This feels... outdated? It wasn't rats, it was fleas, we even know the mechanisms through which it spread.

- Fleas bite diseased humans. The bacteria reproduce in their salivary glands to the point at which it clogs their proboscis. When they bite another human, they "sneeze" and release all of that bacteria into the blood.

- Fleas are temperature sensitive. When a person died and went cold, they moved to a new host. When the host's temperature became too high, they likewise migrated to new hosts.

I'm pulling this from an undergraduate degree a decade ago, which wasn't exactly teaching us cutting edge discoveries when it came to this. This feels like saying that some are beginning to believe fat isn't that bad for you in your diet. It's already established science, pop culture hasn't caught up.