American to Europe: Here, Have Some Syphilis

Although the Europeans got silver, gold, converts and tobacco out of their conquest of the New World in the 1500s, the Native Americans got nothing but genocide, as what UCLA biologist Jared Diamond called “guns, germs and steel” killed an estimated 90 to 95 percent of the Native Americans—a horrifying 20 million souls. Nothing was more one-sided than the direction that germs traveled. European conquistadors thoughtfully introduced smallpox, influenza and measles, against which the populations of the Americas had no immunity. Result: disease killed more of them than guns or steel.

Only one disease, scholars have long suspected, might have made the trip east to Europe: syphilis. Circumstantial evidence supported an America-to-Europe trajectory: the first recorded epidemic of syphilis occurred in Europe in 1495, upon Columbus’s return. Although some medical historians have argued that

To trace the origins of syphilis, scientists have mostly studied old bones, which preserve evidence of late-stage syphilis. But because it is tough to pinpoint the exact age of the bones, these studies have been inconclusive. Kristin Harper of Emory University and colleagues therefore studied 21 genetic regions in the genomes of 26 geographically disparate strains of treponemes. Based on how much the different strains had diverged from the basic genetic blueprint, the scientists were able to create a family tree for treponemes. It showed that the strains that cause venereal syphilis originated most recently. Their closest relatives were strains collected in South America that cause the disease yaws. Together, they say, the analyses supports the idea that syphilis originated in the Americas.

But wait. The syphilis that was present in the Americas when Columbus landed (there was a treponemal infection in the Dominican Republic when he arrived) might not have been venereal—that is, spread sexually. “Therefore, it is not clear whether venereal syphilis existed in the New World prior to Columbus’s arrival,” write the scientists. “While it is possible that Columbus and his crew imported venereal syphilis from the New World to Europe, it is also possible that the explorers imported a non-venereal progenitor that rapidly evolved into the pathogen we know today only after it was introduced into the Old World.” If so, then the Americas provided the ancestral germ, but that germ assumed its deadly venereal form only after it became ensconced in Europe.

Critics of the new study say the analysis compared too few DNA sites to reach the conclusions it did, arguing that “no evolutionary order” for the syphilis family of bacteria can be inferred, and urging “caution” in accepting Harper’s claim. Still, this study, combined with earlier work, presents the strongest evidence that the Native Americans got at least a modicum of revenge on their killers.

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