Converting from plastic surfaces could cut risk of HAIs, researchers argue.
Hospital beds with copper surfaces in an intensive care unit had significantly fewer bacteria than hospital beds with plastic surfaces, even after daily cleaning and disinfection, researchers found.
Active colony forming units per 100 cm2 on beds with copper rails, foot boards, and bed controls were less than 10% of those seen on conventional beds (median 42 vs 594), reported Michael Schmidt, PhD, of Medical University in South Carolina in Charleston, writing in Applied and Environmental Microbiology.
“The findings indicate that antimicrobial copper beds can assist infection control practitioners in their quest to keep healthcare surfaces hygienic between regular cleanings, thereby reducing the potential risk of transmitting bacteria associated with healthcare associated infections,” Schmidt said in a statement.
The authors explained that “metallic copper surfaces kill bacteria through a multi-modal mechanism through its ability to disrupt bacterial respiration, generate superoxide, and destroy genomic and plasmid DNA in situ.”
Studies have found that not only does environmental contamination play a role in transmitting pathogens responsible for healthcare-acquired infections, the investigators added, but copper-containing surfaces had reduced bacterial burdens.
Nevertheless, Schmidt noted, acute-care hospital beds on which all high-risk surfaces are copper have only recently become available.
“Based on the positive results of previous trials, we worked to get a fully encapsulated copper bed produced. We needed to convince manufacturers that the risk to undertake this effort was worthwhile,” he said.
This was a pragmatic cross-over study performed in a medical intensive care unit at a single medical center, which monitored the bacterial burden of control beds from April 2017 to July 2018, and interventional beds from April 2018 to March 2019 — noting a mixture of intervention and control beds from April to July 2018, as copper beds were introduced when a patient was discharged from a control bed.
Beds were thoroughly cleaned after patient discharge, and high-touch surfaces were routinely disinfected, as part of daily cleaning protocols, the authors said. Not surprisingly, they found that control beds accumulated higher concentrations of bacteria across all sampled areas, with the tops of the bed rails the most heavily soiled.
To put this into context, the authors noted that 89% of the samples collected from the control beds exceed the benchmark terminal cleaning and disinfection risk threshold compared to 9% from the copper beds, and 42% of copper beds were free of detectable bacteria.
In fact, the area with the heaviest bacterial burden on the copper bed was the internal, patient-facing surface of the foot board — though it was significantly lower than the comparative location on the control foot board, the authors noted.
One barrier to implementing this solution could be the cost of copper beds, but Schmidt and colleagues argued it would ultimately cost less than other adjunct cleaning options. Encapsulating a bed with antimicrobial copper would cost approximately $2,200 per bed, amortized over 5 years for a total of $1.20 per bed per day. The authors said that additional daily cleaning ($12-$13/room), ultraviolet radiation ($10/room), or hydrogen peroxide vapor phase deposition ($100/room) would be much more expensive.
“The copper intervention … is the only adjunct to act continuously, actively killing bacteria … and only adding a modest increase to the environmental services/infection control budget,” they wrote. “The value delivered by this intervention to the infection control bundle warrants further studies to assess its impact on HAI rates ultimately leading to consideration for its adoption.”