Screening of Clostridioides difficile carriers in an urban academic medical center: Understanding implications of disease

Objective: Efforts to reduce Clostridioides difficile infection (CDI) have targeted transmission from patients with symptomatic C. difficile. However, many patients with the C. difficile organism are carriers without symptoms who may serve as reservoirs for spread of infection and may be at risk for progression to symptomatic C. difficile. To estimate the prevalence of C. difficile carriage and determine the risk and speed of progression to symptomatic C. difficile among carriers, we established a pilot screening program in a large urban hospital. Design: Prospective cohort study. Setting: An 800-bed, tertiary-care, academic medical center in the Bronx, New York. Participants: A sample of admitted adults without diarrhea, with oversampling of nursing facility patients. Methods: Perirectal swabs were tested by polymerase chain reaction for C. difficile within 24 hours of admission, and patients were followed for progression to symptomatic C. difficile. Development of symptomatic C. difficile was compared among C. difficile carriers and noncarriers using a Cox proportional hazards model. Results: Of the 220 subjects, 21 (9.6%) were C. difficile carriers, including 10.2% of the nursing facility residents and 7.7% of the community residents (P = .60). Among the 21 C. difficile carriers, 8 (38.1%) progressed to symptomatic C. difficile, but only 4 (2.0%) of the 199 noncarriers progressed to symptomatic C. difficile (hazard ratio, 23.9; 95% CI, 7.2-79.6; P < .0001). Conclusions: Asymptomatic carriage of C. difficile is prevalent among admitted patients and confers a significant risk of progression to symptomatic CDI. Screening for asymptomatic carriers may represent an opportunity to reduce CDI.