841. Implications of C. difficile Treatment on Environmental Contamination: A Randomized Controlled Trial with Microbiologic, Environmental, and Molecular Outcomes

BACKGROUND: Clostridioides difficile is a leading cause of healthcare-associated infection. Despite multimodal prevention efforts, in-hospital transmission continues to occur. In this study, we tested whether the choice of treatment can reduce C. difficile shedding and contamination of the inpatient environment. METHODS: We conducted a prospective, unblinded, randomized controlled trial of adult inpatients with C. difficile at Duke University Hospital. Thirty subjects were randomized 1:1:1 to receive metronidazole, vancomycin, or fidaxomicin. Stool specimens and environmental samples from five high-touch surfaces were serially collected throughout each subject’s hospital stay. Each specimen was assessed by quantitative culture and PCR ribotyping. Primary outcomes included the change over time in C. difficile stool burden and environmental contamination relative to treatment choice. As a secondary outcome, we examined the correlation between infecting strains and contaminating strains present in the care environment. RESULTS: Relative to metronidazole (Figure 1), C. difficile stool shedding decreased more rapidly for patients receiving vancomycin (P = 0.05) and most rapidly with fidaxomicin (P = 0.002). Treatment choice had no significant effect on total C. difficile colony counts across sites sampled over time (Figure 2). However, both vancomycin (P = 0.001) and fidaxomicin (P = 0.01) were associated with lower proportions of positive environmental cultures than metronidazole (Figure 3). Ribotyping of subjects’ stool isolates matched surrounding environmental isolates >90% of the time (Figure 4). CONCLUSION: Fidaxomicin and vancomycin reduced C. difficile stool burden more rapidly than metronidazole. Environmental results were mixed: fidaxomicin and vancomycin were associated with fewer positive surface cultures, but no difference in total colony counts. High concordance between stool and environmental ribotypes confirms that most room contamination originated from study subjects, without a significant contribution from any additional sources. Treatment choice may have a role in reducing C. difficile contamination of the hospital environment. Further study is needed to assess for effect on disease incidence. [Image: see text] [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: All Authors: No reported Disclosures.