Are you saying that syphilis was widespread among native Americans? Post aside, that is a fascinating fact.
It is interesting. It was terrible that early explorers carried diseases that killed millions in the regions they went to. Its reassuringly symmetric that diseases went the other way as well. I didn't know that 100k+ still die from it every year.
It's also possible that it coincidentally originated in Europe around the same time and spread to the Americas. By the time people started looking into where it had come from, it was widespread in both places and the exact origins were obscure. Nobody appears to have recorded the prevalence of syphilis in the Americas during the early years of European contact.