And unless you have open wounds, as long as you wash your hands, you won't get sick. But the key is to wash your hands the right way.
According to health experts, that means wetting your hands with water, washing all surfaces of the hands – including between the fingers and underneath the nails – rinsing and then repeating the cycle all over again.
If you use a public bathroom to wash your hands, Tierno recommends you avoid touching faucets or door handles.
"Use paper towels to open or close faucets and doors, then use the towel to open the door, and then throw the towel in the trash outside the bathroom," he said.
Gerba agrees that faucets are probably the dirtiest part of public bathrooms, but says door knobs aren't as dirty because people tend to wash their hands and then open the door.
In the event you can't get to a sink, you should use gel hand sanitizer that's at least 62 percent alcohol. Rub it all over your hands for about 15 to 20 seconds and then let it dry.
As long as you use common sense and are aware of all the bacteria that could be around you, can easily avoid getting sick.
"You don't have to live in a bubble. These are just easy ways to prevent unnecessary illnesses," said Tierno.