It is not washing your hands, although you should. This simple act, that we do unconsciously can actually cause you to get the flu according to Digtriad.com.
We do it without even know it, touch our face!
The reasoning is, we touch our face three times and hour. We aren’t washing our hands three times an hour so we are spreading those germs. Since we do it without us knowing we need do it, it is best to carry anti-bacterial or monitor yourself touching your own face and mouth.