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Scientists find oldest trace of plague bacterium from 5,500 years ago
The earliest evidence of zoonotic diseases - illnesses transmitted from animals to humans - dates back to about 6,500 years ago and became more widespread about 1,500 years later.
20 Jul 2025 08:00pm
A computer screen shows a human skull in a laboratory. (Photo by Roland DE COURSON / AFP)
COPENHAGEN - A large-scale study of human disease dating back 37,000 years of harmful bacteria, viruses, and parasites that have afflicted humans for millennia has revealed that the first evidence of the plague bacterium occurred some 5,500 years ago, reported German Press Agency (dpa).
The study mapped an entire catalogue of infectious diseases by analysing DNA of bones and teeth from 1,313 individuals who lived across Europe and Asia (Eurasia) from the Early Stone Age, around 12,500 years ago, to about 200 years ago, with the oldest sample dating as far back as 37,000 years ago. The study detected the world's oldest genetic trace of Yersinia pestis, the plague bacterium, in a sample dating back 5,500 years. The plague is estimated to have killed between one-quarter and one-half of Europe's population during the Middle Ages. - AFP file photo for illustration purpose only
The researchers found that the earliest evidence of zoonotic diseases - illnesses transmitted from animals to humans - dates back to about 6,500 years ago and became more widespread about 1,500 years later.
"We've long suspected that the transition to farming and animal husbandry opened the door to a new era of disease. Now, DNA shows us that it happened at least 6,500 years ago," said Professor Eske Willerslev, from the universities of Cambridge and Copenhagen.
"These infections didn't just cause illness - they may have contributed to population collapse, migration, and genetic adaptation."
The study detected the world's oldest genetic trace of Yersinia pestis, the plague bacterium, in a sample dating back 5,500 years. The plague is estimated to have killed between one-quarter and one-half of Europe's population during the Middle Ages.
It also found traces of diphtheria going back 11,000 years, hepatitis B going back 9,800 years, and malaria 4,200 years ago. In total, researchers identified 214 known human pathogens in prehistoric humans from Eurasia.
The study was published in the journal Nature on Wednesday. - BERNAMA-dpa
