Role of Clostridioides difficile in hospital environment and healthcare workers.

Clostridioides difficile infection (CDI) was traditionally considered to be transmitted within healthcare environment, from other patients or healthcare workers (HCW). Recently, this idea has been challenged. Our objective was to determine the extent of C. difficile contamination in hospital environment with a simplified method for C. difficile recovery. Environmental samples were taken from rooms of patients positive for CDI (Case) and negative for toxigenic C. difficile (Control). Environmental sampling was performed at the time a fecal sample was taken for CDI diagnosis, 48h after, and 10 days after. HCW hands were also sampled. A total of 476 environmental samples were collected, 246 samples from "Case" rooms and 230 from "Control". Overall, 15.34% of environmental samples were positive for toxigenic C. difficile (TCD), 20.72% of "Case" rooms samples and 9.57% of the samples from "Control" rooms (p=0.001). When samples from "Case" rooms were analyzed by sampling time, at diagnosis 52.94% were positive, 38.46% were positive at 48h after symptom resolution and 23.07% were positive after course of treatment. Overall, the most contaminated site corresponded to the bathroom tap, followed by the toilet. We recovered TCD from alcohol-based dispensers and from 4.2% of HCW hands. We found a high proportion of surfaces contaminated with TCD, as well as hand colonization. Notably, even after isolation measures were terminated, there was still TCD contamination.