Risk factors for Clostridioides difficile infection caused by ribotype 027 strains in the Veterans Affairs Healthcare System: a matched case-control study.

Background: In case-control studies, a variety of factors have been associated with Clostridioides difficile infection (CDI) due to the epidemic ribotype 027 strain. However, many studies have been limited due to small sample size and inclusion of only one facility.

Methods: Using a nationwide cohort of hospitalized patients in the Veterans Affairs (VA) Healthcare System, we conducted a retrospective, 1:3 matched case-control study of patients with CDI due to the ribotype 027 strain versus non-027 strains from October 1, 2008, to September 30, 2020. Controls were matched to cases by health care facility and year of diagnosis. Multivariate logistic regression was used to identify risk factors for CDI due to the 027 strain.

Results: A total of 3,353 cases were matched to 10,059 controls in 84 VA facilities. CDI due to the ribotype 027 strain was independently associated with prior macrolide or fluoroquinolone exposure, decreased functional capability, methicillin-resistant Staphylococcus aureus nasal colonization, age >65 years, white blood cell count >11,000 cells/mm³, and serum albumin < 3.5 g/dl.

Conclusion: Antimicrobial stewardship interventions focused on fluoroquinolones and macrolides could be beneficial in reducing the risk for infection due to the ribotype 027 C. difficile strain. Several other factors could potentially be used to identify patients at increased risk for CDI due to the ribotype 027 strain, but further studies are needed to assess their utility in clinical settings.