Of course, in the Middle Ages, it was easier to believe that something would stop it because whatever it was, having natural origins would stop on its own.

That's one reason why folk medicine is so hard to eradicate. Not only do they have a few effective things -- willow-bark tea -- and the placebo effect, there is the way most diseases are self-limiting, so you take the cure until you get better.

If it's actually driven by malice, that would be harder. I observe that in witch trials, the witches' purported motive were usually not just malicious but vindictive.

Anything that would stop them would be put to use. Alas, no doubt, that would include counter-goetia.