He said the word dormant or is that what you inferred from what he said.
Yes, Dr. Handsfield used the word dormant: "Yes, trichomoniasis often is 'dormant,' that is causes no symptoms with standard tests negative." He didn't say wether it can be transmitted while in the "dormant" state, and how many years it can remain dormant.
perhaps some back ground on why you are asking this will help us help you better :)
could trich go undetected for 12 years? it could but it's not likely.
grace