Ironically, I'm reading The Great Influenza. It spends the first several chapters documenting how terrible the practice of medicine was for centuries, and how it took the profession - especially in America - decades to accept that the scientific method applies to medicine just like it was proving in other disciplines. One effect of this was that in America, the average doctor didn't accept the germ theory of disease for decades after European doctors did. Several nasty epidemics came and went during this time.
If you creationists (or the wacky left - different side same coin) ever decided to become opposed to the germ theory of disease for some ideological reason, you bet I'd be "religiously tenacious" and "defensive" in my defense of the germ theory of disease.