One possibility is that treponemal diseases emerged even earlier in Eurasia or Africa, and reached the Americas with the first humans to migrate there at least 15,000 years ago

Another is that the bacteria jumped to humans from an animal host, says Anne Stone, an archaeological geneticist at Arizona State University in Tempe who was not involved in the study. Primates and other animals, including rabbits, can be infected with T. pallidum, she notes. “There may be reservoirs we have to think about.”

https://www.nature.com/articles/d41586-024-00191-9

Really it depends if we were already fucking sheep, cattle and/or rabbits 15,000 years ago.