Fig. 4: Environmental detection of transmission clusters in the NICU.

aTemporal distribution of isolate sampling (red dot: invasive, blue dot: colonizing, gray diamond: environmental, numbers within circles indicate de-identified patient IDs, and text within diamonds indicates environmental sampling location), demonstrating the prolonged persistence of environmental reservoirs, demonstrating the detection of environmental isolates after the most recent detection of clusters. b Spatial mapping of environmental reservoirs (gray squares) relative to patient movement within the clusters, showing high spatial proximity between environmental isolate collection sites and patient bed locations. Environmental detection may represent persistent reservoirs or shedding from colonized patients, healthcare workers, or visitors.