1259. The Local Hospital Milieu and Healthcare-Associated VRE Acquisition

Abstract Background The relationship between the local hospital environment and VRE acquisition is not fully understood. The objective of this study was to identify risk factors for healthcare-associated VRE acquisition related to the local hospital milieu. Methods This retrospective cohort study included patients admitted to six ICUs at an academic medical center from January 1, 2012 to December 31, 2016 with negative rectal VRE cultures on admission. VRE acquisition was defined as a positive subsequent surveillance swab performed at any time after the initial negative surveillance swab during the index hospitalization. VRE colonization pressure was defined to encapsulate the circulating VRE burden during the at-risk patient’s ICU stay (patient-days of VRE exposure based on concurrently colonized patients on the unit, divided by time at risk). VRE importation pressure was defined to encapsulate the VRE burden at the time of ICU admission (patient-days of VRE exposure on the unit during the preceding 30 days, divided by total patient-days). Multivariable Cox proportional hazards modeling was used, with patients followed until VRE acquisition, death, or for up to 30 days. Results There were 161 patients who acquired VRE among 8,485 patients with negative VRE cultures upon admission, including 1,131 patients who had repeat VRE cultures during the index hospitalization. On univariate analysis, patients with VRE acquisition were more likely to have received vancomycin, have had a neighboring patient who received vancomycin, have high VRE importation pressure, or have high VRE colonization pressure. On multivariable analysis, among these factors only high VRE colonization pressure was an independent predictor of VRE acquisition (aHR 1.79, 95% CI 1.19–2.70). Conclusion VRE colonization pressure was the most important risk factor for healthcare-associated VRE acquisition in this ICU population, regardless of VRE importation pressure or local use of vancomycin. Interventions seeking to reduce healthcare-associated VRE acquisition may wish to focus on ways to minimize transmission of VRE between patients with known VRE and the local hospital environment. Disclosures All authors: No reported disclosures.