[WayneS]

Paratyphoid fever spreads through food or water contaminated with the feces of a sick person. Today, it usually breaks out when people live in poor, crowded conditions. It’s possible that the Spanish, in addition to bringing the bacteria, relocated people and instituted agricultural practices that exacerbated its spread.

It is also "possible" that the existing culture and agricultural practices of the native peoples served to exacerbate the spread of the virus - assuming this particular virus is even the culprit.

[LesbianThespianGymnasticMidget]

It is bacterial, not viral.