Background: Studies have shown that patients colonized with highly resistant microorganisms (HRMO) contaminate the hospital environment, and that transmission from contaminated environments to patients occurs. In May 2018, the Erasmus MC University Medical Center, Rotterdam, moved from a hospital with mostly multiple-occupancy rooms to a new hospital with 100% single-patient rooms with private bathrooms. This move provided the unique opportunity to determine environmental contamination before the new hospital was open for admissions and thereafter and to compare the environmental contamination to the number of patients colonized with HRMO. Method: Environmental sampling took place twice in the old building and 12 times in the new building, from 2 weeks before to 15 months after relocating patients. At each moment, ~306 samples were taken from 13 locations (eg, nightstands, sinks) in 40 patient rooms. Samples were screened for Staphylococcus aureus (methicillin-susceptible [MSSA] and methicillin resistant [MRSA]) and highly resistant Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus faecium, and Enterobacteriales. During the study period, January 1, 2018, until August 31, 2019, all clinical samples positive for HRMO were included. Results: Environmental sampling revealed that 29 of 724 (4.0%) locations were positive for HRMO in the old building, whereas 4 of 3,358 (0.1%) samples in the new building were positive for HRMO (P < .001). In the old building, 14 of 29 locations were positive for extended-spectrum β-lactamase (ESBL)–producing bacteria and 15 were positive for carbapenemase-producing bacteria. In the new building, 3 of 4 positive samples were positive for vancomycin-resistant E. faecium (VRE), 1 was positive for ESBL-producing K. pneumoniae. For both HRMO, no carriers were detected. In the old building, 145 of 12,256 adult patients (1.2%) had clinical samples positive for HRMO, compared to 561 of 38,397 (1.5%) in the new building, a small but significant increase (P = .02). Conclusions: The transition from mainly 2- and 4-person rooms to 100% single-patient rooms resulted in a significant decrease in environmental contamination, even though the number of patients colonized with HRMO slightly increased. No molecular typing to determine transfer from environment to patients and vice versa has yet been performed. Future sampling is needed to determine whether the low environmental contamination is a long-term effect of the transition to single rooms.

Funding: None

Disclosures: None