A microscope hides the ultimate agent of contagion. Be careful!

We can be infected with viruses, bacteria and other biological agents through the air we breathe, the objects we touch, the insects that bite us and in many other ways. Although we can infect others with diseases, we are capable of being contagious in ways that are not biological. We live in society and we constantly express our preferences and opinions. This means that contagion can also be intentional. We are powerful agents and we play a very important role in contagion, whether we are spreading it or stopping it.