Well regardless, we know North American natives had extensive sanitation practices and epidemics were quite rare. Syphilis, tuberculosis, intestinal parasites, and Chagas disease were all present but rarely turned into mass outbreaks.

Mass graves are almost completely absent and life tables show steady and predictable mortality curves over centuries

https://www.pnas.org/doi/10.1073/pnas.2024802118

https://pmc.ncbi.nlm.nih.gov/articles/PMC1071659/

https://globalbiodefense.com/2020/06/15/what-the-archaeologi...

I find it hard to believe that Europeans living in close quarters with livestock didn't result in increased rates of epidemics tbh but I'll take your word for it