OK so i am 40 and never had a boil in my life. I never even knew what it really was. About 2 years ago some relatives from West Africa came over and stayed for about 2 months. The little girl had a boil - i thought nothing of it. After they left about a month late i got a boil under my arm! I'll spare you the details but it's pretty gross. It finally went away in a nasy way, six months later I got another one this time on my back (it left a scar too!). I went to my doctor this time http://www.vitals.com/doctors/Dr_Barry_Levant.html he said it's a virus and probably getting it from the guest room bed where they were sleeping. He gave me antibiotics.
I ripped apart all the sheets, bleached everything and literally soaked my bed with 1 1/2 cans of lysol. Since that day, I haven't had another boil and that was about 2 years ago (knocks on wood) - anyway, that's my boil story lol.