Same with the viking coprolites found in Jorvik/York?
It would seem reasonable to say on a statistical sample of 1 we have no reason to believe this was common or uncommon, or do we say on the basis we found one, the assumption is that it was universal?
We know some things like floor rushes were picked to deter fleas, were there oral or rectal treatments which worked for worms?
Prevalence by existence. A coarse but realistic heuristic for very small sample sizes.