Could someone identify this book?

I didn’t want to hijack the movie thread (but thanks for the idea) so:

I once read a book (fiction) about a doctor in Florida who treats some patients. They seem to have the plague. Eventually, everyone has this disease (which they blame on water pollution) except the doctor and his kid(s?) They flee to New York. Eventually, they realize the doctor hasn’t gotten sick because he spends so much time around X-rays and his kids hasn’t gotten sick because of way too much TV. I remember someone, I think the doctor, climbing down an elevator shaft with a kids on his back because he’s trying to escape from the sick people in the building.
I can’t remember the name of the book or the author. I don’t remember when it was written but I’d have to say it was at least 10 years ago because I was still in middle school.

Help!

I have no clue, congodwarf, but since no-one answered yet: Could it be written by Robin Cook? He seems to write a lot of doctor/thriller stories. Hope that helps.