P-293. Epidemiology of Extraintestinal Invasive <i>Escherichia coli</i> Infections in 9 U.S. Communities, 2023

Abstract Background Extraintestinal invasive Escherichia coli (iEC) is a leading cause of sepsis and hospitalization, but US surveillance for iEC has been frequently limited to multidrug-resistant (MDR) strains and hospitalized cohorts. To describe the incidence and clinical characteristics of MDR and non-MDR iEC and inform prevention and vaccine development, CDC’s Emerging Infections Program piloted active population- and laboratory-based surveillance in 9 US sites. Methods Among surveillance area residents ( &amp;gt; 7.3 million people), an incident iEC case was the first isolation of E. coli in a 30-day period from a normally sterile body site (June–August 2023). Demographic, clinical, and laboratory characteristics were assessed by chart review. Annual incidence rates by surveillance area were estimated by multiplying total case number by 4 and used 2022 US census data for denominators. Results Among 1345 iEC cases in 1334 patients, E. coli was isolated from blood in 1223 (90.9%) and from other sterile sites in 122 (9.1%). Median age was 68 years (IQR 55–79); 766 (57.0%) were female. Overall estimated annual crude incidence rate was 74.5 cases per 100,000 population (range by area 51.3–95.6) and was higher for persons aged ≥ 60 vs &amp;lt; 60 years (228.5 vs 30.4). Cases were most commonly community associated (554, 41.2%) or health care associated community onset (633, 47.1%). Most case-patients (1194, 88.8%) had comorbidities; diabetes was most common (457, 34.0%). Of all cases, 762 (56.7%) were associated with urinary tract infection (UTI), 192 (14.3%) with recurrent UTI, and 213 (15.8%) had a urinary catheter in the 2 days before collection of the iEC-defining specimen. Among 1160 hospitalized cases, median length of stay was 5 days (IQR 3–9), 103 (8.9%) died. Of reported E. coli susceptibilities, 144/500 (28.8%) were fluoroquinolone-resistant, 185/1345 (13.8%) were extended-spectrum β-lactamase producing, and 3/1345 (0.2%) carbapenem-resistant. Conclusion The burden of iEC disease was substantial compared to other invasive pathogens and primarily affected older adults. Over half of infections accompanied UTIs and involved hospitalization. Continued surveillance to monitor trends over time, inform vaccine development and evaluation, and advise prevention efforts are needed. Disclosures All Authors: No reported disclosures