As a syphilis epidemic raged in Europe beginning in the late 1400s, Science notes that some researchers suspect that Christopher Columbus or his crew may have brought the bacterium that causes it back from the Americas. Other Treponema pallidum subspecies, it notes, cause yaws and bejel, diseases that are known to have been circulating in the Americas prior to Columbus' arrival.
But by sequencing four ancient T. pallidum genomes, a University of Zurich-led team has shed doubt on that theory. As they report in Current Biology, the researchers collected samples from nine individuals who lived in Finland, Estonia, and the Netherlands, four of whom had a Treponema infection. Using a molecular clock approach combined with radiocarbon dating, they estimated that these bacteria dated back to between the early 15th and 18th century — suggesting that syphilis may have been present in Europe before Columbus' voyage.
Mississippi State University's Molly Zuckerman tells Science, though, that the findings don't fully rule out the Columbus theory as the date ranges are wide.
"It's not yet the final nail in the coffin," co-author Johannes Krause from the University of Tübingen adds at Science, noting that more European samples are needed.