for National Geographic News
Famed explorer Christopher Columbus and his crew unleashed the scourge of syphilis on Europe, a new genetic study suggests, though some experts say the data is not conclusive.
The research adds more fuel to a controversial debate on the origins of the devastating sexually transmitted disease that can cause blindness, mental illness, and death.
Europe's first-known venereal syphilis epidemic occurred during the years immediately following Columbus's return, fueling a long-held theory that the explorer carried the disease to the continent.
Study lead author Kristin Harper and colleagues compared genetic data from 26 strains of the treponema bacteria family—those responsible for venereal syphilis as well as nonvenereal forms of the disease—and closely related ailments such as yaws, a tropical bacterial infection.
The results showed that modern-day syphilis strains resembled those found in South America.
This New World origin for syphilis strongly supports the Columbus theory, said Harper, an evolutionary biologist at Atlanta's Emory University.
"We hope to find genetic differences we can use to build a family tree of these bacteria," she added. "In doing that we hope to get an idea of where and when syphilis evolved."
Bones on each side of the Atlantic have yielded some tantalizing but inconclusive clues suggesting where and when the disease existed before Columbus's voyages.
Numerous pre-Columbian Old World remains appear to show signs of syphilis, including pitted skulls and unnaturally large lower leg bones, some researchers say.
But few examples survive, and those that appear to show syphilis may in fact be evidence of other related bacteria.
"Diagnosis of specific [syphilis-causing] diseases can be problematic in skeletal remains from archaeological sites, because they are often fragmentary and poorly preserved," said Charlotte Roberts, a bioarchaeologist at Durham University in the United Kingdom.
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