To evaluate the effect of copper-coated high-touch surfaces on environmental microbial burden and healthcare-associated infection (HAI) rates.

Observational cohort study over 20 months.

Pediatric intensive care and oncology inpatient units in a tertiary care hospital.

All patients admitted to rooms with or without copper-coated surfaces.

Spray-on copper coating applied to high-touch surfaces in patient rooms.

Patients were admitted to rooms according to routine hospital practices. Demographic and clinical data were collected for a subset of patients admitted to rooms with copper-coated surfaces and matching control rooms. Environmental samples were collected from high-touch surfaces to quantify bacterial colony counts. HAIs were identified via a surveillance database and reported per 10,000 patient days. Poisson regression and negative binomial mixed-effects model were used for analysis.

Patients in copper-coated rooms were more likely to have an infection on admission (29.7% vs 2.9%; P = .003). Bacterial colony counts trended lower in copper-coated rooms (rate ratio (RR) 0.74, 95% CI 0.50–1.08; P = .11; absolute rate difference −12.25, 95% CI −26.12–2.10), with variability by surface type. HAI rates trended higher in copper-coated rooms compared to control rooms (48.2 vs 30.5 per 10,000 patient days; RR 1.58, 95% CI 0.78–3.20; P = .20).

Copper-coated surfaces were not associated with statistically significant reductions in microbial burden or HAI rates. Contributing factors may include low baseline microbial load, low baseline HAI rates, variable copper alloy efficacy, short study duration, and differences between patients in intervention and control rooms.