What do you say to someone who tries to touch your baby?

I want to be polite to people and still make the message clear that just because I show them my baby, that I DO NOT want them to touch her. She's only 2 months old.

Sometimes I just don't even go anywhere because I'm afraid someone will try to touch her and I'll have to slap their hand (lol.) But seriously!! Why can't people just have respect and know not to touch?? I didn't carry a baby in my womb for 9 months, squeeze and push her through my small vagina hole, for the whole world to touch her!!! She's MY baby and I don't want your germs on her! People are so rude.