Factors associated with acquisition of vancomycin-resistant enterococci (VRE) in roommate contacts of patients colonized or infected with VRE in a tertiary care hospital.

OBJECTIVE: Most nosocomial acquistion of vancomycin-resistant enterococci (VRE) is due to cross-transmission. We sought to identify risk factors for acquisition of VRE by roommates of patients colonized or infected with VRE. DESIGN: Retrospective cohort study. SETTING: A 472-bed tertiary care teaching hospital. METHODS: All patients who shared a room with a patient colonized or infected with VRE at our hospital between January 1, 1999 and December 31, 2006 were identified. These roommates of VRE-positive patients were screened by rectal swab culture on days 2, 5, and 7 after the last exposure to the index patient. Chart reviews were performed to identify risk factors for VRE colonization in these roommates. RESULTS: Eighty-eight roommates of patients colonized or infected with VRE were identified. Of the 38 roommates with complete follow-up, 8 (21%) became colonized with VRE. These 8 roommates were older (median, 87.5 vs 62.5 years of age; P = .001), had longer duration of room exposure (median, 8.5 vs 4 days; P = .002), and were more likely to have a urinary catheter (odds ratio [OR], 16 [95% confidence interval {CI}, 1.7-152]; P = .005), an elevated serum creatinine level (OR, 17 [95% CI, 1.4-196]; P = .02), low serum albumin level (OR, 9.9 [95% CI, 1.3-113]; P = .01), and recent third-generation cephalosporin use (OR, 8.3 [95% CI, 1.5-47]; P = .02). CONCLUSION: Roommates of patients identified as colonized or infected with VRE are at substantial risk of becoming colonized, with the degree of risk increasing in older and more frail patients. VRE control programs should pay particular attention to such patients.