Antimicrobials: Healthcare's Silver Bullet Against HAIs?

“Silver has been known for its antimicrobial properties for a very long time,” says Mark Rupp, MD, professor in the Department of Internal Medicine, Section of Infectious Diseases at the University of Nebraska Medical Center. “Silver has broad-spectrum activity and I think it is a very good antiseptic. However, there are a few drawbacks; there are mechanisms of resistance that have been described specifically for silver, and there have been outbreaks involving silver-resistant organisms particularly in burn units, where there is widespread use of silver as a topical antiseptic agent. The watchword is judicious use of these antimicrobials. Application of silver to medical devices is an appropriate use in some clinical settings.”

>>Copper

While silver ion technology is most prevalent, other metals are beginning to be respected for their potential to help kill microorganisms. Last year the Environmental Protection Agency (EPA) approved the registration of antimicrobial copper alloys with public health claims that copper, brass and bronze are capable of killing harmful bacteria. Copper is the first solid surface material to receive this type of EPA registration, which is supported by extensive antimicrobial efficacy testing. The EPA registration is based on independent laboratory testing using EPA-prescribed protocols that demonstrate the metals’ ability to kill specific disease-causing bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Noyce et al. (2004) showed that on copper alloy surfaces, greater than 99.9 percent of MRSA are killed within two hours at room temperature. According to the Copper Development Association (CDA), copper alloys can be used for frequently touched surfaces, including door and furniture hardware, bed rails, intravenous (IV) stands, dispensers, faucets, sinks and workstations. The CDA reports that 275 copper alloys, including brass and bronze, have been registered with the EPA as antimicrobial materials that kill bacteria such as Staphylococcus aureus, Enterobacter aerogenes, Escherichia coli O157:H7, and Pseudomonas aeruginosa.