Copper Surfaces in Hospitals Help Wipe Out Bacteria

Hospitals have studied various new approaches to reducing the transmission of healthcare-associated infections, such as isolating carriers of Clostridium difficille (C. difficile) and using ultraviolet light to disinfect patient rooms. Now, a new study shows that using antimicrobial copper can kill surface bacteria and minimize pathogens in hospital rooms.

The high toll of healthcare-associated infections has made them a public health concern. According to the Centers for Disease Control and Prevention, patients picked up 721,800 infections in acute care hospitals in the United States in 2011. Of those, 75,000 patients with these infections died during their hospital stays. Two of the main causes of these infections include C. difficile and Methicillin-resistant Staphylococcus aureus (MRSA) bacteria, which are increasingly antibiotic-resistant and considered some of the biggest threats in hospitals today. Along with health consequences and life-threatening risks, a JAMA Internal Medicine study found that healthcare-acquired infections create $9.8 billion in excess medical costs each year.

A group of researchers from Grinnell College and the Medical University of South Carolina conducted a study focused on the way pathogenic microorganisms persist on high-touch surfaces in hospitals, helping to perpetuate the problem of healthcare-acquired infections. Their findings were recently published in American Journal of Infection Control. Even with rigorous cleaning and disinfection, the authors note that bacteria such as C. difficile spores can be hard to eradicate and easily repopulate. The research team sought to assess the use of copper alloy, known to have quick-acting antimicrobial properties, as a replacement in several high-touch surfaces. With research showing the in vivo and in vitro effectiveness of copper alloys in killing bacterial, viral, and fungal pathogens, this approach uses the natural properties of the metal with no side effect to patients.

“Due to the rise in antibiotic resistance and our decreasing arsenal of antibiotics able to treat infections, it is essential that we continue to investigate and test other methods for infection prevention,” says study author Shannon Hinsa-Leasure, PhD. “We need to reduce the exposure of patients to other pathogenic organisms and thereby reduce hospital acquired infections. Hospital acquired infections already strike approximately 1 in 25 patients and in 2011 an estimated 10% of those patients died. We can no longer rely on antibiotics alone.”

The researchers conducted the study in a 49-bed rural hospital, swapping out frequently touched metal, plastic, and porcelain surfaces and fixtures with copper alloy replacements. Items such as toilet flush handles, light switches, soap dispenser push plates, door levers, faucet handles, and sinks in patient rooms, en-suite bathrooms, and staff lounges were included in the study and given copper replacement parts. When the researchers compared the bacterial composition of the original surfaces — which routinely had bacterial levels exceeding recommended concentrations even after room cleaning – to the new copper surfaces, they noted a marked decrease in the concentration of viable bacteria, measured in colony-forming units (CFU). Measurements taken from the original surfaces showed an average concentration of 5,438 CFU/100 cm2, while the average concentration on the copper components was 117 CFU/100 cm2. Furthermore, 88% of the samples the researchers collected from copper parts in occupied areas showed concentrations below the levels recommended after cleaning, which is 250 CFU/100 cm2.

Their findings from this study showed the researchers that copper components helped keep bacterial concentrations low on highly-used surfaces. Furthermore, when combined with hand hygiene and proper room cleaning, they found that copper surfaces can play a key role in keeping healthcare-acquired infections low in hospitals.

“We did not test the effectiveness of copper against specific organisms in this study,” explains Dr. Hinsa-Leasure. “We looked at overall aerobic bacterial loads. There are numerous published papers demonstrating the ability of copper alloys to kill bacteria, viruses and fungi, and copper alloys are EPA certified against many types of organisms.”