Hospital-acquired infections are a huge problem in the United States. Wouldn’t it be amazing if they could be prevented merely through the materials used in the hospital room?
Researchers at the Medical University of South Carolina explored covering key surfaces in hospital intensive care units in copper alloy, and found that this is an effective measure against the spread of some key types of bacterial infections. Their study is published in the journal Infection Control and Hospital Epidemiology.
Up to $45 billion a year is spent on health care costs related to hospital-acquired infections, and an estimated 100,000 deaths occur annually because of them, the study authors wrote.
The antimicrobial properties of copper have been known for hundreds of years, said Michael Schmidt, the study’s senior author – for at least 4,500 years. Ancient Indians realized that if water sits in a copper pot, this prevents illness, because the copper kills the bacteria. It’s not used as often nowadays because molded plastics and stainless steel have taken over, being easy and in expensive.
How does it work? Copper is used to transmit electrons in walls for electricity. Similarly, bacteria will donate electrons to the copper metal, which places the organism in an electrical deficit. As a consequence, free radicals are generated inside the cell. The cell’s proteins essentially get bleached, and its DNA get fractured. The electrical potential of the cell also gets collapsed.
“It’s pretty hard to develop resistance from that multi-hit mechanism of action,” Schmidt said.
How they did it
The study authors conducted the trial in the intensive care units of three different hospitals. Patients were randomly placed in copper or non-copper rooms. The study took place between July 2010 and June 2011.
Copper is an expensive material, so researchers carefully chose which parts of the ICU room should have the coating, based on the likelihood of a patient, staff member or visitor touching it. These included the rails that the patient uses to lift himself or herself out of bed, chair arms, the IV pole, the remote control and the tray that’s used over the bed. On the whole, copper surfaces covered less than 10% of the room in the settings used in this study.
The researchers were most interested in the spread of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). They compared the rates of hospital-acquired infections from any cause, or colonization with one of these two types of bacteria in the patients. Colonization means the bacteria is present on the person – such as on the skin, respiratory tract or gastrointestinal tract – without signs or symptoms of infection, said lead study author Dr. Cassandra Salgado.
Rooms with copper alloy surfaces were associated with lower infection and colonization for both of these types of bacteria than in normal ICU rooms. For hospital acquired infections, the rate was lowered from 0.081 to 0.034.
The challenge, of course, is investing the capital into buying new furniture and equipment for ICU rooms, Schmidt said. But he calculates that the cost of outfitting a room in this way would be recovered, in terms of money saved from preventing infections, after three months.
The researchers did not look at whether this intervention affects a patient’s 30-day readmission rate, or whether it would work in a hospital room that’s not part of an ICU.
Other researchers are looking at whether copper also stops carbapenem-resistant Enterobacteriaceae (CRE), a deadly, antibiotic-resistant strain of bacteria, Schmidt said.
“Bacteria have sex so quickly among their friends in their hospital environment, it may actually reduce the spread of CRE and other multi-drug resistant microbes, simply because the DNA is fractured,” Schmidt said.
Some of the study authors reported financial connections to the Copper Development Industry, which is the market development, engineering and information services arm of the copper industry.
But this isn’t the only research team that’s looking into this question. A separate group at the University of California, Los Angeles, received a $2.5 million federal grant in 2012 to study the germ-fighting effectiveness of copper in hospitals. The cost effectiveness of that is still unclear, said Dr. Daniel Uslan, director of the antimicrobial stewardship program at UCLA’s Geffen School of Medicine.
“I suspect the costs will be favorable, but more data is needed and I hope our study at UCLA will answer this important question,” he said in an e-mail. “We also don’t yet know which surfaces in a room are most critical. Can you get by with just coating one or two items, or do all the touch surfaces need to be copper coated? Obviously the costs will change dramatically depending on the number of surfaces coated.”