Epidemiology, Microbiology, and Risk Factors of Bacterial Bloodstream Infections in Patients After Allogeneic Hematopoietic Stem Cell Transplantation.

PURPOSE: To investigate the clinical characteristics, etiology, and risk factors of bacterial bloodstream infection (BSI) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. This study also aimed to provide a clinical basis for early identification of high-risk patients and optimization of empirical antimicrobial treatment.

PATIENTS AND METHODS: This is a retrospective study of clinical data during agranulocytosis from 331 patients with hematological malignancies who underwent allo-HSCT at our institute between January 2016 and December 2022. The incidence, distribution and drug resistance patterns, and the risk factors of BSI were analyzed.

RESULTS: Among the 331 HSCT patients, 250 had febrile neutropenia and 45 cases were found to have BSI. The incidence of BSI in patients with agranulocytosis fever was 18% (45/250). A total of 48 pathogens were isolated during BSI episodes, gram-negative bacteria (GNB) accounted for 70.8% (34/48), gram-positive bacteria (GPB) for 29.2% (14/48). Multivariate analysis revealed that ≥grade 2 acute graft-versus-host disease (aGVHD) and previous BSI within 6 months before HSCT were independently associated with an increased occurrence of BSI. Coagulase-negative staphylococci (CoNS) and Escherichia coli were the most commonly isolated GPB and GNB, respectively. A total of 32 GNB were tested for drug susceptibility, the detection rate of carbapenem-resistant Enterobacteriaceae (CRE) was 12.5% (4/32), and extended-spectrum β-lactamase (ESBL) accounted for 56.3% (18/32).

CONCLUSION: BSIs are still a common and severe complication after allo-HSCT. In our center, BSIs in allo-HSCT patients are dominated by gram-negative bacteria and the resistance rate to carbapenem drugs is high. Risk factors for BSI during agranulocytosis were previous BSI within 6 months before HSCT and ≥grade 2 aGVHD.