Clinical characteristics and risk factors for mortality in patients with hematological malignancy infected with Stenotrophomonas maltophilia

Stenotrophomonas maltophilia ( S. maltophilia ) is a clinically important pathogen, yet there is currently limited research on the clinical outcomes and risk factors for infections caused by S. maltophilia in patients with hematological malignancy. Our objective was to describe the epidemiology and prognostic factors associated with S. maltophilia in patients with hematological malignancy, focusing on clinical therapy. We collected non-duplicate S. maltophilia strains from various clinical specimens (including lower respiratory tract, blood, urine, puncture fluid, upper respiratory tract, feces and tissue) of patients with hematological malignancies at a large tertiary teaching hospital between January 2016 and August 2023. Antimicrobial susceptibility testing (AST) was performed using the VITEK 2 Compact system, and the results were interpreted according to CLSI guidelines. We conducted a retrospective analysis of the clinical features, with a particular focus on clinical outcomes, following infection by leveraging the electronic medical record system. Cox regression analysis was employed to pinpoint the risk factors associated with mortality post-infection. Our results showed that a total of 140 strains of S. maltophilia were collected over the 8-year period. The resistance rates of the strains to levofloxacin(LVX) and Trimethoprim-Sulfamethoxazole (SXT) were 10% (14/140) and 5.7% (8/140), respectively. 87 cases were diagnosed as S. maltophilia infection events. The mortality rate within 30 days after infection was 42.5% (37/87). Ventilator support ( P < 0.001, HR = 8.693, CI = 3.600-20.993), and pulmonary hemorrhage ( P < 0.001, HR = 4.602, CI = 2.191–9.664) were independent predictors of mortality in S. maltophilia infections. We studied the clinical features of S. maltophilia infections in hematological patients with multi-year data and found that infections caused by this strain were associated with a high mortality rate, with pulmonary hemorrhage as an independent risk factor for death, especially following ventilator support. Ongoing pathogen tracking and infection surveillance in haematological patients is important. This study provides new perspectives and strategies for clinical management.