Oldest Evidence of Plague Found

Scientists have uncovered the oldest known evidence of the plague. This discovery dates back nearly 5,500 years, 200 years earlier than previously thought. The disease has impacted humans for millennia and significantly reduced 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 at the University of Copenhagen in Denmark, emphasized the importance of understanding plague history to comprehend human history fully. Willerslev and his team searched for traces of plague-causing bacteria in remains from four cemeteries near Lake Baikal in Siberia. They found DNA traces of the plague in the teeth of 18 ancient hunter-gatherers. Carbon dating of the bones revealed two outbreaks, with the earliest cases dating back 5,500 years.

The research found that the prehistoric plague evolved in stages and infected several small families. It likely spread from marmots, large native rodents, as people consumed raw organs or touched infected skins during butchering. The disease also transmitted from person to person through coughs and sneezes, the authors noted.

Many of the deceased were children between 8 and 11 years old. Three girls were buried next to each other, with two probably being cousins. The study published in the journal Nature showed an aunt and her nephew buried together, while her niece was in a separate grave. The work highlighted a human element, as people buried the dead knowing them personally, explained the study co-author Ruairidh Macleod, a researcher of ancient DNA at the University of Oxford.

Researchers suggested children faced higher risks due to weaker immune systems. The presence of multiple victims indicates that prehistoric plague could cause both isolated cases and outbreaks, according to geneticist Aida Andrades Valtueña from the Max Planck Institute for Evolutionary Anthropology, who was not part of the study.

This ancient form of plague evolved long before the bubonic plague responsible for the medieval Black Death. However, evidence shows earlier plagues were equally lethal. The disease devastated both crowded cities and small groups of nomadic hunter-gatherers.

Andrades Valtueña stated in an email that understanding these early plague stages helps uncover how the bacteria became the deadly pathogen known today. Such insights could provide clues on the emergence of future pathogens.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science Education Department and the Robert Wood Johnson Foundation. AP is solely responsible for all content.