#237 Carbapenemase producing Enterobacteriaceae rectal colonization in dialysis patients: a large monocentric retrospective analysis
Authors: Righini Matteo , Valentini Chiara , Martelli Davide , Samele Gianluca , Mancini Raul , Magnini Caterina , Miselli Filippo , Vara Giulio , La Manna Gaetano , Buscaroli Andrea 
Published: May 2024

Abstract

Background and Aims
Carbapenemase-producing Enterobacteriaceae (CPE) represent a growing global public health concern due to their increasing prevalence and resistance to carbapenems. Dialysis patients are particularly vulnerable to infections that represent the second cause of death in dialysis’ cohorts. Considering the immunosuppression, dialysis patients constitute a highly immunocompromised population and represent a unique setting similar to intensive care, hematology, or transplant recipients. Several studies have already been conducted in these populations, demonstrating the high infectious risk, increased mortality and morbidity burdened by CPE. Our study aims to analyze a large dialysis population and assess if there is an increased risk of mortality, sepsis, and/or hospitalizations within this cohort. Considering the frequency of evaluations for these patients, we have also decided to evaluate the treatments to which these patients are subjected, their antibiotic exposure, the number of hospitalizations and specific infections, while seeking predisposing or protective factors within this specific patient group.

Method
Our work is a retrospective, single-center cohort study that analyzes patients on HD and PD who were followed by the Nephrology and Dialysis Department of the Ravenna Hospital from 01/01/2015 to 31/12/2021 (674 patients). We analyzed demographic data (Date of birth, gender, blood type), comorbidities (Diabetes, hypertension), dialysis data (type of dialysis technique, dialytic age), blood tests (hemoglobin, white blood cells, platelets, albumin, ALT, lipase, C-reactive protein), serology and markers (HBV, HCV, HIV, EBV, CMV, Quantiferon, Helicobacter pylori colonization, SARS-COV2), therapies (antihypertensives, proton pump inhibitors, calcium-based phosphorus binders, non-calcium-based phosphorus binders, potassium binders, iron therapy, erythropoietin-stimulating agents), antibiotics (cephalosporins, penicillins, fluoroquinolones, macrolides, aminoglycosides, carbapenems, tetracyclines, vancomycin, linezolid, cefepime/avibactam), hospitalizations, colonization or lack thereof by CPE bacteria, infections (urinary tract infections and pneumonias) or sepsis and responsible microorganisms, survival. We exclude patients who had stomas or those who received chemotherapy or immunotherapy for a period longer than 3 months.

Results
Overall we considered for our analysis 528 patients and 51 presented CPE positive rectal swab during the period of observation. In our population CPE colonized patients present a higher risk to develop pneumonias (HR 2.048, p = 0.003). 178 patients presented 497 episodes of sepsis, 451 episodes in the non CPE colonized and 46 episodes in the CPE colonized (HR 2.057, p-value 0.001). Considering CPE-induced sepsis, a substantial difference was observed between the two groups. The colonized patient group had 7 (15.2%) cases of CPE sepsis, while the non-colonized group did not have any (0%). The result shows statistical significance, although the limited number of infections does not allow for definitive conclusions on this matter. Concerning the re-hospitalization rate we evidenced a significative difference between the two groups, displaying an involvement of CPE colonization (HR1.367, p-value = 0.038).

Conclusion
Our study highlighted that a colonization by CPE lead to a greater number of episodes of all bacterial sepsis, of CPE sepsis, of pneumonias and of re-hospitalizations. Colonization by CPE conferm an increased risk of CPE sepsis, and therefore, future research should focus on determining whether it is worthwhile to treat hyperpyrexia in colonized CPE dialysis patients as if it were CPE-related sepsis. This is a significant question that can guide our clinical practice.