DNA Study Tracks Europe’s Medieval Syphilis Epidemic

ZÜRICH, SWITZERLAND—Science Magazine reports that a new study of DNA samples extracted from the remains of people buried in Finland, Estonia, and the Netherlands suggests that several diverse strains of syphilis were circulating in Europe in the late fifteenth century. It had been previously thought that Treponema pallidum, the bacterium that causes the disease, was introduced to Europe by Christopher Columbus and his crew upon their return from the New World in 1493. Verena Schuenemann of the University of Zürich and her colleagues looked for bacterial DNA in the remains of nine Europeans whose skeletons bore bone lesions associated with syphilis. They were able to recover bacterial DNA from four of them. The researchers then compared the DNA with modern syphilis to track the changes in the genome and estimate the ages of the strains, calibrated with carbon dates of the skeletons and their wooden coffins. They found evidence of a previously unidentified strain of syphilis, and dated two other strains to the early to mid-fifteenth century. They also detected evidence of yaws, another disease caused by the bacterium which is found today only in the tropics. “Either Columbus brought a whole bouquet of strains, or this diversity was present there before,” said archaeogeneticist Johannes Krause of the Max Planck Institute for the Science of Human History. He acknowledges that additional samples and more precise dates are necessary to confirm the presence of syphilis in the Old World prior to Columbus’s travels. For more, go to “World Roundup: Austria.”