5,500-Year-Old Fossil Rewrites Syphilis Origin Story

Researchers find ancient Treponema pallidum genome, suggesting the disease is much older than previously thought.

Jan. 28, 2026 at 9:23am

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A 5,500-year-old fossil from Colombia has revealed that the bacteria causing syphilis and other treponemal diseases are several millennia older than previously believed. The discovery challenges the long-held belief that syphilis was first introduced to Europe during the French occupation of Naples in 1495, and suggests researchers have been thinking about the origins of the disease in the wrong way.

Why it matters

This finding significantly alters the understanding of the evolutionary history and origins of syphilis, a disease that has had a major impact on human populations for centuries. It also raises questions about how the disease spread and evolved over time, and what other ancient diseases may still be uncovered.

The details

Researchers led by anthropologist Elizabeth Nelson of Southern Methodist University found a 5,500-year-old Treponema pallidum genome in an individual excavated from a rock shelter in Colombia. This discovery shows that pathogens causing treponemal diseases like syphilis, bejel, or yaws are much older than previously thought, predating the 1495 French occupation of Naples that was long considered the first major syphilis outbreak in Europe.

  • The French occupation of Naples occurred in 1495.
  • The 5,500-year-old fossil was discovered in a rock shelter in Colombia.

The players

Elizabeth Nelson

An anthropologist at Southern Methodist University who led the research team that discovered the ancient Treponema pallidum genome.

King Charles VIII of France

The French king whose army of mercenaries was blamed for the 'Great Pox' syphilis pandemic that swept through Europe in the late 15th century.

Johannes Burckard

A chronicler who noted King Charles VIII's 'fondness of copulation' and reported on his promiscuous behavior that was mirrored by his soldiers.

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What they’re saying

“But the evolutionary history of Treponema pallidum, the lineage of bacteria including the one that causes syphilis, goes way deeper in time.”

— Elizabeth Nelson, Anthropologist, Southern Methodist University

What’s next

Researchers plan to continue studying the ancient Treponema pallidum genome to learn more about the origins and evolution of syphilis and other treponemal diseases.

The takeaway

This discovery fundamentally changes our understanding of the origins of syphilis, suggesting the disease is much older than the 15th century outbreak blamed on the French invasion of Naples. It highlights how ancient pathogens can provide new insights into the long history of human disease.