Normally, the Classic period in Mesoamerica is characterized as the stage in which the arts, science, urbanism, architecture, and social organization reached their peak. This period was also dominated by the influence of Teotihuacan throughout the region, and the competition between the different Mesoamerican states led to continuous warfare.
The most common name for the killer virus, the Spanish flu, implied, of course, that it originated in Spain. Perhaps this was because there were serious outbreaks in both Madrid and Seville that infected eight million people in May of 1918 alone, even almost taking out the king himself, Alfonso XIII.
By an examination of preserved tissue, the worst influenza pandemic (also termed the Spanish flu or Spanish influenza) occurred in 1918 when the virus caused between 40-100 million deaths worldwide, with a mortality rate estimated to range from 2%-20%.