When the Europeans came to the Americas they brought disease that wiped out the native people. Were there diseases local to America that the settlers had to fight against?

by TheAFCfinalist

I've always heard about how the Europeans brought disease that wiped out large portions of the Native American population. Was there any points where the settlers faced a local epidemic in similar ways?

If not, why wouldn't there be foreign germs and bacteria that would affect someone no resistantant to the local stains?

If/when they brought natives back across the ocean did they bring foreign disease that spread once they arrived in Europe?

pgm123

Check out this previous answer by /u/anthropology_nerd: https://www.reddit.com/r/AskHistorians/comments/3jll9c/one_of_the_main_reasons_europeans_were_so_utterly/cuqeccs/

The post is three years old and is certainly not the final answer. Here is an excerpt:

To sum up, the popular assumption that Europeans did not encounter any new pathogens in the New World looks to be wrong. As we dive into the primary sources we find abundant evidence of infections, but it will always be a little difficult to determine, with 100% certainty, that those illnesses were from New World pathogens alone.

/u/400-Rabbits has another useful answer for the British colonies to shed some light on how immunity actually works:

For the Americas, I'm actually going to jump forward in time to Ye Olde Colonial Britain, aka, the American Colonies. Colonists born and bred in the Americas did not have the exposure, and therefore the immunity, to diseases like smallpox. Thus, the Colonies experienced devastating outbreaks whenever the pathogen was re-introduced. (This similarly occurred in South Africa, but I would defer to /u/khosikulu with regards to that region.)