Risk factors for mortality among carbapenem-resistant enterobacteriaceae carriers with focus on immunosuppression.

Objectives: To identify risk factors for mortality in a cohort of carbapenem-resistant enterobacteriaceae (CRE) carriers, focusing on immunosuppression and other risk factors known at the time of CRE carriage detection.

Methods: We prospectively followed all new and known CRE carriers admitted between June 2016 and June 2017 to a single tertiary center in Israel. Patients were included in the study after confirmation of the carrier state. Demographic and clinical data were documented on admission or CRE acquisition and patients were followed prospectively post-discharge until January 2018 or death. Risk factors for mortality known at the time of the first encounter with a CRE carrier were sought. Adjusted hazard ratios (HR) for mortality at end of follow-up with 95% confidence intervals (CI) were assessed using Cox regression analysis.

Results: A total of 115 patients were included in the analysis. During the study period, 66 (57.4%) patients died. Immunosuppression was associated with mortality (HR 1.95, CI 95% 1.12-3.44), adjusted to the Charlson co-morbidity score, functional status, chronic renal disease and Klebsiella pneumonia CRE, the latter three also significantly associated with mortality. CRE bacteremia occurred among 24 (20.9%) carriers during follow up, more frequently among immunosuppressed patients and was significantly associated with mortality at end of follow-up (p = 0.015).

Conclusion: Immunosuppression is independently associated with mortality among CRE carriers, possibly related to CRE bacteremia that is frequent among these patients. Further research is needed on interventions to prevent deaths among CRE carriers.