375. Characteristics and Predictive Factors for Multidrug-Resistant Gram-Negative Infections in Deployment-Related Trauma Patients
Session: Poster Abstract Session: HAI: Multi Drug Resistant Gram Negatives
Thursday, October 27, 2016
Room: Poster Hall
Background: Bacterial wound infections in severe polytrauma complicate wartime injures. The contribution of multidrug-resistant gram-negative bacilli infections (MDRGNI) in these patients is not well-described. Characteristics and predictors of MDRGNI in this population are presented.

Methods: Data from the Trauma Infectious Disease Outcomes Study of patients medevac’d through Landstuhl, Germany (LG) with transfer to a participating US hospital were assessed for infectious outcomes and microbial recovery. Using CDC criteria for infection and gram-negative bacilli defined as multidrug-resistant if they showed resistance to ≥3 of 4 antibiotic classes or were producers of extended spectrum β-lactamase or carbapenemases, data underwent post hoc time to event Cox proportional hazard analysis to assess factors associated with MDRGNI.

Results: A total of 913 patients (34% of 2699 trauma admissions) experienced ≥1 infection event (N=2210), of which 245 (27%) had a MDRGNI (24.6% of infections) with Escherichia coli (48.3%), Acinetobacter spp. (38.6%), and Klebsiella pneumoniae (8.4%) as the most common isolates. Median time to MDRGN event was 7 days with 75% of MDRGNI by day 13 post-trauma. MDRGNI patients had longer hospitalization (53 vs 38 days for non-MDRGN events; p-value <0.001). Increased MDRGNI risk was associated with injury severity score (ISS) ≥15 (RR: 10.6, 95% CI, 6.3-17.8). Factors associated with MDRGNI in restricted analysis for ISS ≥15 include: ISS≥25 (Hazard Ratio [HR]: 4.0, 95% CI, 2.6-6.0), amputation (HR: 3.0, 95% CI, 2.3-3.9), MDRGN colonization at LG (HR: 3.1, 95% CI, 2.3-4.3), and ventilator support at LG (HR: 1.9, 95% CI, 1.4-2.5). Antibiotic exposure assessed by class or in combination with duration administration out to 5 days was not significantly associated with increased risk for MDRGNI.

Conclusion: There is a high rate of MDRGNI in our cohort. Increasing severity of injury, limb amputation, MDRGN colonization, and ventilator support are associated with development of an MDRGNI. Further analysis is necessary to determine the impact of antibiotics on the risk for MDRGNI. These findings will assist providers when making preventive, treatment, and infection control decisions in the trauma patient population.

Wesley Campbell, MD, Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD, Ping Li, MS, Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, Timothy Whitman, DO, National Naval Medical Center, Bethesda, MD, Dana M. Blyth, M.D., San Antonio Military Medical Center, JBSA Fort Sam Houston, TX, Elizabeth Schnaubelt, MD, Landstuhl Regional Medical Center, Landstuhl, Germany, Katrin Mende, PhD, Infectious Disease Clinical Research Program, Uniformed Services University, Bethesda, MD and David R. Tribble, MD, DrPH, FIDSA, Infectious Disease Clinical Research Program (IDCRP), Uniformed Services University of the Health Sciences, Bethesda, MD

Disclosures:

W. Campbell, None

P. Li, None

T. Whitman, None

D. M. Blyth, None

E. Schnaubelt, None

K. Mende, None

D. R. Tribble, None

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