The epidemiology of Clostridium difficile infection (CDI) has changed with an increase in incidence and severity. CDI is a serious medical condition, associated with a substantial morbidity and mortality, as well as costs, particularly in recurrent cases. The aim of this study was to estimate the incidence and the rate of recurrence in two centers of Lyon University Hospital (LUH).

A 3-year prospective surveillance was implemented in two centers of LUH: Group (G)1 (Édouard-Herriot Hospital) and Group 2 (Louis-Pradel Hospital, Pierre-Wertheimer Hospital and Femme–Mère-Enfant Hospital). Children (patients<18 years) and adults hospitalized for a period less than 2 days were excluded. Microbiological confirmation of CDI was done using a 2-step algorithm: a combined immunochromatographic test of GDH and toxins (C. DIFF QUIK CHEK COMPLETE^®, Alere) coupled with PCR (GeneXpert^® Systems, Cepheid). PCR was only performed when the screening test was positive and the toxins were negative. Incidence was calculated as the number of CDI diagnosed per 1000 hospitalized patients (HP). The origin of acquisition and relapse were defined as recommended by the European and National guidelines.

Between 2015 and 2017, 349 CDI cases were included in this study (G1: 262 and G2: 70 patients). The mean incidence of CDI episodes progressively decreased from 0.94 in 2015 to 0.66 per 1000 HP in 2017 (decrease by 47%). CDI episodes mostly occurred in patients>65 years of age (61.6%). Men slightly outnumbered women (50.7% and 49.3% respectively). A total of 279 (79.9%) had received antibiotics within one month preceding the onset of diarrhea. Free toxins were detected in 172 episodes (49.3%) and 177 episodes (50.7%) were confirmed by PCR. Most of the episodes were healthcare-associated (79.9%). The remaining cases were community-acquired (17.2%) and unknown (2.9%). No outbreaks and/or epidemic strain 027 were observed in this study. Over the study period, relapse within 60 days after diagnosis was observed in 26 patients (7.4%) and two of them experienced multiple relapse (7.7%). A total of 331 patients (94.8%) were specifically treated for CDI. Monotherapy management included metronidazole (n=217, 65.6%), vancomycin alone (n=52, 15.7%), or fidaxomicin (n=5, 1.5%). A combination or sequential administrations of two or three of them were needed in 15.7% and 1.5%, respectively. The comparison between the 2 centers showed that patients in G1 were older (median of 74 vs. 67 years in G2, P<0.001) and women were more frequent than men (52.3% vs. 40.2%, P=0.05). The mean of incidence was significantly higher in G1 (0.96 vs. 0.44 per 1000 HP, P<10⁻³). However, the rate of healthcare-associated CDI was higher in G2 (87.4% vs. 77.5% in G1, P=0.07). A higher significant exposure to antibiotics before the onset of diarrhea was observed in G2 (89.7% vs. 76.7%, P=0.009). Conclusions Only limited CDI epidemiological data exist in France. A significantly decreasing incidence of CDI episodes over the study period was observed. This incidence was two times more frequent in G1, which can be related to the characteristics of hospitalized patients in this center and/or the density of diagnosis. The rate of relapse was lower than usually reported in the literature. However, a national prospective study is necessary to evaluate the actual rate of relapse in France. Active surveillance of CDI is required to obtain an accurate picture of the real dimensions of CDI and to prevent the nosocomial transmission.