Severe Clostridium difficile infection: incidence and risk factors at a tertiary care university hospital in Vienna, Austria.

BACKGROUND: Clostridium difficile infection (CDI) is the major cause of hospital-acquired bacterial diarrhoea. The incidence of CDI has been increasing in Canada, the US and Europe and severe cases are becoming more common. METHODS: A retrospective cohort study investigating all patients with an episode of CDI present at the Vienna University Hospital between 01 January 2012 and 31 December 2012 was conducted. All microbiologically confirmed C. difficile toxin positive cases were included, ribotyped and analysed regarding their clinical course. RESULTS: A total of 278 patients with CDI were recorded, with an overall CDI incidence of 5.23 per 10,000 patients-days. Around 84,5 % (235/278) of CDI cases would have been classified as severe CDI according to European Society of Clinical Microbiology and Infectious Diseases (ESCMID) if all criteria were used. According to Society for Healthcare Epidemiology of America and the Infectious Diseases Society of America (SHEA/IDSA) guidelines only 16.5 % (46/278) could be classified as severe; with a severe CDI incidence of 4.41 and 0.86 per 10,000 patient-days, respectively. Multivariate analysis showed only a co-morbidity index of ≥ 3 (p = 0.013) as independent risk factor for severe CDI. No link between ribotype 027 and severity or clustering was observed in our study population. CONCLUSIONS: Special attention in terms of restrictive antibiotic prescription should be given to patients having a Charlson co-morbidity ≥ 3 at the time of hospital admission. SHEA/IDSA guidelines were more accurate than ESCMID criteria in predicting severe CDI in our collective, of mostly severely ill patients, in a tertiary care hospital setting.