The diseases or sicknesses of beer and wine had from time immemorial baffled all attempts at cure.
Pasteur first formulated the idea that bacteria are responsible for the diseases of fermented liquids; the corollary of this was a demand for pure yeast.
Endemic diseases are unknown and epidemics are rare.
The pear is subject to several diseases caused by fungi.
Specifically, a virus or bug passed to a pig is considered a huge threat in the medical community, because pigs can pass their diseases onto humans.