Earliest known plague outbreak 5,500 years ago in Siberia

The earliest known outbreak of plague, dating back approximately 5,500 years, has been identified among prehistoric hunter-gatherers in Siberia, fundamentally altering scientific understanding of the disease's origins and lethality. A study published on June 17 reveals that ancient strains of the plague bacterium, Yersinia pestis, caused deadly epidemics in small, mobile communities long before the advent of agriculture and dense urban settlements.

Researchers analyzed ancient DNA from the remains of 46 individuals buried at four sites near Lake Baikal. They found evidence of Yersinia pestis infection in 18 of those individuals, a detection rate higher than that found in some medieval plague pits. The findings point to at least two separate outbreaks in the region, one around 5,500 years ago and another a few centuries later. Many of the victims were children and adolescents, with a particular susceptibility noted in children between eight and twelve years old.

The discovery challenges long-held assumptions that significant plague outbreaks only occurred after humans adopted farming and lived in high-density populations. It also contradicts the notion that early plague strains...