Epidemiology of Clostridium difficile-associated disease in internal medicine wards in northern Italy.

Clostridium difficile-associated disease (CDAD) is a growing health care problem. Elderly patients with multiple comorbidities and repeated hospitalization are at high risk for developing the disease. Few data are available on epidemiology of CDAD in Italy and no studies have focused on CDAD burden in internal medicine wards. We retrospectively analysed all CDAD cases in four internal medicine wards of a city hospital in northern Italy and reviewed the medical records of patients who developed CDAD during hospitalization. We identified 146 newly acquired cases, yielding a cumulative incidence of 2.56 per 100 hospitalizations and an incidence rate of 23.3 per 10,000 patient-days. Main risk factors were advanced age and length of hospitalization. A high proportion of CDAD patients had several comorbidities and had been treated with more than one antibiotic. The incidence is among the highest previously reported, this may be due to the characteristics of patients admitted to internal medicine wards and to the wards per se. We conclude that efforts are needed to reduce CDAD's burden in this setting, paying attention to logistics, patients care and antibiotic use.