2030. Daptomycin Nonsusceptible (DapNS) Vancomycin Resistant Enterococcus (VRE) Bloodstream Infections (BSI) in Patients (pt) with Hematologic Malignancies (HM): Risk Factors and Outcomes
Session: Poster Abstract Session: Antimicrobial Resistant Infections: Treatment
Saturday, October 29, 2016
Room: Poster Hall
Background: In HM pt, VRE BSI is associated with increased morbidity & mortality. Dap is typically used to treat VRE BSI, but the emergence of DapNS-VRE has been noted. Data regarding risk factors for BSI with DapNS-VRE are limited. We sought to determine risk factors and outcomes of DapNS-VRE BSI in our HM pt.

Methods: All HM pt with DapNS-VRE BSI between Jan. 2011 & Dec. 2015 were studied. Pt were matched 1:2 with control HM pt who had Dap-susceptible (DapS) VRE BSI based on disease, age & transplant status.

Results: A total of 19 DapNS-VRE BSI cases & 38 DapS-VRE BSI controls were included. Mean age was 56 years for cases and 60 for controls; Among the cases, 11 pt (58%) were male compared to 29 pt (76%) within the controls. 85% of cases and controls had AML. Five cases initially had DapS-VRE BSI & then developed DapNS-VRE on consecutive blood cultures. An additional 3 cases with DapS-VRE BSI had cleared their blood cultures, but within 7 days developed DapNS-VRE BSI. There were 6 additional cases who had a previous enterococcal infection within the prior 90 days. Ultimately, there were 9 cases (47%) vs. 2 controls (6%) with a previous enterococcal infection within the prior 90 days. Individual predictors for DapNS-VRE BSI were prior Dap exposure (p<.0001), prior enteroccocal infection <90 days (p=.001), prior cefepime exposure (p=.023), typhlitis (p=.021), & GI bleed (p=.038). Chemotherapy type, immunosuppression, and malignancy status (relapse vs. new diagnosis) were not associated with increased risk for DapNS-VRE BSI. Duration of BSI & mortality were similar in both groups.

Conclusion: Prior use of Dap and prior enterococcal infection were identified as highly significant risk factors for DapNS-VRE BSI. In a few HM pt, DapNS-VRE appeared to develop while on Dap which likely reflects selection for resistant organisms. Currently, treatment options for VRE BSI are limited. The association of DapNS-VRE with prior Dap exposure raises the question of whether Dap should be the first-line agent for VRE BSI in HM pt or whether, if used, higher doses could prevent the emergence of resistance.

Erica S. Herc, MD1, Bernard L. Marini, PharmD2, Anthony J. Perissinotti, PharmD2, Jose A. Diaz, MD3, Marisa H. Miceli, MD1 and Carol A. Kauffman, MD, FIDSA, FSHEA4, (1)Division of Infectious Diseases, University of Michigan, Ann Arbor, MI, (2)Pharmacy, University of Michigan, Ann Arbor, MI, (3)Vascular Surgery, University of Michigan, Ann Arbor, MI, (4)University of Michigan & Ann Arbor VA Healthcare System, Ann Arbor, MI

Disclosures:

E. S. Herc, None

B. L. Marini, None

A. J. Perissinotti, None

J. A. Diaz, None

M. H. Miceli, None

C. A. Kauffman, None

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