[FierceDraka]

...victimized by germ warfare with the deliberate spreading of polio into native communities...

That myth was debunked. There was no germ theory at the time, so no one would have been aware of the concept of spreading germs as a weapon of war.

[muawiyah]

There was a theory of "disease" and "contageion" but no "germ theory of disease". Still, unless you had a large ballista and a sick cow to toss over the walls into the well, there was really no need to wage germ warfare so no one bothered. After all, just keeping folks isolated behind a stockade, or standing guard lest those folks tried to flee, was sufficient to bring about great sickness.

That's why the rules of war allowed a besieging party to slaughter everybody inside a city under siege after so many days ~ after all, the guys standing guard got sick too.

There was no such thing as a truly static defense. Folks gotta' use the toilet Fur Shur.