Clinical Characteristics, Microbiology, and Risk Factors for Mortality of Pre-Engraftment and Post-Engraftment Bloodstream Infection in Hematopoietic Stem Cell Transplantation Recipients.

Background: Bloodstream infection (BSI) is a common and serious complication that may lead to high mortality during the different phases after hematopoietic stem cell transplant (HSCT). We investigated BSI in patients undergoing HSCT to provide an appropriate clinical anti-infection experience and improve the prognosis of recipients with BSI after HSCT. Methods: A total of 105 patients with BSI after HSCT at our center from January 2015 to June 2020 were included in this retrospective study. We analyzed the clinical and microbiological data, and the risk factors for mortality at 3 months after BSI. Results: Of the 1141 HSCT recipients, 105 (9.2%) patients presented with 122 episodes of BSI, of which we isolated 85 (65.9%) gram-negative bacteria, 32 (24.8%) gram-positive bacteria and 12 (9.3%) fungi. Multidrug-resistant bacteria (MDR) were more than 70% of all pathogens and carbapenem-resistant organisms (CRO) were 25.6%. There were 55 episodes of BSI in the pre-engraftment phase and 67 episodes in the post-engraftment phase. The mortality of post-engraftment BSI was significantly higher than that of pre-engraftment (56.7% vs 32.7%, p = 0.005). Through multivariate analysis, the independent risk factors for all-cause mortality at 3 months after BSI were higher levels of procalcitonin (PCT), failure to cover appropriate antibiotics timely, and CRO BSI in pre-engraftment period or multidrug-resistant gram-negative bacteria (MDRGNB) BSI in post-engraftment period. Conclusion: Although the incidence of BSI was lower after HSCT, MDR-dominated BSI had a high mortality rate. Rapid identification of infection or pathogens' classification with various testing methods and the more sensible and timely antibiotic cover are critical to the outcome of BSI after HSCT.