Re-examining Novel Risk Factors for Community-Acquired Clostridioides difficile : A Multimodal Approach

Abstract Background Geospatial surveys have identified livestock operations as potential sources for community-acquired Clostridioides difficile infection. Confirmatory studies integrating individual-level risk factors, geospatial data, and environmental surveys are limited. Methods We conducted two parallel studies: 1) a case control assessment of C. difficile risk associated with livestock and 2) a microbiologic survey of surface waters and wastewater influent for C. difficile. For aim 1, adult residents of North Carolina tested for C. difficile through Duke University Health System from March 2020 to December 2025 were included. Tests sent after day 3 of hospitalization (presumed hospital-onset) were excluded. Multivariable logistic regression with generalized estimating equations was used to assess C. difficile risk associated with livestock operations while adjusting for age, comorbidities, antibiotic receipt, and hospital contact. For aim 2, samples collected from three surface water and two municipal wastewater sites in North Carolina from April 2022 to October 2023 were tested for C. difficile gene targets by quantitative polymerase chain reaction. Results The case-control cohort included 26,195 tests from 21,045 unique subjects, 3,835 (14.6%) of which were positive for C. difficile by nucleic acid amplification testing. Residence in the same watershed as commercial swine operations was associated with C. difficile risk (adjusted odds ratio 1.11, 95% CI 1.00-1.23, p=0.04). While C. difficile gene targets were ubiquitous in municipal wastewater, they were not detected in three regional surface waters. Conclusion Swine operations were associated with C. difficile risk even after adjustment for individual-level risk factors. C. difficile detection in water varies by source.