR 1.85; 95% CI 1.55-2.19), pulmonary disease (OR 1.32; 95% CI 1.08-1.62), and advancing age (OR 1.02; 95% CI 1.02-1.03). Community-onset infections and a genitourinary source were associated with a reduced risk of both recurrence (RRR 0.52; 95% CI 0.33-0.81 and RRR 0.70; 95% CI 0.43-1.14) and mortality (OR 0.68; 95% CI 0.55-0.85 and OR 0.66; 95% CI 0.52-0.84, respectively). Among patients with recurrence, resistance emerged to ceftazidime (10.7%), and ciprofloxacin (10.1%), although most susceptibility profiles remained stable.

Among patients with P. aeruginosa BSI, rates of mortality and clinically relevant recurrence were high. These findings may assist clinicians in making more informed empiric treatment decisions.