10 May 2014, 20:01
You don't have to be sterile, but keeping hands washed after handling mucky or dubious materials will help. Also trying to contain colds or flu viruses by using tissues and suchlike. Just basic cleanliness really. To be honest, if a "bug" is really determined to get you it will, and you can't fight viruses off at all times.
The only thing necessary for the triumph of evil is for good men to do nothing.