[Prevalence of Clostridium difficile infection in hospitalized patients with diarrhea: results of a French prospective multicenter bi-annual point prevalence study]

Background: Clostridium difficile infections represent the major cause of healthcare-associated diarrhea. The objective of the study was to determine the incidence of C. difficile infection (CDI) in 2012 and to assess the under-estimation of the disease in France.

Methods: Seventy healthcare facilities participated in a prospective point prevalence study. Each laboratory was requested to send all the diarrheal stool samples from hospitalized patients during 2 days (one in December 2012 and one in July 2013) to the National Reference Laboratory (NRL) for C. difficile, irrespective of a medical request for C. difficile. At the NRL, stool samples were analyzed using the Quik Chek Complete assay (Alere). Positive samples for glutamate deshydrogenase or toxins were confirmed by the toxigenic culture. Results obtained by the NRL were then compared to those given by each healthcare facility. Incidence of CDI in 2012 was provided by each healthcare facility through a specific questionnaire.

Results: Mean incidence of CDI reported in 2012 by the HCF was 3.6 ± 2.9 per 10,000 patient-days; the incidence was positively correlated to the density testing (defined by the number of tests per 10,000 patient-days), which varied across the HCF (median 29.0 per 10,000 patient-days, IQR 19-50). During the bi-annual point prevalence survey, 651 stool samples were included and 90 were positive for C. difficile in culture. The overall prevalence of patients infected by a toxigenic C. difficile strain was 9.7% (63/651) and the prevalence of patients colonized by a non-toxigenic strain was 4.2% (27/651). Among the 65 cases of CDI detected by the NRL, 35 (55.6%) were missed by the participating HCF because of a lack of sensitivity of the methods used for the diagnosis (16/63, 25.4%) or because of a lack of clinical suspicion (19/63, 30.2%).

Conclusion: The incidence of CDI in 2012 has increased in France compared to that of 2009 but is still underestimated because of a lack of clinical suspicion or a lack of sensitivity of methods used for toxin detection.