Researchers using artificial skin have found that touching surfaces contaminated with SARS-CoV-2 can lead to the transfer of the virus to the skin. The study results have been published on a pre-print server. There is evidence that the virus can also spread when people come in contact with fomites. The researchers used an artificial skin called Vitro-skin because it is very similar in properties to natural human skin.
The team made an artificial plastic finger and attached the artificial skin to it. They placed a droplet of a SARS-CoV-2 suspension on each solid surface they tested. They contacted the artificial skin for 10 s or 30 minutes with this contaminated solid, then removed the skin and placed it in a solution to remove the virus from it. The solution with the virus was tested to check its infectivity of Vero E6 cells. They found that when a wet droplet with the virus is present on a surface, even a brief, light touch can transfer the virus to the finger. For glass, stainless steel, and Teflon surfaces, the transfer ratio was about 13-16%. Touching the surface after the droplet had dried transferred a lesser amount of virus, about 3-9%. Infected people can shed a large number of viruses, so the amount transferred can be quite significant.
They did find that the porosity of the solid plays a role in virus transfer. There was less transfer of the virus when the droplet was placed on wettable materials such as tissue, wood, and porous glass, and the droplet could penetrate them. The droplet and the virus become trapped in the pores, and thus less is present on the surface for transfer. They also found that the virus trapped in the paper once the droplet had dried can be reactivated and resuspended. This was not true for the other porous materials they tested.
Ref link: https://www.medrxiv.org/content/10.1101/2021.04.24.21256044v1