[ELI5] How does bacteria transfer from our skin to other surfaces?


I never understood the mechanism behind transferring bacteria from our hands to another surface. For example, assuming we have a standard day-to-day amount of bacteria on our fingertips, for a sufficient amount to transfer to a surface, is a firm press needed or is a slight millisecond touch enough? Does touching a dry surface with dry skin transfer any significant amount? Does any bacteria fall/shed from our skin when we wave our hands around or hover over a surface?

So basically does bacteria “cling” onto our skin? And how easy is it for the bacteria to transfer to another surface?

In: 2

It’s just touch, the more touching, the more bacteria.

So like a quick tap with just your finger tip will leave behind less than a firm press that you hold for a minute. But they both will leave some behind.

Now waving your hands through the air I do not believe spreads any in any significant amount, unless perhaps your hands are west with water flying off them.