1815. The risk of mortality following healthcare-associated infections due to Gram-negative bacteria
Session: Poster Abstract Session: Resistant Gram-Negative Infections: Epidemiology
Saturday, October 10, 2015
Room: Poster Hall


While many studies have estimated the impact of healthcare-associated infections (HAIs) on mortality during the initial hospitalization, little is known about the long-term risk of death in these patients. The purpose of this study was to quantify the effect of multi-drug resistant (MDR) gram-negative bacteria HAIs on mortality after hospital discharge.


The study cohort consisted of patients with an inpatient admission within the US Department of Veterans Affairs (VA) system between 10/1/2007 and 11/30/2010. We used electronic microbiology reports to identify those with a positive culture for an MDR gram-negative bacterium (Acinetobacter, Pseudomonas aeruginosa, and Enterobacteriaceae). We distinguished between definite HAIs, defined by normally sterile culture sites, and possible HAIs, defined by unsterile sites, which might also include colonization. We constructed multivariable logistic regressions to assess the impact of a positive culture on mortality in the 30 and 90 days following infection using a propensity score-matched subsample. For each patient with a positive culture, 4 matched control patients were selected from a pool of eligible patients who had not had an MDR gram-negative HAI on or before the hospital day on which the corresponding case had HAI onset.


Patients identified with HAIs due to Acinetobacter (n = 212), Pseudomonas aeruginosa (n = 1,012), or Enterobacteriaceae (n = 3,485) were propensity score matched to 15,506 control patients. The adjusted odds ratios are presented in Table 1.


Both possible and, especially, definite HAIs due to MDR gram-negative bacteria significantly elevate the 30- and 90-day risk of mortality. Prevention of MDR gram-negative HAIs may significantly reduce post hospitalization mortality.

Richard E. Nelson, PhD1, Rachel Slayton, PhD, MPH2, Vanessa Stevens, PhD1, Makoto Jones, MD, MS3, Karim Khader, PhD1, Michael Rubin, MD, PhD, FIDSA4, John Jernigan, MD, MS5 and Matthew Samore, MD, FSHEA6, (1)Ideas Center, VA Salt Lake City Health Care System, Salt Lake City, UT, (2)Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, GA, (3)Internal Medicine, University of Utah School of Medicine Division of Epidemiology, Salt Lake City, UT, (4)Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT, (5)Centers for Disease Control and Prevention, Atlanta, GA, (6)University of Utah School of Medicine, Division of Epidemiology, Salt Lake City, UT


R. E. Nelson, None

R. Slayton, None

V. Stevens, None

M. Jones, None

K. Khader, None

M. Rubin, None

J. Jernigan, None

M. Samore, None

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