Risk Factors for Clostridioides difficile Infection in Ulcerative Colitis: A Single-Center Case- Control Study

Objective To identify independent risk factors for Clostridioides difficile infection (CDI) in patients with ulcerative colitis (UC). Methods A retrospective case-control study was conducted at a tertiary hospital. Hospitalized UC patients diagnosed between January 2022 and December 2023 were included. Patients were categorized into a CDI-positive group (n = 35) and a CDI-negative control group (n = 154). CDI diagnosis followed a two-step algorithm (glutamate dehydrogenase [GDH] / toxin enzyme immunoassay [EIA] plus confirmatory toxin gene PCR). Independent risk factors were analyzed using Firth penalized logistic regression. Results In multivariate analysis, active disease state (adjusted odds ratio [aOR] = 0.01, 95% confidence interval [CI]: 0.00–0.07; P < 0.001) and prior CDI history (aOR = 4.86, 95% CI: 1.43–20.08; P = 0.011) were independent risk factors for CDI. Body mass index (BMI) at admission, recent antibiotic use, and 5-aminosalicylic acid (5-ASA) therapy showed no significant independent association. Conclusion UC patients with active disease or a prior CDI history are at high risk for CDI and warrant enhanced surveillance and targeted preventive measures.