To breeze through
the basics, the debate on the origins of syphilis remains inconclusive. Its ancestral form - also the progenitor of friendly spirochete bacteria like
yaws, pinta, and
bejel ("endemic" or "non-venereal" syphilis) - had an ancient Old World origin. Syphilis' first indisputable appearance was at Naples in 1495; how it
got there is unclear, but that it erupted across Europe as infected soldiers sloughed off the retreating French army is certain. The intervening period, between prehistory and 1495, is less clear.
The disease could have [1] remained in the Old World until the Age of Exploration, have [2] originated in the New World and eventually been picked up by Columbus' men, [3]
speciated from a less awful disease
on contact with Columbus' men, or [4] been present on both sides of the Atlantic - only coming to European attention when a particularly virulent form struck an army in a manner visible to historians.
The available evidence leans toward more toward the 2nd and 3rd possibilities than toward the 1st and 4th. That said, here's the breakdown:
Scenario 1-
Syphilis was present only in Europe for centuries prior to the Columbian Exchange (so the argument goes), but weaknesses in diagnosis saw it mistaken for leprosy. Supporting this thought is a matter of timing - in 1490, the pope ordered "leprosaria" abolished across Europe, theoretically setting huge numbers of lepers out on Europe's roads (from Mann's
1491). Syphilitic symptoms may have been described as early as by Hippocrates in classical Greece; skeletons in pre-contact Italy have been reported to have signs similar to the disease visible on their bones (the same applies to skeletons in Britain, according to
1491, and in Austria).
The leprosy idea isn't a hopeless argument, but the evidence is fairly weak. The disease has been known as "the great imitator" for the overlap of its symptoms with other contagions, suggesting that millennia-old descriptions are less than definitive. And the skeletal evidence is as yet non-peer-reviewed. But the scenario also falls down in denying an American presence of the disease.
Scenarios 2 and 3-
Evidence of an American origin seems strong. The appearance in Europe was remarkably sudden, virulent, and deadly - if the disease had been hiding under the cover of leprosy for centuries, it had clearly mutated to a new and more dangerous form at an awfully coincidental moment. That might instead suggest a foreign disease entering a virgin field.
Speaking from historical evidence, Ruy Díaz de Isla - a prominent Spanish doctor - claimed to have observed and attempted treatment on the crew of Columbus' first voyage. One of his patients, the captain of the
Pinta, supposedly died of it within months of returning from the voyage. Contemporary Europeans (as opposed to the man-on-the-street accusations [It's the Neapolitan Sickness! The French Pox! Spanish Sickness! Canton Rash!]) were comfortable accepting its origin being West Indian. For some reason, this eye-witness perspective doesn't come up much in these debates, but that's a tangent.
And back to skeletons. Skeletons showing pathology similar to spirochete diseases such as yaws and syphilis were found across much of North and South America according to
this study. Interestingly, southern populations (New Mexico, Hispaniola, Florida, and Ecuador) appeared to have syphilis, while northern ones (Ohio, Illinois, and Virginia) showed signs more reminiscent of yaws.
In terms of
in vivo biology, there's still more evidence. Genetic studies suggest that
yaws is the ancestral strain of the
Trepanema family, and it is generally assumed to have originated in Africa, possibly spreading with the first human migrations from the continent. Endemic syphilis or
bejel may have diverged from yaws early in human history, and currently hangs out in West Africa and the Eastern Med.
This study tells a much more detailed story of the related diseases - suggesting an intermediate ancestral form of the disease separates the two confirmed Old World varieties from the two-or-three New World varieties. Those putative New World types? Syphilis, a variety of yaws found in Guyana (possibly representing a more baseline evolutionary branch for the Americas) and
maybe? other parts of northern South America, and pinta.
Pinta itself is suggestive just by its existence. A close, but almost entirely harmless, relative of syphilis
entirely localized to the New World. Pinta was historically present in tropical parts of Mexico, Central America, and Colombia.... yet
nowhere in the Old World.
The more....
wet....approach to biology thus demonstrates two syphilis relatives (pinta and the Guyanese yaws) currently limited to the tropical Americas, with the latter more closely related to syphilis than to confirmed Old World Trepanema spirochete critters. In parallel, dry biology suggests something like Treponema reached the Americas early, something like syphilis inhabited Meso-America, northern South America, the Caribbean, and adjacent areas from their early history, while something like yaws was present in North America as early as 500 years before contact.
Scenario 4-
It's also possible that related versions of the disease were on both sides of the Atlantic to begin with, but happened to really take off in 1495 Italy, for unknowable reasons. If that is the case, though.... It's still possible that a more virulent New World variety took center stage, catching attention the long-conflated-with-leprosy form had never earned. That would remove all questions raised about questionable skeletal remains, but how to square that with the genetic evidence? I don't know. It might not be possible.
This is, so far as I can tell, the possibility space we have to work with.
Which is to say we probably ought to consider writing these diseases into all of our New World timelines going forward.
(Thanks to
@Jared , by the way, for pointing me in this direction.)
I'll return to this in another post with my speculation on what this could mean in our terms - for timeline writing.