One of the most common phobias I encounter these day is mysophobia, 
the fear of germs. While it's wise to avoid needless exposure to viruses, bacteria, and microbes that can tax our immune systems, much of
the worry is misplaced. This has resulted in the misuse of antibiotics and an increasing number of hand sanitizing stations in public places.
The fact is that germs constantly surround us. The breath you just took contained all manner of microscopic organisms, yet it is unlikely that any of them will manifest in a disease. That's because the circumstances have to be just right for them to take hold and threaten our well being.
Thank your immune system for that! Every moment, without a conscious thought from you, your immune system (controlled and coordinated by your nervous system) is flawlessly eliminating these threats--until it can't. Then we get sick.
Don't blame the germs! Instead, find out why your immune system was compromised and couldn't do its job. Germs don't automatically cause disease any more than baseball bats cause home runs.