Researchers in Africa find copper surfaces help to control drug-resistant superbug
A second study in as many months has thrown increased weight behind the efficacy of copper in fighting the spread of healthcare associated infections (HCAIs) in hospitals.
Last month, BBH reported how a research team at the Medical University of South Carolina in the United States had found that the use of heat exchangers fabricated from either antimicrobial copper or aluminium limited the growth of harmful bacteria in hospital heating, ventilation and air conditioning systems.
Now a second study conducted by the preventative medicine, microbiology and maintenance department of the University Hospital of Ceuta in North Africa has demonstrated copper’s efficacy against the drug-resistant bacteria, Imipenem-Resistant Ainetobacter Baumannii (IRAB). The superbug was chosen following a serious epidemic at the facility in 2009.
And the findings could have an impact on the wider issue of reducing the prevalence and spread of bugs more commonly found in UK healthcare environments, including MRSA, E.coli and C.difficile.
Dr Julián Manuel Domínguez, section chief for preventive medicine and public health at the hospital, who was the lead researcher for the study said: "In 2009, we had an epidemic outbreak of IRAB at our hospital and controlling it proved extremely complicated, especially since patients were arriving with the infection from other healthcare centres and passing it to other patients. We believe much of this transmission is likely to have occurred via touch surfaces.
"We decided to test the antibacterial efficacy of copper with the IRAB strain isolated during the hospital outbreak because of its high transmissibility and the very serious consequences for patients. It was especially devastating to patients undergoing surgery, the immunosuppressed and ICU patients. We needed an additional measure in place to protect vulnerable patients from infection."
The researchers assessed the survival time of IRAB on a stainless steel door handle in comparison with a brass door handle - brass being a copper alloy that benefits from its antimicrobial properties. Within seven minutes, IRAB had disappeared from the copper alloy - a six-log decrease in contamination - whereas growth persisted in all cultures on the stainless steel control. The full results, including further tests with E. coli bacteria, showed a similar outcome and are currently being written up for peer-reviewed publication.
Having demonstrated the copper alloy's rapid antibacterial effect, the next objective for researchers at the hospital will be to evaluate the efficacy of antimicrobial copper against environmental microbial contamination in a patient care environment.
The two recent studies follow similar efforts in the UK and Chile that have demonstrated the ability of antimicrobial copper to consistently reduce surface contamination by greater than 90%. The three-centre US trial also demonstrated a link between lower contamination on copper surfaces and reduced infection rates in intensive care patients, and further assessments are under way in Poland, France and Greece.
The findings have been welcomed by the Copper Development Association in the UK, where a spokesman said: “Around 80% of infectious diseases are transferred by touch and, while healthcare professionals employ strict infection control measures including handwashing and frequent surface disinfection, these measures are not enough.
“Frequently touched surfaces in intensive care units are heavily contaminated with anywhere from several hundred to more than 10,000 colony forming units of infectious bacteria. These surfaces are touched by patients, families, doctors, nurses, and cleaning staff and it is exactly here where an added line of defence is now available.
“Antimicrobial Copper touch surfaces kill the microbes that cause infections where they lie and are ideal for the healthcare environment, where their inherent, continuous ability to kill bacteria will supplement infection control measures.”