Impact of a new hospital with close to 100% single-occupancy rooms on environmental contamination and incidence of vancomycin-resistant Enterococcus faecium colonisation or infection: a genomic surveillance study

Vancomycin-resistant Enterococcus faecium (VRE) is a leading cause of nosocomial infection, driven by its ability to spread between patients and persist in the hospital environment. Here, we investigated the impact of a long-established cardiothoracic hospital moving to new premises with close to 100% single-occupancy rooms on the rates of environmental contamination and infection or colonisation by VRE. Prospective environmental surveillance for VRE was conducted at five time-points between April and November 2019, once in the original building, and four times in the new building. Flocked swabs (n=100/time-point) were used to sample bedspaces, bathrooms, computers and sluices in the critical care unit and the cardiothoracic ward. Environmental VRE was supplemented by clinical VRE isolates from the same time period, and underwent whole genome sequencing. Incidence rate ratios (IRR) of VRE infection/colonisation was determined for the one-year period before and after the hospital move, and compared to a nearby hospital. In the original location, the first environmental screen found 29% VRE positivity. The following four screens in the new location showed a significant reduction in positivity (1-6%, p