Evaluation of the treatment of vancomycin-resistant enterococcal urinary tract infections in a large academic medical center

Abstract

Background: Vancomycin-resistant enterococci (VRE) are a common cause of nosocomial urinary tract infections (UTIs) among hospitalized patients. Clinicians need to differentiate between VRE-associated urinary colonization, asymptomatic bacteriuria, and UTIs to determine the need for treatment and length of therapy.

Objective: To characterize the diagnosis and management of VRE from urinary sources, including compliance with institutional treatment guidelines, and identify risk factors associated with clinical failure.

Methods: We performed a retrospective, single-center, cohort study among patients with VRE-positive cultures from urinary sources over a 3-year study period (July 2008-September 2011). Descriptive statistics were used to evaluate demographics, diagnostics, guideline compliance, pharmacotherapy, and outcomes. Risk factors associated with clinical failure were identified by multivariate logistic regression analysis.

Results: Two hundred sixty-nine distinct episodes of VRE met inclusion criteria among 252 patients. Forty-seven percent and 77% of episodes occurred in patients admitted to an intensive care unit and hospitalized for 7 or more days, respectively. Fifty-eight percent of the episodes were classified as asymptomatic bacteriuria or colonization. Compliance with institutional treatment guidelines for the appropriate drug, dose, and duration occurred in approximately 70% of the cases. Among noncompliant cases (n = 83), 48 (58%) were overtreated, and 35 (42%) were undertreated. Clinical failure among all cases was common, including mortality (17.1%). Factors independently associated with clinical failure determined on multivariate analysis included weight 100 kg or more (OR 5.30; 95% CI 1.42-12.21; p = 0.014), renal disease (OR 2.57; 95% CI 1.02-6.47; p = 0.048), indwelling catheter (OR 4.62; 95% CI 1.05-18.24; p = 0.046), and VRE bloodstream infection (OR 15.71; 95% CI 2.9-128.7; p < 0 .001).

Conclusions: Improved education is needed to minimize cases of overtreatment and undertreatment of VRE-associated UTIs and decrease inappropriate drug-related costs and clinical failure rates. Risk factors for clinical failure can be used to risk stratify VRE-associated UTIs and further guide treatment decisions.