It would be premature for a hospital to install copper based on this study if future studies confirm earlier results, then hospitals should seriously consider copper installations.
—James Pile, MD, FACP, SFHM, vice chair, department of hospital medicine, Cleveland Clinic
Hospital-acquired infections (HAIs) are on the rise despite efforts to decrease them. HAIs cause an estimated 100,000 deaths annually and account for up to $45 billion in health-care costs. Adding fuel to the fire, bacteria increasingly are becoming resistant to last-resort drugs. Despite this gloomy outlook, a recent study in Infection Control and Hospital Epidemiology shows that a material known for its antimicrobial properties for more than 4,000 years—copper—might be a light at the end of this darkening tunnel.1
Ancient Indians stored water in copper pots to prevent illness, says lead study author Cassandra D. Salgado, MD, associate professor of medicine, hospital epidemiologist, and medical director for infection prevention at the Medical University of South Carolina (MUSC) in Charleston. But copper rarely is used in that manner today because molded plastics and stainless steel are less expensive and easier to mass-produce.
Dr. Salgado explains that the antimicrobial effect of copper-alloy surfaces is a result of the metal stealing electrons from the bacteria when they come into contact with each other. “Once the bacteria donate the electrons to the copper metal, this places the organism into a state of electrical-charge deficit,” she says. “As a consequence, free radicals are generated inside the cell, which ultimately leads to the cell’s death.”
Copper-alloy surfaces kill 99.9% of bacteria in less than two hours, says Harold T. Michels, PhD, PE, senior vice president of technology and technical services for Copper Development Association Inc. in New York, who was a study author. On other surfaces, bacteria may live for multiple days or even months.
Unlike current methods used to decrease HAIs (i.e. hand-washing and sanitizing surfaces), copper components don’t require human intervention or compliance to be effective.
“It supplements what these other things can do; it’s in the background and it’s always working,” Michels says.
A study needs to be done on the cost-effectiveness of copper surfaces. Health economists estimate that if copper surfaces were incorporated into ICUs, after three to six months, those surfaces would pay for themselves. That is not a long time period. Hospitals need to understand that there will be upfront costs but that they will realize benefits downstream.
—Cassandra D. Salgado, MD, associate professor of medicine, hospital epidemiologist, medical director for infection prevention, Medical University of South Carolina, Charleston
To conduct the study, copper prototypes of items touched most frequently by patients, health-care providers, and visitors were made and placed in patient rooms located within ICUs. “We placed the copper around the patient [much like a defensive perimeter] to reduce the likelihood that the health-care worker or visitor would introduce the infectious agent to the patient,” says the study’s lead investigator, Michael Schmidt, PhD, a professor and vice chair of MUSC’s department of microbiology and immunology.
Then, bacterial loads were measured on each object. For every study room, there was a control room without copper objects. Researchers were most interested in methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). For a period of time, bacterial burdens were measured in both copper rooms and control rooms.
Results exceeded the researchers’ expectations. Although only 7% of the touch surfaces in each ICU were replaced with copper components, there were 58% fewer HAI cases. The rate of HAI and/or MRSA or VRE colonization in ICU rooms with copper-alloy surfaces was significantly lower than that in standard ICU rooms (0.071 versus 0.123). For HAIs only, the rate was reduced to 0.034 from 0.081.3