The main way that illnesses like colds and flu are spread is from person to person in respiratory droplets of coughs and sneezes. This is called "droplet spread."

This occurs when droplets from a cough or sneeze of an infected person move through the air and are deposited on the mouth or nose of people nearby. Sometimes germs also can be spread when a person touches respiratory droplets from another person on a surface like a desk and then touches his or her own eyes, mouth or nose before washing their hands. We know that some viruses and bacteria can live 2 hours or longer on surfaces like cafeteria tables, doorknobs, and desks.

The following are just a few of the simple ways you can avoid getting and spreading germs: 

• Cover your mouth and nose when coughing or sneezing
• Cough or sneeze into a tissue and then throw it away. Cover your cough or sneeze if you do not have a tissue, then, clean your hands and do so every time you cough or sneeze. 
• Wash your hands properly

That's about the same time it takes, for example, to sing the "Happy Birthday" song twice. Be sure to wash all surfaces of your hands, including your wrists.