About this Episode: The smallpox virus had its greatest impact on the Indian populations in what is now Central and South America. Some historians have theorized that “it was not Cortez’ soldiers but smallpox that conquered the kingdom of the Aztecs in Mexico in 1520.” While this might be an exaggeration, smallpox certainly took its toll. It’s no wonder that the “Aztecs couldn’t believe that such a disease could be considered small and called it the `big pox.’“

The psychological impact of smallpox was also great. Between 1518 and 1531 nearly one-third of the total Indian population died of smallpox while the Spanish remained mysteriously unaffected. The Indians interpreted this to mean that their gods had failed them. In a deeply religious and superstitious society this assessment undermined the will to resist and made it possible for the Spanish to conquer what was left of the well-established pagan Aztec population.

Smallpox was followed by waves of measles, influenza, and typhus. “By the end of the sixteenth century, it is estimated that up to 90 percent of the indigenous populations had died in the successive waves of disease, and the Spanish began importing slaves to meet the labor demands created by catastrophic disease mortality.” The Aztecs contributed to their own demise through human sacrifice. As many as fifty thousand people a year were sacrificed “as a gourmet source of protein for its privileged elites.” But, that’s another story for another time.