Incidence of Antibiotic-Resistant Escherichia coli Bacteriuria According to Age and Location of Onset: A Population-Based Study From Olmsted County, Minnesota

Abstract

Objective: To better understand the epidemiology of drug-resistant Escherichia coli across health care and community settings. Patients and Methods:We conducted a population-based cohort study of the incidence of antibiotic-resistant E coli bacteriuria among different patient groups. All urine cultures with monomicrobial growth of E coli obtained from Olmsted County, Minnesota, residents from January 1, 2005, through December 31, 2009, were identified. The initial isolate per patient per year was included. Analyses were stratified by patient age and location of infection onset (ie, nosocomial, health care associated, and community associated). Results: We evaluated 5619 E coli isolates and the associated patients. During the study period, the incidence of drug-resistant bacteriuria did not change among children but increased significantly among adults of all ages, most markedly among elderly patients older than 80 years. In elderly patients, the incidence of bacteriuria with isolates resistant to fluoroquinolones increased from 464 to 1116 per 100,000 person-years (PϽ.001), and the incidence of bacteriuria with isolates resistant to fluoroquinolones plus trimethoprim-sulfamethoxazole increased from 274 to 512 per 100,000 person-years (PϽ.05). When analyzed by location of infection onset, incidence of bacteriuria with isolates resistant to trimethoprim-sulfamethoxazole, fluoroquinolones, trimethoprim-sulfamethoxazole plus fluoroquinolones, extended-spectrum cephalosporins, and more than 3 drug classes increased significantly among communityassociated but not among nosocomial or health care-associated cases. Conclusion: In this population-based study, the incidence of antibiotic-resistant E coli bacteriuria nearly doubled during the 5-year study period among elderly patients and those with community-associated isolates. These patient groups should be targets of interventions to slow the emergence and spread of antibiotic-resistant E coli.

Emergency Department Urinary Antibiograms Differ by Specific Patient Group

“…Other studies have observed reduced antimicrobial susceptibility in the inpatient compared to outpatient setting (15,16). Our finding of reduced CIP susceptibility in hospitalized patients at the time of initial presentation to the ED together with reduced CFZ susceptibility in the ED cohort versus the institutional antibiogram suggests that reduced susceptibility, as reflected in the latter instance, is not entirely explained by selective pressure in the inpatient setting, and that characteristics of patients requiring hospitalization are also contributing factors.…”

Overdiagnosis of Urinary Tract Infection and Underdiagnosis of Sexually Transmitted Infection in Adult Women Presenting to an Emergency Department

“…We believe the current clinical practice of empirical therapy for a suspected lower UTI (cystitis) without urine culture may be penny wise but pound foolish. Although there may be cost savings from not performing urine cultures, the costs of unnecessary antibiotic therapy and missed STI diagnoses may be greater, given concerns about increasing resistance in both uropathogens (25) and N. gonorrhoeae (26), adverse effects due to unnecessary antibiotic therapy, and the clinical and public health consequences of unrecognized and untreated STIs (risk of sexual partner infection, and increase risk of pelvic inflammatory disease, adhesions, ectopic pregnancy, infertility, and chronic pelvic pain). Until a more accurate rapid diagnostic test for UTI is available or a more accurate, well-validated, user-friendly clinical decision rule incorporating symptoms and UA results is available, increasing urine culture and STI testing and decreasing empirical therapy for a suspected UTI or STI in this population should be evaluated.…”

Urinary Tract Infection and Asymptomatic Bacteriuria in Older Adults

“…Healthcare providers often confuse asymptomatic bacteriuria (ASB), defined as bacteria in the urine without any symptoms, with UTI, and unnecessary antibiotic treatment of ASB in older adults is common [2]. In the United States, the prevalence of antimicrobial resistance in urinary organisms in the community is increasing [3–5]. Colonization with multidrug resistant organisms is high in nursing home settings, and these organisms spread to other settings along with the colonized patients [6].…”