The public was appalled by this scourge. Physicians too, von Hutten reported, were so revolted that they would not even touch their patients.

The idea of infection began to be taken far more seriously than it ever had before. Hospitals transformed themselves in response to the new plague - sometimes for the better, but often for the worse, as when, in fear, they cast their ulcerated patients out into the streets.

Hospitals in early modern Europe were charitable institutions, designed to provide care and shelter to the sick poor.

Perhaps more than any other disease before or since, syphilis in early modern Europe provoked the kind of widespread moral panic that AIDS revived when it struck America in the 1980s.

Was this an old disease, and, if so, which one? If it was new, what did that say about the state of medical knowledge? And in any case, how could physicians make sense of it?

Medical research in the twentieth century mostly takes place in the lab; in the Renaissance, though, researchers went first and foremost to the library to see what the ancients had said.

Even more than this, however, the sick - like lepers - were often reviled because people believed that they had brought their torments upon themselves.

Regardless of its geographic origin, people quickly began to notice that the pox traveled from one person to another. They sometimes blamed transmission on common and morally innocuous practices - drinking from a common cup, kissing friends in church, following a syphilitic comrade on the latrine.

Often, city fathers blamed prostitutes for the disease, and some threatened to brand their cheeks with hot iron if they did not desist from their vices.