Epidemiology, resistant pathogens, and causes of early death in cases of bloodstream infection in patients with hematological malignancies from 2012–2019

To investigate the epidemiology, causative pathogen antibiotic susceptibility, and mortality risk factors of bloodstream infection (BSI) in patients with hematological malignancies (HMs).

Single-center retrospective analysis of BSI cases in patients with HMs in a Chinese tertiary hospital from 2012–2019.

Among 17,796 analyzed admissions, 508 BSI episodes (2.9%; 95% confidence interval: 2.6%–3.2%) were identified. Of 522 resulting isolates, 326 (62.5%) were Gram-negative, 173 (33.1%) were Gram-positive. The BSI incidence among patients with different HMs (severe aplastic anemia: 6.7%; acute leukemia: 6.2%; myelodysplastic syndrome: 3.2%; multiple myeloma: 1.3%; and lymphoma: 1.0%) differed significantly (p < 0.001). The BSI incidence was significantly higher in the hematopoietic stem cell transplantation (HSCT) group (10.2%) than in the non-HSCT group (2.5%; p < 0.001). Escherichia coli (30.7%, 160/522) was the most common pathogen, followed by Coagulase-negative staphylococci (19.4%, 101/522) and Klebsiella pneumoniae (10.0%, 52/522)., The rates of imipenem resistance for E. coli, K. pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii were 6.4%, 15.0%, 27.8%, and 79.0%, respectively. All the Gram-positive pathogens were linezolid susceptible. Three vancomycin-resistant Enterococcus species were isolated. The overall 14-day mortality was 9.8% (95% confidence interval: 7.2%–12.4%). A multivariate analysis showed that HM subtype severe aplastic anemia, A. baumannii, and malignancy non-remission were independent 14-day mortality risk factors.

Gram-negative bacteria were the most common pathogens, with E. coli as the predominant strain, causing BSIs in HM patients. A carbapenem-resistant A. baumanni with a high mortality rate in HM patients made empirical antimicrobial choice a highly challenging issue.