533. Impact of Different Definitions on Reported Rates of Carbapenem-Resistant Enterobacteriaceae (CRE)

BACKGROUND: Different definitions exist for tracking and trending rates of hospital-acquired Carbapenem-resistant Enterobacteriaceae (CRE). National Health Safety Network (NHSN) allows for Laboratory Identified Event (LabID) and Healthcare-associated infection (HAI) surveillance reporting for CRE. Our facility developed an internal definition for CRE prior to release of the NHSN modules that differs from the CDC definitions in that patients colonized or infected with CRE identified on hospital day 1 or 2 who had a hospitalization within the past four weeks are considered community-onset healthcare facility acquired (COHCFA) and are included in our HA definition. In addition, by our definition once a patient develops CRE any subsequent positive cultures for the same organism are not considered new events. METHODS: All CRE cultures at our facility were reviewed by an infection preventionist and hospital epidemiologist who categorized each culture as hospital acquired by our internal HA definition, NHSN LabID definition and NHSN HAI definition. Results from each method of surveillance were compiled and compared as were trends of HA CRE over time by each definition. RESULTS: 590 patients with 975 clinical cultures for Carbapenem-resistant Klebsiella spp., Enterobacter spp and E. coli were reviewed from January 2012 to March 2019. 297 cultures met our internal definition for HA CRE compared with 302 by NHSN LabID and 189 by NHSN HAI surveillance. Sixty-one (21%) of HA cases by our definition were COHCFA. 259 patients had multiple CRE cultures and 1 patient had 22 cultures with the same CRE organism between 2014 and 2019 and met for 5 lab ID events and 5 NHSN HAI events. All 3 tests agreed that a culture was HA in 140 instances (14%) and all 3 agreed that a culture was not HA in 589 instances (60%). At least one definition yielded a discordant result in 246 cultures (25%). Trends over time were compared between the definitions. While the number of HA cases varied based on the definition used, overall trends over time were similar regardless of the definition utilized. (Figure 2) CONCLUSION: Regardless of the definition used for surveillance of CRE, trends over time are similar. Consideration should be given to monitoring COHCFA cases in addition to those acquired on or after hospital day 3. [Image: see text] DISCLOSURES: All authors: No reported disclosures.