If the dire predictions prove correct, we may be heading toward an infectious catastrophe. Unless, that is, the humble metal we count on to carry water and electricity into our lives can deliver in an even bigger way
BY PLAMEN PETKOV AND BRYAN SMITH
In 2002, Michels secured funding to conduct tests in the laboratory of Bill Keevil, Ph.D., an environmental microbiologist at the University of Southampton. The results, Michels says, were “very positive” and led to additional testing.
In 2007, that quest for answers launched a four-year clinical trial funded by the U.S. Department of Defense. “Our curiosity came out of the idea that perhaps medical and health care environments contributed in some way to the proliferation and persistence of pathogenic bacteria and microbes,” says Joseph F. John Jr., M.D., an infectious-diseases specialist at the Ralph H. Johnson VA Medical Center in Charleston, South Carolina, and a member of the research team. “So we started to wonder about surfaces.”
Researchers ran their tests in three ICU units at three U.S. medical centers—the Medical University of South Carolina, Memorial Sloan-Kettering Cancer Center, and the Ralph H. Johnson VA Medical Center. “We used very modest amounts of copper,” says Schmidt, who led the study. “It didn’t look like we dipped the room in a vat of molten copper.”
Instead, scientists covered six surfaces in eight ICU rooms at the medical centers: bed rails, the “overbed” tray tables patients use for meals, the arms of visitors’ chairs, IV poles, computer mouses, and the nurse call button used by patients. For the next three and a half years, the researchers sampled the microbial levels on those surfaces.
“We had no idea what to expect,” Schmidt says. “We were asking ourselves, ‘Will it work?’”
The answer was an unqualified yes. In fact, the findings were almost statistically too good to be true: Copper surfaces retained 96.8 percent fewer antibiotic-resistant bacteria than did wood, plastic, painted, or other metal surfaces.
As remote as it is, Calama may seem like an odd place for a world-class research project. It certainly did to me after a two-hour flight from Santiago and a dusty ride through the vast desert plain. The site looks more like a moonscape than a place scientists would tap for crucial corroborating evidence of copper’s CRE-slaying capabilities.
It made more sense when Huerta, my guide, and Marco Crestto, M.D., an administrator at the Copper Hospital, reminded me that the bulk of the hospital’s patients were miners from Chuqui, just down the road, and other Codelco mines. Who better to reap the potential benefits of copper than those who have devoted their lives to excavating it?
Nevertheless, Dr. Crestto told me, the head of the hospital was skeptical when he was first approached. He insisted that the most effective way to reduce infections was through old-school protocols, such as hand washing and surface cleaning. When Schmidt began explaining the wonders of the early findings, the director relented. And once the hospital was in, it was all in. Working in conjunction with the University of Chile in Santiago, Codelco researchers installed nearly 1,000 copper surfaces in 100 rooms in three hospitals.
When they heard of the study, the people of Calama were thrilled, Dr. Crestto says. “Every one of the patients said, ‘I really support this because if it prevents infections, it means I can go back to work faster and provide for my family, and my kids can go to school.’” For obvious reasons, they had a sense of pride, he says. “The people are very identified with copper.”
The metal didn’t disappoint: Results revealed that the pathogenic bacterial load was 90 percent lower on surfaces fitted with copper than it was in control rooms where the metal hadn’t been installed.
With the results in Chile echoing their promising findings, the scientists at the South Carolina and New York medical centers conducted a study to tackle the next and most obvious question: If copper was so effective at killing bacteria, would that translate into fewer patient infections? The answer: Copper surfaces slashed the number of health care–associated infections in ICU units by nearly 60 percent, according to findings published last May in the journal Infection Control and Hospital Epidemiology.
“That’s a big number,” says Schmidt. “We were surprised at how big. Nothing we know of has come close to being that effective. Most importantly, it confirmed what we had hoped: that by simply reducing the number of CRE and MRSA on frequently touched surfaces, we were able to cut the number of HAIs dramatically.”
Back in the halls of the Copper Hospital, copper has continued to prove itself to be the facility’s most precious metal. “In many hospitals you see higher infection rates,” Dr. Crestto says. “Here the rates have been stable for years and we don’t have to resort to using the newest antibiotics.”
But how can a seemingly inert substance that has no obvious antibacterial properties accomplish what disinfection and drugs can’t?
Copper is believed to be a sort of kryptonite to CRE and other pathogenic bugs—any contact the germs have with the metal spells an immediate weakening, followed by death. First, the CRE’s outer membrane ruptures. Through that rupture oozes vital nutrients and water, quickly sapping the cell’s strength. As a result, that which moments earlier was a “superbug” has turned into a mortally wounded weakling.
This initial damage occurs quickly—too quickly for the cell to recover and try to repair its damaged membrane or to multiply by transferring its resistance, researchers say. The kill shot quickly follows.
“It forces the bacterium to make free radicals, so it’s literally committing suicide when it’s exposed to copper,” says Schmidt. “The DNA is destroyed, and if there’s no DNA, there’s no life.”
Chile cherishes its copper. I can’t turn a corner without catching a shiny glimpse of it. In Calama, copper pillars greet guests in the lobby of the Sonesta Hotel. In Santiago, gift shop windows along the Plaza de Armas glimmer with copper trinkets. At the Santiago Bueras metro station, 400 meters of copper railing provide riders with a bacteria-free helping hand, thanks to the government. The pediatric hospital, Roberto del Rio, has outfitted 18 ICUs with copper bed rails, bed lever handles, nursery stations, doorknobs, push plates, sinks, and faucets—partly for another study, yes, but also to protect the city’s children from CRE and other lurking infections.
Elsewhere, in countries from Spain to South Africa, researchers are working to broaden and deepen the body of research. UCLA’s Dr. Uslan, for example, is helming a study that seeks to replicate the results of previous clinical trials and also to determine whether use of the metal on a widespread basis is cost-effective. To do so, a research team is targeting the school’s liver transplant unit and medical ICU.
“UCLA has some of the more complicated patients in the world because we have a very high-volume organ transplant program here,” Dr. Uslan explains. “Those patients are most susceptible to infection.
“We need to see how effective copper is. But we also need to tease out what’s really important to coat and what the highest impact surfaces would be,” he says. “And what I mean by that is, do you coat everything in copper? Do you make the walls and floors copper? Or are there certain things that give you the most bang for the buck?”