A Copper Alliance Member
Copper Could Help Contain Flu
January 30, 2006
FOR IMMEDIATE RELEASE
Copper could help prevent flu infections. Recent studies at the University of Southampton, U.K., show that Influenza A is virtually eradicated within six hours on copper surfaces. Influenza A viruses cause an average of 200,000 hospitalizations and 36,000 deaths a year in the USA, alone. The Influenza A family of viruses includes the problematic Avian flu strain.
Professor C. William Keevil and Dr. Jonathan Noyce, microbiology researchers at the university, detail the findings in a study being prepared for submission for peer-reviewed publication later this year. "The findings are so pertinent to the current concerns about containing a potential outbreak of the Avian Flu strain that we felt it important to provide some of the preliminary results at this time," Keevil said.
The researchers placed 2 million plaque forming units of Influenza A (H1N1) on coupons of C11000 copper (common, pure copper sheet metal) and on S30400 (common stainless steel) at room temperature and then came back periodically to determine the survival rates of the samples. On the stainless steel, the pathogen declined to 1 million after six hours and to 500,000 after 24 hours. Meanwhile, the copper surface achieved a reduction to 500,000 after only one hour and inactivated all but 500 — a 99.99% reduction — after just six hours.
Keevil notes that the H1N1 strain tested is nearly identical to the H5N1 (Avian) strain and that the effectiveness of copper's antimicrobial properties should be nearly identical as well. He explains that, while vaccines stimulate host antibodies to target specific exposed cell surface structures (epitopes), copper's antimicrobial action probably attacks the overall structure of the virus and, hence, has a broad-spectrum effect. Indeed, other work has shown viricidal activity of copper to the unrelated Adenovirus type 40.
Keevil says these results are "consistent with the demonstrated antimicrobial effects of copper cited in published studies on E. coli O157:H7, Methicillin-Resistant Staphylococcus aureus (the superbug, MRSA) and Listeria." He adds that similar antimicrobial efficacy may be achieved by the infusion of copper ions into fabrics, filters or other materials. However, such applications may have diminished effectiveness over time, because the amount of copper in such materials is much less than in solid copper alloys.
Keevil suggests it would be worthwhile to consider using uncoated copper or high-copper alloys, such as many brasses and bronzes, for common touch surfaces to help minimize cross-contamination. "Door knobs and handles, push plates, countertops, sinks and other frequently touched hardware in healthcare and other public facilities are prime candidates for use of copper alloys to help control the spread of infection."
The studies were sponsored by the Copper Development Association in the USA and the International Copper Association. Dr. Harold Michels of the CDA says he plans to pursue additional studies specifically related to the H5N1 virus. He notes that the association is presently conducting independent laboratory testing of five copper alloys on five different pathogens. These laboratory results will be presented to the U.S. Environmental Protection Agency as part of the process to obtain registration for public health claims under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). Results are expected in the latter part of 2006.
Further information on copper's antimicrobial properties may be found in the Copper and Human Health section on the CDA website, www.copper.org.
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