Contagiousness of Tritrichomonas Foetus?

Quick question-

I did a quick search in this forum on "chronic diarrhea" and I found a couple mentions of Tritrichomonas Foetus. How contagious is it, or can it be carried without symptoms? My cat with chronic diarrhea shares a litter box with two others who don't have diarrhea. What are the chances of this cat having TF when the other two don't?

Thanks,

MissKalamata

I have no personal experience with TF, but have you checked out this site for info?  http://www.highgait.com/page/page/3485008.htm