Incidence and mortality associated with Clostridium difficile infection at a Japanese tertiary care center

Background: Although increases in Clostridium difficile infection (CDI) incidence and severity have been observed in numerous countries, the incidence of CDI in Japan remains unclear. The goal of this study was to determine the incidence and outcomes of CDI at a Japanese tertiary care center. Materials and methods: Retrospective cohort study in patients with CDI was conducted at a 550-bed, tertiary care, academic center in Sapporo, Japan from September 2010 through August 2012. CDI cases diagnosed by enzyme immunoassays were categorized per internationally recognized surveillance definitions. Data on demographic characteristics, medication exposures, CDI presentation, and CDI treatment were collected on all CDI cases. Factors associated with 30-day all-cause mortality after the completion of CDI treatment were also investigated. Results: There were 32,296 admissions and 350,074 patient-days from 22,863 patients during the study period; 126 patients were diagnosed with CDI. The median age of CDI case patients was 78 years. Healthcare facility-onset (HO) CDI accounted for 86.5% of CDI cases, with a HO-CDI incidence of 3.11 cases per 10,000 patient-days. Three patients underwent surgery for CDI (2.4%) and 19 patients (15%) died within a 30 days of completing CDI treatment. Factors independently associated with mortality were diabetes mellitus and shock at time of CDI diagnosis. Conclusions: The CDI incidence was lower than that typically reported from North American hospitals, but the proportion of patients requiring surgical therapy and dying within 30 days of CDI in non-outbreak settings was higher. More study is needed to determine why CDI incidence is low relative to CDI-associated outcomes in Japan.