LAUSR

Complicated urinary tract infection (cUTI) is a common emergency department (ED) diagnosis. Results of urine culture and antimicrobial susceptibility testing are usually not available for up to 48 hours after an ED visit; therefore, diagnosis and treatment decisions are empiric and based on symptoms, physical findings, and underlying risk of resistance. We sought to understand the epidemiology and incidence of resistance to commonly used oral antibiotics among patients presenting to US EDs with cUTI. A retrospective multi-center study using data from the Premier Healthcare Database (2013-18) was performed. Inclusion criteria: (1) age ≥ 18 years, (2) primary cUTI ED/inpatient discharge diagnosis, (3) positive blood or urine culture between index ED service days -5 to +2. Transfers from acute care facilities were excluded. We examined rates of resistance to the following drugs/classes: 3rd generation cephalosporins, fluoroquinolones, trimethoprim-sulfamethoxazole, fosfomycin, and nitrofurantoin in patients presenting to the ED, stratified by those who were ultimately admitted as inpatients vs. not. Regional variation by US Census Division was examined. 187,789 patients met inclusion criteria; 119,668 (63.7%) were admitted to the hospital. 4.6% had positive cultures only with gram-positive bacteria; the remainder had at least one gram-negative pathogen. E. coli was the most common infecting pathogen, present in 72.1% of ED-only infections and 51.4% of those admitted. 44.7% and 58.4% of ED-only and admitted patients, respectively, were resistant to at least 1 of the 5 drugs/classes examined (see table). We saw substantial regional variation; resistance to at least 3 of 5 drugs/classes across all patients ranged from 5.0% in West North Central region to 11.1% in East South Central region (national average: 9.1%). Resistance Rates by Drug/Drug Class and Hospital Admission Status Patients with cUTI infections presenting to EDs in the US are frequently resistant to many commonly used oral antibiotics, even in patients not admitted to the hospital. Local epidemiology and resistance should be considered when making empiric treatment decisions in the ED. New oral options for cUTI patients are needed to address the growing challenge of resistance. Thomas Lodise, PharmD, PhD, Paratek Pharmaceuticals, Inc. (Consultant) Teena Chopra, MD, MPH, Spero Therapeutics (Consultant, Advisor or Review Panel member) Brian Nathanson, PhD, Spero Therapeutics (Independent Contractor) Katherine Sulham, MPH, Spero Therapeutics (Independent Contractor)