Aztecs wiped out by ravaging eye-bleeding disease

Scientists believe Mexico’s Aztecs were wiped out by a grisly disease that caused bleeding from the eyes, nose and mouth.

Up to 15 million people are believed to have died when the epidemic - known as cocoliztli – swept through the ancient civilisation from 1545.

The term means “pestilence” in the Aztech native Nahuatl language.

Its cause has proven a burning question for scientists and historians for 500 years, with influenza, mumps, measles and smallpox long suspected.

But there was a breakthrough this week when a study by researchers from the University of Tuebingen in Germany and published in Nature Ecology & Evolution pinpointed “enteric fever”.

Researchers says its symptoms mirror contemporary descriptions of victims developing red skin spots and bleeding from various bodily orifices including the eyes, nose and mouth.

The study was based on DNA analysis of the teeth from 29 Aztec skeletons using new software that can detect any known pathogen.

It found traces of the salmonella enterica bacterium, of the Paratyphi C variety.

Historians say its impact on the Aztec population from 1545 to 1550 was devastating, with a death rate of 90 per cent.

"What we're talking about is the devastating decimation of indigenous populations by previously unknown diseases," Dr Caroline Dodds Pennock, lecturer in international history at the University of Sheffield, in the UK, told The Independent. 

"Mortality rates were maybe 80 or 90 per cent by 1600," she said. "Imagine nine out of every 10 people dying - it's almost unimaginable."