Risk factors for urinary tract infection caused by Enterobacteriaceae with extended-spectrum beta-lactamase resistance in patients admitted to internal medicine departments.

BACKGROUND Extended-spectrum beta-lactamase (ESBL) resistance is a growing concern in and outside hospitals. Physicians often face a true clinical dilemma when initiating empirical antibiotic treatment in patients admitted to internal medicine departments. OBJECTIVES To determine the prevalence of risk factors for ESBL resistance in patients with urinary tract infection (UTI) admitted to internal medicine departments. METHODS We conducted a retrospective analysis of the medical records of patients with UTI admitted to an internal medicine division in a community-based academic hospital over a 1 year period. We collected clinical, laboratory and imaging data that were available to the treating physician at admission. Outcome measures included ESBL resistance and death. RESULTS Of the 6754 admissions 366 patients were included in the study. Hospitalization during the previous 3 months (odds ratio 3.4, P < 0.0001), residency in a long-term-care facility (OR 2.4, P = 0.004), and the presence of a permanent urinary catheter (OR 2.2, P = 0.015) were correlated to ESBL resistance with statistical significance. These risk factors were extremely prevalent in our patient cohort. CONCLUSIONS ESBL resistance is becoming prevalent outside hospital settings, and patients admitted to an internal medicine department with UTI frequently carry risk factors for harboring resistant bacteria. In such patients a high index of suspicion and early targeted antibiotic treatment for ESBL-producing Enterobacteriaceae may be justified.