[Buttons12]

First you’d have to explain that disease comes from tiny invisible creatures and not as a punishment from a deity.

"...there are bred certain minute creatures which cannot be seen by the eyes, but which float in the air and enter the body through the mouth and nose and cause serious diseases."

Marcus Terentius Varro, died 27 B.C.

[DBrow]

But that did not become common, regular practice for a long time. Imagine Varro as a time traveler from the late 19th century trying to explain this. It cropped up in the 1500’s and again in the 1600s but was not really acted upon until the late 1800s.

If Varro had been accepted, the Black Plague might have been mitigated.