1018. Clinical Utility of Rectal Swabs as a Predictor of Vancomycin-Resistant Enterococcal Infections Requiring Antibiotic Treatment
Session: Poster Abstract Session: Stewardship: Implementing Programs
Friday, October 4, 2013
Room: The Moscone Center: Poster Hall C
Background: Vancomycin-resistant enterococcus (VRE) rectal swabs are used to identify patients colonized with this organism in order to designate appropriate contact precautions. Although there is a lack of evidence to demonstrate the ability of the VRE rectal swab to predict infection, some clinicians may use a positive result as supportive data to empirically cover for VRE infection.  This practice leads to initiation of broad spectrum agents without a clear indication.  The purpose of this study is to assess whether the result of a VRE rectal swab can positively and/or negatively predict the presence of VRE infection.

Methods: A prospective, observational study was conducted from November 2012 to March 2013 at a large academic medical center. Patients were eligible for enrollment if they were at least 18 years of age, were admitted to an intensive care unit and had received a VRE rectal swab upon admission.  Patients were excluded if they did not receive a VRE rectal swab or if they received an anti-infective agent with VRE activity in the 7 days prior to the VRE rectal swab.  Patients were followed for 30 days and only during their first admission to the hospital.  Infection was defined as at least 1 positive culture from blood or bile, or bacteruria (WBC>10^5) plus pyuria (>10 WBC/HPF).

Results: 541 patients were evaluated during this time period. 503 patients met inclusion criteria, of which, 447 had a negative VRE rectal swab and 56 had a positive VRE rectal swab. 25% [14/56] of patients developed VRE infection within the positive rectal swab group and 2% [8/447] of patients developed a VRE infection within the negative rectal swab group (p <0.01). The infections included 4 bacteremias, 17 UTIs, and 1 peritoneal infection. The positive and negative predictive values of the rectal swab were 25% and 98%, respectively.  The sensitivity and specificity of the rectal swab were 64% and 91%, respectively.

Conclusion: A negative VRE rectal swab is a useful predictor of a negative VRE clinical culture. The likelihood of a patient having a VRE infection with a positive VRE rectal swab is low, meanwhile, the probability of a negative VRE clinical isolate when the rectal swab is negative is very high.  A negative VRE rectal swab may be a tool to guide empiric antibiotic coverage and support deescalating antibiotics with VRE activity.

Niyati Vakil, PharmD1, Alexander Levine, PharmD2, Christopher Lyman, PharmD1, Hsin Lin, PharmD1, Kelly Newman, PharmD1, Daniel Yeh, MD3, David Hooper, MD4 and Christy Varughese, PharmD1, (1)Pharmacy, Massachusetts General Hosptial, Boston, MA, (2)Pharmacy, Massachusetts General Hospital, Boston, MA, (3)Surgery, Massachusetts General Hospital, Boston, MA, (4)Massachusetts General Hospital, Boston, MA


N. Vakil, None

A. Levine, None

C. Lyman, None

H. Lin, None

K. Newman, None

D. Yeh, None

D. Hooper, None

C. Varughese, None

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