In the spring of 1495, the French army, under the reign of Charles VIII, faced an unexpected enemy. Soldiers weren’t battling an advancing foe but rather a mysterious and grotesque disease. What began as lesions on the skin quickly erupted into a full-scale epidemic. Within months, the illness spread across Europe, leaving survivors with disfigurements that haunted their bodies and minds. Historians now agree: this was syphilis’s first recorded rampage.

Its origins, however, remain a point of contention. Did it hitch a ride back to Europe with Columbus’s crew after their voyage to the Americas? Or had it lurked in Europe long before the New World was even a concept?

A new study out this week may finally resolve this centuries-old mystery.

The American Connection

Led by researchers from the Max Planck Institute for Evolutionary Anthropology, the study focused on five ancient skeletons unearthed in South America. The bones bore the telltale signs of treponemal diseases — a family that includes syphilis, yaws, and bejel. Using cutting-edge genetic analysis, the team uncovered bacterial genomes from these ancient remains, some dating back 8,000 years.

“Four of the five skeletons are dated before 1492, meaning that this pathogen diversity was already present in the Americas at the time of [Christopher] Columbian contact,” explained Kirsten Bos, a molecular paleopathologist at the institute. The study’s findings strongly suggest that the Americas acted as a reservoir for the bacteria that would eventually evolve into modern syphilis.

By comparing ancient treponemal DNA to contemporary strains, the researchers reconstructed the evolutionary timeline of Treponema pallidum, the bacterium behind syphilis. Their results indicate that the sexually transmitted strain likely emerged around 500 to 600 years ago. This coincided with Columbus’s arrival in the New World. “The data clearly support a root in the Americas for syphilis and its known relatives,” Bos concluded.

From Local Scourge to Global Epidemic

The implications of this research are manifold. The study paints a grim picture of colonialism’s unintended consequences. While European explorers brought smallpox, measles, and other deadly diseases to the Americas, syphilis may have been the New World’s equally devastating gift in return.

“Indigenous American groups harbored early forms of these diseases, but Europeans were crucial in spreading them worldwide,” noted Bos. As European powers expanded their reach into Africa, Asia, and beyond, the disease found fertile ground to flourish, aided by human trafficking networks and global trade routes.

But questions remain. Evidence of syphilis-like bone lesions predating 1492 has been found in Europe, leading some experts to speculate that treponemal diseases might have existed there independently. “The search will continue to define these earlier forms, and ancient DNA will surely be a valuable resource,” said Johannes Krause, co-leader of the study.

A Persistent Threat

Despite the advent of antibiotics like penicillin, syphilis has not been eradicated. Each year, over 8 million new infections occur, and congenital syphilis — when the disease is passed from mother to child — leads to approximately 200,000 stillbirths globally. Alarming trends show a rise in cases among young adults, likely driven by declining condom use and antibiotic-resistant strains.

“Syphilis has the capability of adapting to any environment. It raises the question whether new, more aggressive diseases could emerge in the future,” warned Kerttu Majander, an archeogeneticist from the University of Basel, in an interview for Deutsche Welle.

The latest findings also underscore the need for vigilance. By unraveling the deep history of this ancient pathogen, scientists hope to anticipate and combat its modern resurgence. “The history of syphilis isn’t just about the past,” said Bos. “It’s about understanding the ways pathogens evolve and preparing for what may come next.”

As researchers continue to excavate the genomic clues buried in ancient bones, the full story of syphilis is slowly coming into focus.

The findings appeared in the journal Nature.