Effectiveness of Copper-Impregnated Solid Surfaces on Lowering Microbial Bio-Burden Levels in an Acute Care Hospital

Abstract

Background: Microbial bio-burden on high-touch surfaces in patient rooms may lead to acquisition of health care-associated infections in acute care hospitals. This study examined the effect of a novel copper-impregnated solid material (16%-20% copper oxide in a polymer-based resin) on bacterial contamination on high-touch surfaces in patient rooms in an acute care hospital.

Methods: Five high-touch surfaces were sampled for aerobic bacterial colonies (ABCs) 3 times per day over a 3-day period in 16 rooms with copper installed and 16 rooms with standard noncopper laminate installed on high-touch surfaces. A Bayesian multilevel negative binomial regression model was used to compare ABC plate counts from copper-impregnated surfaces with standard hospital laminate surfaces.

Results: The mean and median (interquartile range [IQR]) ABC counts from copper-impregnated surfaces were 25.5 and 11 (4-27), and for standard hospital laminate surfaces they were 60.5 and 29 (10-74.3). The negative binomial regression model-estimated incidence rate for ABC counts on plates taken from copper-impregnated surfaces was 0.40 (0.21-0.70) times the incidence rate of ABC counts on plates taken from standard hospital laminate surfaces.

Conclusions: Copper-impregnated solid surfaces may reduce the level of microbial contamination on high-touch surfaces in patient rooms in the acute care environment, as our study demonstrated a decline in microbial bio-burden on samples taken from copper-impregnated compared with standard hospital laminate high-touch surfaces.

Keywords: copper; health care–associated infection; microbial bio-burden; no-touch disinfection.

Figure 1.

Various copper-impregnated high-touch surfaces in our hospital; top left: sink; top right: tray table; bottom left: bedrails; and bottom right: foot rail.

Figure 2.

Boxplots of aerobic bacterial colony plate counts taken from control and copper surfaces for each sampled time over the 3-day period. Surfaces were disinfected at hour 0 and sampled at the hours shown in the plot. Actual data points (with horizontal jitter) overlay the boxplots. For visual clarity, the y-axis is restricted to 400 colonies; however, there were a few samples in the control group that exceeded this value and are thus not seen on the plot.