P1-2-13A retrospective analysis about Stenotrophomas maltophiria sepsis in patients with hematological malignancy

Introduction: Febrile neutropenia (FN) is often observed in hematological malignancy. Most of FN cases are infections by various causative agents rarely including antibiotic-resistant bacteria or low virulent bacilli. Stenotrophomas maltophiria (SM) is a low virulent bacillus widely existing in the environment, a causative agent of opportunistic infection and a rare pathogenic bacteria in FN. On the other hand, some cases of sepsis by SM were reported in FN patients with hematological malignancy. Methods: We reviewed all blood cultures (BCs) data from our single institute from 2004 to 2014, and evaluated retrospectively clinical surveillances of sepsis by Stenotrophomas maltophiria in hematological malignancy. Results: Total 3180 events of BCs were performed when the first line antibiotic agents administration were started for FN patients in the Hematology-Oncology unit of our institute from 2004 to 2014. In the 16.4% of these BCs events, bacterias or fungus were detected. The frequency of BCs positive cases for SM were rarely observed in 2.3% of all BCs events, and total 13 cases of SM sepsis were diagnosed. The primary diagnosis of hematological disease in those SM sepsis cases were NHL(N = 5), AML(N = 4), ALL(N = 3) and CML(N = 1), and almost all of these disease were relapse or refractory cases with long duration treatments. SM detected in 13 cases were widely resistant to many antibiotic agents. Twelve cases died of MOF, and 8 cases died within 7 days after the finding of BCs in spite of intensive care including administration of sensitive antibiotic therapies. Conclusion: The prognosis of SM sepsis in patients with hematological disease was extremely poor. Surveillance for SM infection in high-risk patients is essential, and rapid administrations of appropriate antibiotics should be considered.