Prevalence and factors associated with carbapenem-resistant Enterobacterales (CRE) infection among hematological malignancies patients with CRE intestinal colonization

Background Knowledge about the prevalence, factors and mortality associated with subsequent carbapenem-resistant Enterobacterales (CRE) infection among hematological malignancies (HM) patients colonized with CRE is limited. Methods HM patients were screened for rectal CRE. A retrospective case–control study of subsequent CRE infection among HM patients colonized with CRE was conducted between January 1st, 2020 and January 31st, 2022. Cases were defined as CRE colonized patients with subsequent infection and controls were those without infection. Bacterial identification was performed using MALDI Biotyper and antimicrobial susceptibility testing of strains was carried out using the VITEK 2 system or standard broth microdilution method. Logistic analysis was used for analyzing associated factors and Kaplan–Meier method was used for survival estimates. Results A total of 953 HM patients were screened for rectal CRE and 98 (10.3%, 98/953) patients were colonized with CRE. Among the 98 colonized patients, 18 (18.4%, 18/98) patients developed subsequent infection. Most of the colonizing CRE isolates were Klebsiella pneumoniae (50.0%, 27/54), followed by Escherichia coli (27.8%, 15/54) and Enterobacter cloacae (9.3%, 5/54). As for the subsequent infecting CRE isolates, the dominated species was K. pneumoniae (55.6%, 10/18), followed by E. coli (33.3%, 6/18) and others (11.2%, 2/18). Receiving proton pump inhibitors and admission to ICU ( P < 0.05 ) were the associated factors. Patients with subsequent CRE infection had significant higher mortality (33.3% vs 2.8%, P = 0.001) and shock was an associated factor (P = 0.008). Conclusions Klebsiella pneumoniae was the dominate colonizing species and subsequent infecting species among HM patients with CRE colonization. Receiving proton pump inhibitors and admission to ICU increased the risk of subsequent CRE infection among CRE colonized HM patients. Implementing strict infection control measures targeting those high- risk patients may prevent subsequent CRE infection.