In June 1495, the Italian historian Niccolo Squillaci wrote a letter describing a horrific disease that was sweeping through Europe.
“There are itching sensations, and an unpleasant pain in the joints; there is a rapidly increasing fever,” he wrote. “The skin is inflamed with revolting scabs and is completely covered with swellings and tubercules, which are initially of a livid red color, and then become blacker.” And, tellingly, “It most often begins with the private parts.”
“I exhort you to provide some new remedy to remove this plague from the Italian people,” he concluded. “Nothing could be more serious than this curse, this barbarian poison.”
More than half a millennium later, there are some things we know about that “barbarian poison.” We know that it was syphilis, and that Squillaci’s letter was one of the first documents describing the first recorded epidemic of the disease. We know that it’s caused by a spiral-shaped bacterium called Treponema pallidum, and that it spreads through sexual contact. And we know that a cure wouldn’t be discovered until penicillin was found to be an effective treatment in 1943.
What we still don’t know, though, is where syphilis came from.
There are two main theories about the origins of the 1495 outbreak. The first, known as the Columbian hypothesis, holds that Christopher Columbus and his crew carried the disease from the New World back across the Atlantic. Records from the outbreak indicate that the disease hadn’t been seen before in Europe, Columbian proponents argue, meaning that timing-wise, a cross-continental import was the likeliest explanation.