Case–control Study Evaluating Risk Factors and Treatment Outcomes for Community-Acquired Urinary Tract Infections (UTI) Caused by Extended-Spectrum Β-Lactamase (ESBL)-Producing Pathogens

BACKGROUND: Community-acquired (CA) infections caused by ESBL-producing pathogens are becoming more common. Risk factors (RFs) for CA ESBLs have not been as extensively studied and remain relatively undefined. Recognition of patient-specific RFs for CA ESBL infections such as UTI can potentially improve patient outcomes through selection of more appropriate initial drug therapy. The objectives of this study were to identify RFs and associated treatment outcomes for CA UTI involving ESBLs. METHODS: Adult patients with CA ESBL UTI (cystitis) seen in the Emergency Department (ED) from 2009 through 2013 were retrospectively matched 1:1 with a control group of non-ESBL CA UTI based on age within 5 years, gender, and organism. The primary outcome was identification of RFs predictive of CA ESBL UTI. Secondary outcomes included comparison of ESBLs and controls in risk of inappropriate initial antibiotic therapy and need for additional follow-up to healthcare facilities (clinics, ED) within 14 days of initial treatment. RESULTS: Eighty-five patients were matched into each group. Compared with controls, CA ESBL UTI was associated with nursing home stay (P = 0.04), congestive heart failure (CHF, P = 0.04), hospitalization within the previous year (P = 0.04), and receipt of either any antibiotics or specifically, fluoroquinolones within the previous 3 months (P < 0.01 for both) by univariate analysis. Multivariate logistic regression identified hospitalization within 1 year (OR 3.8, 95% CI 1.7–8.7; P < 0.001), antibiotics within 3 months (OR 3.5, 95% CI 1.7–7.6; P < 0.001), and CHF (OR 4.9, 95% CI 1.3–24.7; P = 0.02) as significant RFs for ESBL CA UTI. Patients with CA ESBL infections were more likely to receive inappropriate initial antibiotics (OR 8.9, 95% CI 4.2–18.6; P < 0.0001) and, if treated inappropriately, to require repeat visits to healthcare facilities within 14 days (OR 11.4, 95% CI 2.6–50.8). CONCLUSION: Previous hospitalization, previous antibiotics, and CHF were RFs associated with CA ESBL UTI. These patients were significantly more likely to be treated inappropriately and to require additional healthcare follow-up. Recognition of RFs for CA ESBL UTI may facilitate appropriate ED-based management and avoid additional resource utilization. DISCLOSURES: D. N. Fish, Merck & Co.: Grant Investigator, Research grant M. Barron, Merck & Co.: Grant Investigator, Research grant