Dear Patricia,

Yes you are right, years ago when the hypothesis that ulcers were caused
by bacteria was set forth, it caused many a great laugh. Not anymore.
Transmission is tought to be "hand mouth" but nobody really knows.
Probably not as early as you felt (usually the practice of prechewing
occurs between 6 and 18months) because it seems that the antibodies
indicating when humans get in contact with the germ start increasing in
preschoolers if I remember correctly.  By the time people are in young
adult years, most have met the bacteria, but not every one gets sick!

so much for GI trivia!

Maryelle