Some infectious agents, it seems, have been with us since the rise of humanity. Bacteria like E. coli or salmonella don’t appear to have one moment enshrined in history where they first appeared on the scene. They’ve probably long been with us, causing disease sporadically but not spectacularly.
Other agents, however, seem to make their presence known. Syphilis is one of these. The first recorded outbreaks of syphilis (caused by the bacterium Treponema pallidum subspecies pallidum) were documented in Europe in 1495. These weren’t syphilis as we know it today. Currently, syphilis is a sexually-transmitted infection that typically has 3 phases of disease. Primary syphilis is the initial phase, characterized by perhaps a lesion on the genitalia. This typically resolves on its own, and the patient may either get better or progress to secondary syphilis. Secondary syphilis is characterized by a distinctive rash, which is fairly unique in that it is present not only on the usual areas of the body (typically the extremities for this rash), but also presents on the palms of the hands and soles of the feet. This feature could be diagnostic, but it’s not always present. Infection progresses to the secondary phase generally weeks to months after the primary symptoms.
Tertiary syphilis is the final phase of the disease, and the most difficult to diagnose on symptoms alone. There can be neurological involvement, leading to the “madness” of syphilis; or it can attack the cardiovascular system or the digestive system, leading to heart failure or painful bowel problems that can last for years. Tertiary syphilis is not only insidious in its diverse array of symptoms, but also in its lag time from initial infection: as little as one year, or as many as 50. The disease is a complex and often mysterious one.
However, just as mysterious has been the origin of T. pallidum. As I mentioned, the disease we see today bears little resemblance to syphilis when it was first recognized in Europe during the late 15th century. At this point, syphilis wasn’t a hidden venereal disease: it was a highly virulent infection that could run its course in a matter of weeks to months, covering the victim in sores from head to toe until they died an excruciating death. However, this highly pathogenic form was soon replaced with a milder version of the disease, more similar to what we see today.
But a larger question looms: where did syphilis come from? It’s widely agreed upon by scholars that syphilis appears to be a “new” disease to Europeans at this point in history–so had it been hiding in another reservoir prior to this time? Did a new subspecies emerge from older, related infections? Or did the voyages of Columbus bring this microbe back to the Old World from the New? There have been a number of conflicting publications on this over the past several years (and indeed, the debate is as old as Columbus’ voyages themselves), with archaeological evidence and that from microbiology sometimes coming into conflict regarding the origin and evolution of subspecies of Treponema pallidum. A new study swings it back to Columbus, suggesting that Treponema pallidum likely has its origin in the New World. More after the jump…
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