The clinical impact of Stenotrophomonas maltophilia bacteremia on the 30-day mortality rate in patients with hematologic disorders: a single-institution experience

Objective Stenotrophomonas maltophilia (SM) is an important nosocomial pathogen, particularly in immunocompromised patients due to their adverse antimicrobial susceptibility pattern. The objective of this article was to investigate the clinical impact of SM bacteremia on the 30-day mortality rate and identify the risk factors of the cause of mortality in patients with hematologic disorders. Methods We retrospectively reviewed the clinical data in patients diagnosed with hematological disorders and SM bacteremia over an 8-year period from July 2010 to July 2018 at a 248-bed hematology department. We compared patients' clinical characteristics and outcomes between the non-survivor and survivor groups. Results The overall incidence of SM bacteremia was 25.1 per 10,000 admissions. There were 59 patients (median age: 35 years; 57.6% males) included in the study with an overall SM bacteremia-related 30-day mortality of 44.1%. Multi-drug resistance was common. In vitro susceptibility is higher to ceftazidime (72.9%), ciprofloxacin (66.1%) and cefoperazone/sulbactam (59.3%). The risk factors identified in the univariate analysis were catheter re-implantation, accompanying polymicrobial infection, inadequate initial antimicrobial treatment, APACHE II score, temperature > 39 degrees C, septic shock, respiratory failure, and non-remission post treatment for primary diseases. Multivariate analysis further confirmed that inadequate initial antimicrobial treatment, respiratory failure, and non-remission after treatment for hematological diseases are independent risk factors associated with mortality (P = 0.001, 0.002 and 0.007, respectively). Conclusions Our study suggests that SM bacteremia is highly associated with increased mortality in patients with hematologic diseases. Early detection, prompt comprehensive management including initiation of combined sensitive antibiotics, respiratory monitoring and support, platelet infusion, and strategies to improve patients' remission status are recommended to improve the overall survival in patients with SM bacteremia.