I had fears this bad during the winter when everyone around me was getting the SV*. What helped me was to understand the facts of how and why people V*. Then your rational mind will KNOW that going to bed early, or breathing next to a moving bus will NOT make you sick. You can avoid touching your hands to your face, and always wash your hands very well before eating anything and then remind yourself that you do this consistently and you are VERY unlikely to get a SV* because you're so careful. Knowing that your food is fresh, washed, or fully cooked helps too. Focusing on things like this in your rational mind will make you feel so much better.

I also like to consider the reason someone is V*ing. If it's because they've overeaten, it disturbs me, but I find comfort in the fact that I can't catch it.