What they left out:
Viruses can be picked up from surfaces with high rates of public contact: doorknobs and handles, stair rails, shopping cart handles, public phone receivers and mouthpieces and computer keypads, etc.
The more public it is, the higher the risk is. When being exposed to such contact it is especially important to avoid touching your eyes, nose or mouth (mucosal surfaces are an entry point) and always wash your hands when completing a series of such contact.
(face masks don't merely protect by prevent you spreading your own or inhaling others droplets: they also protect by preventing you touching your nose or mouth)
(the above considerations are part of the reason why very young children are at such high risk of catching infections. Another is that they don't have cross-immunity from prior exposure to similar viruses.)
***If flue is at high levels, avoid taking children with you unnecessarily to public spaces. If their presence is not required, leave them at home. And wash your hands immediately upon returning home.****
Avoid any unnecessary exposure to crowds during epidemics.