Shoes on or off in the house?

Does your family wear shoes in the house and you are alright with that? I have a 2 and half year old and a 9 month old and every since I have had the kids I banned shoes in the house. I am a surgical technician and am highly aware of all the germs,pathogens, and just nasty stuff in general that is brought into your home on everything especially shoes. My husband in the other hand is too lazy to take his shoes off and not only brings in nasty germs and what not on his shoes but also the mud and filth as well. Since I'm a borderline germaphobe since working in the health field and seeing all the infections, I am hardcore against it in case one of the kids is exposed to these germs. However, the husband feels "exposure builds immunity." I get where he is coming from but exposure to E.Coli and MRSA is not going to build anyone's immunity. It is only going to cause a serious problem for the kids. Not to mention that America is one if the fewer countries that still wars shoes inside the homes for the very reasons of cleanliness,health, and respect. So how do you feel? Does your family wear shoes inside or no?