Risk Factor Analysis for Extended-Spectrum Beta-Lactamase Producing Enterobacterales Colonization or Infection: Evaluation of a Novel Approach to Assess Local Prevalence as a Risk Factor

Objective: To explore an approach to identify the risk of local prevalence of extended-spectrum beta-lactamase producing Enterobacterales (ESBL-E) on ESBL-E colonization or infection, and reassess known risk factors. Design: Case-control study. Setting: Johns Hopkins Health System emergency departments (EDs) in the Baltimore-Washington, D.C. region. Patients: Patients aged [≥]18 years with a culture growing Enterobacterales between 4/2019-12/2021. Cases had a culture growing an ESBL-E. Methods: Addresses were linked to Census Block Groups and placed into communities using a clustering algorithm. Prevalence in each community was estimated by the proportion of ESBL-E among Enterobacterales isolates. Logistic regression was used to determine risk factors for ESBL-E colonization or infection. Results: ESBL-E were detected in 1167 of 11,229 patients (10.4%). Risk factors included a history of ESBL-E in the prior year (OR, 15.62; 95% CI, 11.25-21.68), and exposure to a skilled nursing or long term care facility (OR, 1.66; 95% CI, 1.39-1.99), 3rd generation cephalosporin (OR, 1.83; 95% CI, 1.50-2.23), carbapenem (OR, 2.01; 95% CI, 1.46-2.78) or trimethoprim-sulfamethoxazole (OR, 1.53; 95% CI, 1.05-2.22) within the prior 6 months. Patients were at lower risk if their community had a prevalence <25th percentile in the prior 3 months (OR, 0.84; 95% CI, 0.71-0.98), 6 months (OR, 0.84; 95% CI, 0.71-0.99) or 12 months (OR, 0.81; 95% CI, 0.69-0.96). There was no association between being in a community >75th percentile and the outcome. Conclusions: This method of defining the recent local prevalence of ESBL-E may partially capture differences in the likelihood of a patient having an ESBL-E.