“due primarily to the ongoing depopulation caused mainly, though not exclusively, by Eurasian diseases.”
I read fairly recently that the worst plague was not brought by the Spaniards at all, but was endemic to the area.
Wish I could find that again.
See post 29. Like most attempts to reconstruct epidemic effects from centuries ago, these claims are speculation.
However, while the disease organism itself may have been endemic, it does not appear to have ever struck before (or since for that matter), which indicates something about the Spanish invasion may have contributed to it breaking out.
The most common opinion is that it was hantavirus, which is found all over the world but seldom affects humans, certainly not in epidemic form.
But when hanta does hit, it is remarkably deadly. Killed my sister’s best friend in CO. Dead less than 36 hours after symptoms started, and probably less than four days after exposure. Symptoms somewhat similar to Ebola. Very nasty.