Very rarely. Like maybe once every 3 years I will get a cold, The last time I was sick enough to go to the Dr. was when I was 14 and had an ear infection. I try and avoid using hand sanitizers and cleaning with anti-bacterial products (Although with my new job I have to sterilize everything, I'll be interested to see if I get sick more often). I think that germs help you build up your immunity, so that you can better fight off the bad ones.
Since I am so rarely actually sick. I do tend to take sick days for mental health reasons if I am having a lot of panic episodes (I usually do this about 2 or 3 days a year). I think that taking care of myself in that way also helps that from progressing into a physical disease.
Somehow I have avoided a lot of the physical problems, but I think I have more than enough mental health issues to make up for it