Clinical Predictors of Recurrence After Primary Clostridioides difficile Infection: A Prospective Cohort Study.

Background: Recurrent Clostridioides difficile infection (CDI) is a major public health threat. While clinical prediction tools exist, they do not incorporate the newest Infectious Diseases Society of America guidelines.

Methods: This was a prospective longitudinal study of patients experiencing their first episode of uncomplicated CDI. Patients were followed from diagnosis through 8 weeks post-completion of their anti-CDI therapy to assess recurrence. Stool was collected at diagnosis and weekly for 8 weeks following treatment. Recurrence was defined as diarrhea as well as a positive stool test by toxin EIA (EIA) for C. difficile. Fisher's exact test for binary variables and Student's t test for continuous variables were performed. Cox regression was performed to assess for predictors of CDI recurrence.

Results: Seventy-five patients were enrolled between August 1, 2015, and September 1, 2018. Mean age 58.1 years ± 15.5, 69.3% female, 74.7% were white, 11.3% had baseline irritable bowel syndrome, and 54.7% were actively using PPIs. Over the 8-week follow-up period, 22 patients developed a confirmed CDI recurrence. Univariate predictors of recurrence included treatment with metronidazole (40.9% vs 15.1%, p = 0.03), initially diagnosis by EIA (77.3% vs 43.4%, p = 0.007) and platelet count (206 ± 72.1 vs 270.9 ± 114.8, p = 0.03). A Cox regression model revealed primary diagnosis by EIA (HR 3.39, 95% CI 1.23, 9.31, p = 0.018) and treatment with metronidazole (HR 3.27 95% CI 1.31-8.19, p = 0.01) remain predictors for CDI recurrence.

Conclusion: In a large prospective longitudinal cohort of uncomplicated CDI patients, treatment with metronidazole and diagnosis via EIA were the most robust predictors of CDI recurrence.