Clinical outcomes of Clostridium difficile infection according to strain type. A prospective study in medical wards

To describe clinical characteristics and outcome of Clostridium difficile infection (CDI) patients in Internal Medicine, to identify ribotypes (RTs); to evaluate the association between RT and patient clinical characteristics and report outcome.

One year prospective cohort study. Clinical data, Barthel Index (BI) and outcomes were collected for all inpatients suffering from CDI (n = 148) in hospital wards in Northern Italy. 84 fecal samples were analysed for molecular typing.

12 RTs were identified, predominantly RT018 (42.9%, n = 36/84) and RT356/607 (40.5%, n = 34/84). Patients with dementia were more frequent among those infected by RT018 [55.6% (n = 20/36) vs. 32.4% (n = 11/34), p = 0.05]. The median BI score of patients with RT018 was lower than BI score of patients with RT356/607 [10 (IQR 0-32) vs. 15 (IQR 5-50), p = 0.06]. RT018 infection was associated to higher levels of C-reactive protein [7.2 mg/dl (IQR 4.1-14.7) vs. 4.0 mg/dl (IQR 2.2-6.8), p = 0.01] and white blood cells ≥15,000/dl [33.3% (n = 12/36) vs. 14.7% (n = 5/34) of patients, p = 0.07]. Higher mortality was noted among RT018 infected patients. We found a continuous mortality increase according to the ATLAS score.

Our results confirm that RT018 and RT356/607 are the two major RTs causing CDI in older patients with a high degree of disability in Northern Italy and RT018 is associated with more serious outcomes.