[jandrewrogers]

It is interesting precisely because we know it wasn’t smallpox and we know it killed a large portion of the native population in places like Mexico. 1545 was just the first year the disease was documented by Europeans. There have been a dozen epidemics of this into the 19th century and then it just disappeared, long before smallpox was eradicated. It also didn’t spread indiscriminately across North America, it was correlated with specific types of environments.

The particular epidemics in question killed both natives and Europeans. Furthermore, the manifestation of the disease was unfamiliar to the Europeans.

You are assuming facts not in evidence. This is actually pretty interesting because it suggests there is a latent pathogen with a very high fatality rate in the Americas. It wouldn’t be the first.

We saw this with the hantavirus. The Old World hantavirus species were never dangerous enough to even deserve a footnote, but the New World hantavirus species are essentially like Ebola. But outbreaks are very rare and hantavirus doesn’t seem to be communicable between humans, so the damage is localized. The hemorrhagic fever that killed millions of people in the desert-y parts of the Americas a few centuries ago was something else.