Table 2.
Studies about the copper effect on respiratory viruses.
| N | Author | Year | Virus | Substrate | Media | Results |
|---|---|---|---|---|---|---|
| 1 | Miyamoto | 1998 | Influenza (H1N1, H2N2, H3N2) | Copper chelates | Madin–Darby canine kidney (MDCK) | 5 μM copper inhibits apoptosis of the 98% to 100% influenza virus, independent of the influenza type. Inhibited viruses release during apoptosis |
| 2 | Han | 2005 | SARS-Cov, Escherichia coli | Cu/AI203 | Metal catalyst surface | After 5 min of exposure, the infectivity dropped down to undetectable levels. |
| 3 | Noyce | 2007 | Influenza (H1N1) | Stainless steel and copper | Metal surface | 500,000 virus particles remain infectious after 24 h of incubation on stainless steel; 500 particles were active after 6 h on copper incubation. |
| 4 | Horie | 2008 | Influenza (H9N2) | Cu2+ at 2.5- to 250-μM concentrations | MDCK | Titer reduction of 3 and 4 log within 3 and 6 h of exposure |
| 5 | Borkow | 2010 | Influenza (H1N1, H9N2) | Copper oxide | Impregnated cotton textile | After 30 min of simulated breathing, 5.03±0.54 log10TCID50 virus titers were recovered from control masks. No influenza titers were found on copper oxide–containing masks (≤0.88 log10TCID50). |
| 6 | Imai | 2012 | Influenza (H5N1, H5N3) | Cu2+ (0.1 mL) | Impregnated cotton textile | Titers of H5N1 decreased by >5.0 log10 and 5.0 log10, respectively, after 30-s incubation on the textile. H5N3 decreased at similar rates. |
| 7 | Fujimori | 2012 | Influenza (H1N1) | Nanosized copper iodide (CuI) | Aqueous solution concentration dose. 17 μ/mL | One-hour exposure resulted on the 50% effective concentration dose |
| 8 | Warnes | 2015 | SARS-Cov (HuCoV-229E) | Copper alloy surfaces | Different dry surface | Complete and irreversible destruction of the coronavirus. Rapid damage to the surface proteins and membrane, braking the envelop. Coronavirus genomic RNA revealed nonspecific fragmentation |
| 9 | Minoshima | 2016 | Influenza (H1N1) and bacteriophage Qβ. | Ionic copper and silver cuprous oxide (Cu2O) | Solid-state and soluble compounds | Solid state of cuprous oxide (Cu2O) inactivates influenza A virus and bacteriophage Qβ; however, solid-state cupric oxide (CuO) and silver sulfide had little antiviral effect. |
| 10 | Ito | 2016 | Influenza (H1N1) and HIV (type 1) | Sodium copper chlorophyllin | MDCK | Sodium copper chlorophyllin inhibited HIV adsorption at 2.5 mM (P < 0.05) and inhibited the influenza virus adsorption at 200 μM (P < 0.05). |
| 11 | Zerbib | 2020 | Hand-transmitted healthcare-associated infection | Copper alloy surfaces | Different dry surface | The relative risk of hand-transmitted healthcare-associated infection was significantly lower in the copper-equipped surface (RR 0.3, 95% CI 0.1–0.5). |