Razed by rodents?

• Author: Hardman, Chris
• Position: Native South American population

The Spanish have long been blamed for the downfall of the Aztec Empire. The invaders brought with them diseases such as smallpox, measles, and mumps, which decimated the Indian population. Now after more than a decade of research, Mexican epidemiologist Rodolfo Acuna-Soto, of the Universidad Nacional Autonoma de Mexico, proposes that the one disease that killed more of the Indian population that any other was caused by hemorrhagic fevers spread by native rodents--not marauding Spaniards.

During sixteenth-century Mexico, a new and virulent disease rampaged through the native population of the Mexican highlands. The first wave lasted from 1545 to 1548 and killed five million to fifteen mililon people--80 percent of the Indian population at that time. Successive outbreaks from 1576 to 1578 killed an additional two to two-aid-a-half million people, or about 50 percent of the remaining Indian population. Acuna-Soto identifies this episode as "one of the worst demographic catastrophes in human history." Remarkably, the Spanish population seemed to be only marginally affected.

The disease was called cocoliztli, which meant pestilence in the Nahuatl language, and according to Acuna-Soto's research, neither the Aztec nor the European doctors had ever encountered the disease before. According to graphic descriptions front Franciscan historians and Spanish physicians, the illness generally lasted three to four days and included fever, profuse bleeding, dysentery, severe pain, and acute neurological disorders. One friar wrote that because so many people were dead and dying, the priests spent all their time digging trenches and filling them with bodies. After studying the accounts of the epidemic, Acuna-Soto suspected that the illness was a form of hemorrhagic fever--a viral disease like Ebola that comes on quickly, kills easily, and resists medical treatment.

In his review of the Aztec's historical documents, Acuna-Soto noted that the cocoliztli outbreaks were always followed by...