Actually, in the days of Sir Francis Drake, virtually all pirate ships were democracies.



You have it backwards. Treponema pallidum appears to have originated in the old world. Hippocretes described the disease in ancient Greece, and they've found evidence of the disease in Pompeii, in England, and so forth. There are several forms of syphillis, and one was known as lepra, because it was originally thought to be a form of leprosy.

Infectious diseases are actually populations of a species. They have to have a constant supply of nutrition - new organisms to infect - in order to survive. The spare population of North America amounted to a permanent quarantine of everyone, which makes most diseases die off.

Venereal diseases are, by definition, diseases that are extremely difficult to transmit from one person to another. You can give someone the flu by sneezing on your hand, opening a door, and then someone you never even meet opens the door later. Venereal diseases, on the other hand, require not only intimate contact, but usually the exchange of body fluids. Because diseases "go with the flow", it is far easier for men to infect women than for women to infect men.

In the native american tribes, it was routine for visitors to be offered all the hospitality that the village could offer - including a bed warmer. Most tribes practiced a greater degree of exogamy than required by today's incest laws - not only could a father not be a first cousin or closer relative of the mother, but he needed to come from a different village. Travelers were assumed to be the best and the brightest that their communities had to offer, and it was considered good manners for them to repay the host by making a donation to the village's gene pool.

If these traditions had spread a disease which causes infertility (not to mention insanity), the only surviving native americans would have been those who were genetically immune to venereal diseases. We see this with AIDS today. AIDS kills through a mechanism very similar to that of The Plague, and those whose ancestors did not live though the Plague are ten times as likely to be affected by HIV as those from northern Europe.

The Plague did not cross the Pyrenees into Iberia, and apparently syphillis did not, either. In 1495, the first major outbreak of syphillis hit Europe, just at the same time that mercenaries from Spain, hired by France, hit Naples. That led to stories that Columbus brought back the disease from the New World.

Within a century of Columbus landing in Hispanola, the native population of north america dropped by 90%, due to diseases brought from Europe. Having never been exposed to these pathogens before, the native population was highly vulnerable.