493. Laboratory Evaluation and Epidemiology of Carbapenemase-Producing Carbapenem-Resistant Enterobacteriaceae in Department of Veterans Affairs, 2017

BACKGROUND: Carbapenemase-producing (CP)-carbapenem-resistant Enterobacteriaceae (CRE) pose a major threat to public health and are a priority target of national prevention and control efforts including within Department of Veterans Affairs (VA). The laboratory evaluation and epidemiology of CRE in VA is uncertain. METHODS: Using data from the Veterans Health Administration Corporate Data Warehouse, we identified all Veterans with ≥1 CRE result obtained during 2017 and reviewed their electronic health record. Two case definitions were used: (1) 2015 CDC CRE (Enterobacteriaceae resistant to any carbapenem or with documented carbapenemase production) and (2) 2017 VA CP-CRE (E. coli, Klebsiella spp., and Enterobacter spp. resistant to imipenem, meropenem, or doripenem or with documented carbapenemase production). Patients harboring carbapenemase-producers detected by rectal screening tests only were included. We reviewed patient charts whose isolates met both CRE definitions, extracting detailed microbiologic and travel data for the first positive 2017 result. RESULTS: We identified 904 unique Veterans with CRE; 577 (64%) patients had results meeting both CRE case definitions while 327 (36%) had results meeting CDC CRE criteria only (Figure 1). Of the 458 patients with clinical isolates meeting both case definitions, urine specimens predominated (64%) and were associated with the lowest crude 90-day mortality (16%); mortality was highest amongst patients with respiratory tract cultures (40%) and bloodstream isolates (34%) (Figure 2). Nearly half (48%) of VA CP-CRE were tested for carbapenemases (76% in-house; 24% send-out); of these, 75%tested positive with 78% being a KPC, 1% NDM, and 21% unspecified (Figure 3). Additionally, all 119 CRE carriers with an identified gene had KPC. Only 7 patients (1%) had documented overseas travel. CONCLUSION: Currently the incidence of CP-CRE in the nation’s largest healthcare system is low relative to other problem pathogens such as MRSA and Clostridioides difficile but is associated with a high crude mortality especially with respiratory and bloodstream isolates. KPC comprised almost all carbapenemases identified. This provides an initial, granular snapshot of CRE in VA to serve as a roadmap for ongoing CP-CRE prevention and control. [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.