2390. Acquisition of Clostridium difficile Infection Following Exposure from Roommate Defined by Concordance on Genotyping

BACKGROUND: Observational studies have identified same room occupancy with a hospital-onset Clostridium difficile infection (HO-CDI) case as a risk factor for subsequent CDI diagnosis. Despite this, the risk remains poorly characterized in endemic settings. Furthermore, genotyping techniques have not been applied to examine concordance between infecting strains in index patients and exposed roommates who eventually develop CDI. The study seeks to quantify transmission of C. difficile from an index case to their roommates and identify if concordance was present among strain types by the application of multi-locus sequence typing (MLST). METHODS: Laboratory-identified cases of hospital onset C. difficile infection (CDI) from October 1, 2017 through March 31, 2018, were included in the study. Patients with HO-CDI are placed in private room once diagnosis is established. Roommates who were in the same room as cases for at least 24 hours prior to diagnosis, regardless of duration of overlap, were identified through of the hospital patient tracking database to establish spatial link. Next, all exposed roommates who developed CDI within 3 months after exposure (defined as date of CDI diagnosis of index case) were identified. Strain types of linked cases was examined by MLST. RESULTS: During the 6-month period, 279 cases of CDI were diagnosed. Of these cases, 156 were hospitalized at the time of diagnosis including 83 (53%) in a room with shared occupancy. These 83 patients had 109 roommates that met exposure criteria. Four (3.7%) roommates developed CDI over a 90-day follow-up period. None of the examined pairs were genetically concordant. CONCLUSION: Indirect patient to patient transmission of C. difficile from newly diagnosed CDI cases to roommates is not common despite the spatial proximity with shared occupancy. DISCLOSURES: All authors: No reported disclosures.