Deadly Salmonella Outbreak Causes The Aztec Empire Downfall

A new DNA evidence shows that the deadly outbreak of salmonella causes the collapse of the Aztec empire in the 1500s in Mexico. During that era, Aztec's population was about 25 million. Yet following many deadly outbreaks, they plummeted into 1 million within a century of the 1519 arrival of the Spanish conquistadors.

Aztec society was a highly complex society that composed of the Aztecs of central Mexico. It was divided between nobles and free commoners based on the hierarchies of social status, responsibilities and power. Most of the Aztecs were dependent on agriculture, warfare, the high degree of trade specialization and commerce.

The basic units of Aztec society were family and lineage. An Aztec lineage was determined by one's social standing. Meanwhile, the noble lineages were considered they descended from the god Quetzalcoatl.

In the new study, the researchers examined the fragments of DNA from the teeth of 29 bodies buried in the Oaxacan highlands Mexico after an outbreak during the 1550s. They identified evidence of the salmonella strain from those fragments.

According to Science Alert, the researchers separated bacterial DNA from the DNA of the humans. They compared the results with over 2,700 modern bacterial genomes and discovered that many people they had tested were infected with a deadly strain of Salmonella enterica, also referred to as Salmonella Paratyhi C.

Currently, the Paratyhi C could still appear yet very rare particularly in the developing world. It is spread through fecal matter and has symptoms like enteric fever, which is a typhus-like disease. It can be treated; however, without medication, it could kill 10 to 15 percent of the infected people.

The researchers concluded that Salmonella Paratyhi C contributed to the decline of the population of the Aztec society during the 1545 cocoliztli outbreak in Mexico. The 1545 cocoliztli epidemic is considered one of the most devastating epidemics in New World history.