Epidemiologic trends in Clostridioides difficile infection among US emergency department patients, 2014-2024

Community-acquired Clostridioides difficile infection (CDI) represents an increasing proportion of cases in the United States, yet contemporary data describing epidemiology and management in the emergency department (ED) are limited. We evaluated national trends in CDI incidence, antibiotic treatment, and outpatient medication exposures among ED patients.

We conducted a retrospective cohort study using the TriNetX Global Collaborative Network (163 healthcare organizations). ED encounters with CDI from 2014 to 2024 were identified, with community-onset CDI defined as an ICD-10 code for CDI during the ED encounter, no hospitalization in the preceding 12 weeks, and no hospital admission from the index ED encounter. Incidence was calculated per 1,000 ED visits. Antibiotic treatment within 24 hours was assessed, and interrupted time series analyses evaluated prescribing changes following 2017 and 2021 IDSA/SHEA guideline updates. Ninety-day medication exposures were analyzed using age-stratified regression.

Among 38 million ED encounters, 149,217 CDI cases were identified. Incidence declined from 2.94 to 2.07 per 1,000 visits (-30%), with decreases among older adults but a 58.8% increase in patients aged 18-24. Metronidazole use declined from 66% to 30% yet remained common years after guideline changes. Vancomycin use increased (>80%), and fidaxomicin adoption accelerated after 2021 (P = .001). Outpatient antimicrobial and acid-suppressive exposures increased over time, particularly among adults ≥45 years.

Despite declining incidence, CDI is increasingly affecting younger adults. Persistent metronidazole use highlights ongoing gaps in ED antimicrobial stewardship and opportunities for improved guideline adherence.