Earliest Evidence of Plague Uncovered from 5,500 Years Ago

Researchers have discovered the oldest known evidence of the plague, dating back nearly 5,500 years, predating previous estimates by about 200 years. This deadly disease has impacted humans for millennia, wiping out significant portions of Europe’s population in the 14th century during the Black Death. Though rare, the plague still exists today and is treatable with antibiotics.

Eske Willerslev, an evolutionary geneticist from the University of Copenhagen, emphasized the importance of understanding the plague’s history to comprehend human history better. Willerslev and fellow researchers searched for plague-causing bacteria traces in skeletal remains from four cemeteries near Siberia’s Lake Baikal. They found plague DNA in the teeth of 18 ancient hunter-gatherers, with carbon dating of the bones revealing two outbreaks, the earliest occurring around 5,500 years ago.

The study identified that this prehistoric plague developed gradually and spread among small family groups. It likely transferred from marmots, large native rodents, when people consumed raw organs or handled infected skins. The disease also spread between individuals through coughing and sneezing, the authors noted.

Many victims were children aged 8 to 11 years. Three girls were buried together, with two of them probably being cousins. The study found a burial of an aunt and her nephew together, while her niece was in a separate mass grave. Ruairidh Macleod, who studies ancient DNA at the University of Oxford, highlighted the human element in the scientific work, as those who buried the dead knew the identities of the deceased.

The research indicated that children faced higher risks due to weaker immune systems. The presence of multiple victims suggests that the prehistoric plague caused both individual cases and outbreaks, explained Aida Andrades Valtueña, a geneticist from the Max Planck Institute for Evolutionary Anthropology, who was not involved in the study.

Findings revealed that this type of ancient plague evolved long before the bubonic plague responsible for the Black Death in medieval Europe. Yet, earlier plagues were equally deadly, affecting not only crowded cities but also small nomadic hunter-gatherer groups. Understanding the plague’s evolution offers insights into how pathogens may emerge in the future.

This research receives support from the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation. The Associated Press holds sole responsibility for its content.