Vancomycin‐resistant Enterococcus faecium infection in patients with hematologic malignancy: patients with acute myeloid leukemia are at high‐risk

Abstract

Vancomycin-resistant enterococci (VRE) are significant nosocomial pathogens in patients with hematologic malignancy. Identification of risk factors for infection is necessary for targeted prevention and surveillance. An outbreak of VRE infection occurred at a tertiary cancer hospital between 1 August 2003 and 30 June 2005. Infection control measures recommended by the Society for Healthcare Epidemiology of America were used throughout the outbreak period. A matched case-control study was performed to identify risk factors for VRE infection. Fourteen VRE infections (13 episodes of bacteremia, one urinary tract infection) occurred a median of 10.5 d following hospital admission. All were due to Enterococcus faecium vanB. Univariate analysis identified the following variables to be significantly associated with VRE infection: presence of neutropenia, neutropenia >or=7 d, underlying diagnosis of acute myeloid leukemia (AML), and receipt of vancomycin, metronidazole or carbapenem antibiotic therapy in the 30 d prior to infection. On multivariate analysis, an underlying diagnosis of AML [odds ratio (OR), 15.00; P = 0.017] and vancomycin therapy during the previous 30 d (OR, 17.96; P = 0.036) were retained as independent risk factors for infection. Risk stratification for development of VRE infection is possible for patients with hematologic malignancy. Patients with AML represent a high-risk population, and targeted prevention strategies must include improved antibiotic stewardship, particularly judicious use of vancomycin therapy.