Humans have been battling viruses since well before the wheel was invented.  According to archaeologists, a fast moving epidemic roughly 5,000 years ago wiped out a prehistoric village in what is today northeastern China.  Dead bodies were stuffed inside a dwelling – the Hamin Mangha – that was later burned down.

Another mass burial, the Miaozigou site, took place about the same time and in the same general area.  Together these discoveries suggest there was a rapid outbreak of an acute infectious disease.  An epidemic ravaged the entire region.

The viral spread of submicroscopic pathogens has the potential to alter the flow of history.  Soldiers returning to the Roman Empire after war against Parthia in 165 AD brought back more than the spoils of conquest.  The Antonine Plague, which is suspected to have been smallpox or measles, claimed an estimated 5 million lives.  The epidemic had devastating consequences throughout the Roman Empire; perhaps bringing forward the demise of Pax Romana.

About 1,350 years later Spanish forces, led by Hernán Cortés, delivered the gift of smallpox as they conquered the Aztec capital of Tenochtitlán.  About a decade after, Spanish conquerors spread the plague to the Incas.  An estimated 90 percent of the native population was killed off by the pestilence.  Aztec and Inca civilizations were swiftly wiped off the map and replaced by New Spain.