525Epidemiology and burden of recurrent Clostridium difficile infections

Background. Clostridium difficile infection (CDI) is associated with a 22% recurrence rate. However, few studies have focused on multiple recurrences. In order to evaluate the potential of new treatment options targeting specifically recurrences, we assessed the burden of recurrent Clostridium difficile infections (rCDI). Methods. A retrospective cohort of all adults diagnosed with CDI between 1998 and 2009, identified by a positive cytotoxin assay and ICD-9 CM/10 codes, living in the Sherbrooke area (Quebec, Canada). An rCDI was defined by the reappearance of diarrhea leading to a treatment, with or without a positive toxin assay or an endoscopic evidence of pseudomembranous colitis, within 14 to 60 days following the previous episode. Results. A total of 1311 patients were included (median age = 72.4 years; IQR = 54-82). Initial CDI was nosocomial in 35% of cases, followed a previous admission in 22%, and was community-acquired in 44%. The probability of having a first rCDI was 24% (291/1214) excluding deaths and total colectomies within 60 days, a second rCDI 41.3% (105/254), a third 33.3% (31/93), and a fourth or more 24.1% (7/29).