Genetic Study Reveals Oldest Plague Infection 5500 Years Ago

Researchers have managed to uncover the oldest genetic evidence of the presence of the plague bacteria, dating back 5500 years, through the analysis of DNA extracted from ancient human remains.

This discovery was part of an extensive study tracing the evolution of infectious diseases and their connection to major transformations in human history, such as the transition to agriculture and animal husbandry.

The study relied on the analysis of genetic samples taken from the bones and teeth of 1313 individuals who lived in Eurasia over 37,000 years, from the early Stone Age to modern times.

The results revealed the emergence of the first zoonotic diseases about 6500 years ago, with confirmation that their widespread occurrence began 1500 years later.

Professor Eske Willerslev from the universities of Cambridge and Copenhagen explained, "The transition to agriculture and animal husbandry opened the door to a new era of diseases," noting that these pathogens not only caused disease but also contributed to population collapses, mass migrations, and genetic adaptations.

In a significant discovery, the research team identified the oldest genetic trace of the Yersinia pestis bacterium, the causative agent of the plague, which later led to the deaths of between a quarter and half of Europe's population during the Middle Ages.

Researcher Frederik Seersholm from the University of Copenhagen commented on this discovery, saying, "It is the oldest case of plague found to date," adding that this discovery shows the historical evolution of the plague until it reached its destructive form known as the 'Black Death'.

The study also revealed the presence of other diseases in prehistoric times, including diphtheria dating back 11,000 years, hepatitis B virus infection 9800 years ago, and malaria 4200 years ago.

Professor Astrid Iversen from the University of Oxford pointed out that zoonotic diseases had a wide spread about 5,000 years ago, with the evolution of animal husbandry practices and living in close proximity to animals.

These results were part of a study published in the journal 'Nature' on Wednesday, July 9, highlighting the pivotal role of infectious diseases in shaping the course of human history.