Scientists Find an Ancient Syphilis Relative in Brazil

People who lived with painful mouth and skin sores on the south coast of Brazil some 2,000 years ago carried the oldest known evidence of a syphilis relative. Treponema pallidum, the bacterium that causes syphilis, is "one of the least well understood common bacterial infections," one expert tells CNN. Yet a new study offers some interesting clues about how it came to be. Researchers examined evidence of a bacterium eating away at bones in skeletons buried at the Jabuticabeira II site near Brazil's southern city of Laguna. They found treponemal DNA in bones from 37 of 99 individuals sampled. From four samples, dated from 350 BC to AD 573, researchers were able to construct "the oldest-known genome of a syphilis relative yet discovered," per Live Science.

"Unexpectedly, these genomes are remarkably similar to those of the causative agent of modern day bejel," or endemic syphilis, according to the study published Wednesday in Nature. The causative agent of bejel is Treponema pallidum endemicum, which is "virtually indistinguishable" from T. pallidum when viewed under a microscope, according to the National Organization of Rare Disorders. It's usually found in arid regions, so "this is a completely different environment than where you expect to find it," lead study author Verena Schünemann, a paleogeneticist at the University of Basel, tells Business Insider. In the ancient population, "the bacteria likely also caused similar skin lesions [to bejel]," Schünemann adds, per Live Science.

The first genetic evidence of a syphilis relative prior to Christopher Columbus' arrival in the Americas pushes back the origin of T. pallidum by millennia. The analysis also suggests T. pallidum and T. pallidum endemicum diverged from a common ancestor about 14,000 years ago, per Business Insider. This doesn't disprove the long-held theory that syphilis was carried from the Americas to Europe by Columbus and his Spanish conquistadors. But it "means these bacteria could easily have traveled around the world several times with the different human migrations, much earlier than Columbus' expeditions," per Insider. Live Science highlights a 2015 study that found evidence of congenital syphilis in a juvenile who lived in what is now Austria prior to 1492. (More discoveries stories.)