Low frequency of asymptomatic carriage of toxigenic Clostridium difficile in an acute care geriatric hospital: prospective cohort study in Switzerland

Daniela Pires, Virginie Prendki, Gesuele Renzi, Carolina Fankhauser, Valerie Sauvan, Benedikt Huttner, Jacques Schrenzel, Stephan Harbarth

The role of asymptomatic carriers of toxigenic Clostridium difficile (TCD) in nosocomial cross-transmission remains debatable. Moreover, its relevance in the elderly has been sparsely studied. To assess asymptomatic TCD carriage in an acute care geriatric population. We performed a prospective cohort study at the 296-bed geriatric hospital of the Geneva University Hospitals. We consecutively recruited all patients admitted to two 15-bed acute-care wards. Patients with C. difficile infection (CDI) or diarrhoea at admission were excluded. First bowel movement after admission and every two weeks thereafter were sampled. C. difficile toxin B gene was identified using real-time polymerase chain-reaction (BD MAX(TM)Cdiff). Asymptomatic TCD carriage was defined by the presence of the C. difficile toxin B gene without diarrhoea. A total of 102 patients were admitted between March and June 2015. Two patients were excluded. Among the 100 patients included in the study, 63 were hospitalized and 1 had CDI in the previous year, and 36 were exposed to systemic antibiotics within 90 days prior to admission. Overall, 199 stool samples were collected (median 2 per patient, IQR 1-3). Asymptomatic TCD carriage was identified in two patients (2 %). We found a low prevalence of asymptomatic TCD carriage in a geriatric population frequently exposed to antibiotics and healthcare. Our findings suggest that asymptomatic TCD carriage might contribute only marginally to nosocomial TCD cross-transmission in our and similar healthcare settings.