356. Changing Epidemiology of Carbapenem-Resistant Enterobacteriaceae Bloodstream Infections in United States Veterans Affairs Hospitals, 2004-2014
Session: Poster Abstract Session: HAI: MDRO-GNR/Emerging Resistant Bacterial Pathogens
Thursday, October 5, 2017
Room: Poster Hall CD
Background: Carbapenem-resistant Enterobacteriaceae bloodstream infections (CRE-BSI) have limited treatment options and are associated with significant mortality. Understanding the burden of CRE-BSI in the United States is critical to inform evaluations of interventions to reduce CRE-BSI rates and improve clinical outcomes. The objective of this study was to quantify the incidence of CRE-BSI over time among Veterans Affairs (VA) patients.

Methods: A nationally representative retrospective cohort study among adult patients admitted to any VA hospital from 2004 through 2014. Carbapenem resistance was defined by CLSI breakpoints in effect during a given year. Inclusion criteria were: i) hospital admission; ii) age ≥ 18 years; iii) ≥ 1 blood culture positive for an Enterobacteriaceae species demonstrating resistance to ≥ 1 carbapenem agent per 2015 CDC CRE definitions (including ertapenem). In recurrent CRE-BSI, only the first case was included. Incidence densities of CRE-BSI were compared year-by-year (overall and by CRE species category) using linear regression analysis.

Results: A total of 1,301 CRE-BSI cases were observed over the study period, corresponding to an overall incidence of 1.79 cases/10,000 hospitalizations. There was a profound increase in the incidence of CRE-BSI from 1.08 cases/10,000 hospitalizations in 2004 to 2.24 cases/10,000 hospitalizations in 2009. Following a decrease in incidence in 2010 (1.61 cases/10,000 hospitalizations), rates of CRE-BSI increased again by 2014 (1.90 cases/10,000 hospitalizations). The majority of CRE-BSI cases were due to Klebsiella pneumoniae (n=638; 49.0%), followed by Enterobacter species (n=188; 14.5%), Proteus species (n=148; 11.1%), and Escherichia coli (n=120; 9.2%). The incidence of CRE-BSI caused by Proteus species increased from 0.19 cases/10,000 hospitalizations in 2009 to 0.38 cases/10,000 hospitalizations in 2014. In contrast, the incidence of CRE-BSI caused by Escherichia coli decreased from 0.29 cases/10,000 hospitalizations in 2009 to 0.10 cases/10,000 hospitalizations in 2014.

Conclusion: In a national sample of hospitalized VA patients, marked changes in the incidence of CRE-BSI were observed from 2004-2014. Rates of CRE-BSI caused by Proteus species appear to be increasing and rates of CRE-BSI caused by Escherichia coli appear to be decreasing.

Nicholas S. Britt, PharmD, MS, Research Department, Dwight D. Eisenhower Veterans Affairs Medical Center, Leavenworth, KS; Barnes-Jewish Hospital, Saint Louis, MO, Nimish Patel, PharmD, PhD, Albany College of Pharmacy & Health Sciences, Albany, NY, Emily M. Potter, PharmD, Dwight D. Eisenhower Veterans Affairs Medical Center, Leavenworth, KS and Molly E. Steed, PharmD, University of Kansas School of Pharmacy, Lawrence, KS

Disclosures:

N. S. Britt, Merck & Co., Inc.: Grant Investigator , Consulting fee
Gilead Sciences, Inc.: Grant Investigator , Consulting fee

N. Patel, Gilead Sciences, Inc.: Grant Investigator , Research grant
Merck & Co., Inc.: Grant Investigator , Consulting fee
Theravance Biopharma US, Inc.: Board Member and Speaker's Bureau , Speaker honorarium

E. M. Potter, None

M. E. Steed, Merck & Co., Inc.: Grant Investigator , Research grant

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