Oligodynamic Research

Brief history and explanation of antimicrobial alloys and an overview of the environmental effects on the efficacy of such surfaces. Also discussion on how cleaning products and disinfectants can affect oligodynamic metal surfaces.

The authors, Victor M. Villapun, Lynn G. Dover, Andrew Cross and Sergio Gonzalez discuss the three major international antimicrobial assessment standards; the Japanese JIS, the European ISO and the United States EPA. This covers what is required for a material to be classified as antimicrobial for each.

Next the factors for antimicrobial behaviour are covered; adhesion of bacteria to antimicrobial surfaces, effects of humidity on antimicrobial performance, effect of geometry, chemistry and physical properties and oxides.

In hospital settings cleaning of traditional high-touch surfaces was identified as a problem, highlighting a 'visual inspection' was generally used. However, when surfaces were actually tested high amounts (70-90%) of surfaces that seemed clean did not meet the required benchmarks. This finding indicates it would likely be beneficial to replace traditional surfaces with antimicrobial copper alloys.

In conclusion the authors found that the antimicrobial activity and cost-effectiveness of copper is interesting, however, the material properties and possible degradation or corrosion from cleaning chemicals needs to be evaluated.

Antibacterial Metallic Touch Surfaces

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A two-year study completed by M. Schmidt et. al. and published on Applied and Environmental Microbiology, 2019, comparing the bacterial concentrations of standard hospital beds to those customised with copper surfaces.

The results showed that even with daily and patient discharge cleaning, the concentration of bacteria was, on average, 2x-8x higher than the suggested healthcare-associated infections (HAI) risk threshold and 89% of samples exceeded the threshold.

In contrast, only 9% of the samples taken from the customised copper beds were over the HAI risk threshold - with 42% found to be free of detectable bacteria.

Self-Disinfecting Copper Beds Sustain Terminal Cleaning and Disinfection Effects throughout Patient Care

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Research conducted on pathogens in water stored in different types of metal pots at the National College, Kathmandu and published in The Nepal Journal of Science and Technology 2009, vol. 10.

The results showed that copper pots exhibited the most effective reduction rate or those metals tested, eliminating E.coli and salmonella within four hours.

Brass pots managed to reduce the E.coli and salmonella in four and twenty-four hours respectively.

And the silver pot reduced E.coli within twenty four hours and salmonella in eight hours.

Oligodynamic Action of Silver, Copper and Brass on Enteric Bacteria Isolated from Water of Kathmandu Valley

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Research published in the Health Environments Research and Design Journal 2013, vol. 9. shows the effects of kitting out hospital spaces with copper alloy surfaces.

The clinical trial set out to discover the benefits - if any - of introducing copper alloy surfaces and components within hospital patient rooms.

This trial found a reduction in bacteria of 83% and also infection rates being reduced by 58% when compared to rooms with components made of standard materials.

The report also went further and estimated the cost of fitting a room with copper alloy components would be recouped in around 44 days due to the reduced number of patients requiring treatment for those infections.

From Laboratory Research to a Clinical Trial: Copper Alloy Surfaces Kill Bacteria and Reduce Hospital-Acquired Infections

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A Research Article by Warnes SL, Little ZR, Keevil CW, published on mBio, 2015, vol. 6 issue 6. compares the survival time of Human Coronavirus 229E (HuCov-229E) on several common surfaces.

It was found that HuCov-229E could survive for up to three days on silicon rubber, and five days on surfaces including teflon, PVC, ceramic, glass and stainless steel.

The same coronavirus strain was inactivated on copper alloy surfaces of greater than 90% copper within 30 minutes of contact.

Human Coronavirus 229E Remains Infectious on Common Touch Surface Materials

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