I listened to a Stuff You Should Know podcast about Typhoid Mary a while ago. From what I recollected, Typhoid is highly contagious, although I thought there was coughing involved. Turns out nope, just fun things like fevers and diarrhea. Maybe I was thinking of Tuberculosis. Whatever, its not like my name is Dr. Scientist and I always get my facts right.
Check out the podcast, though - its pretty fun.