Hunter-gatherers in Siberia died of a plague outbreak 5,500 years ago

Key Points:

• Researchers from the University of Oxford have identified the earliest known plague outbreak, dating back 5,500 years among hunter-gatherer groups near Russia’s Lake Baikal, through DNA sequencing of Yersinia pestis found in ancient teeth.
• This discovery challenges previous beliefs that plague became lethal only after humans began farming and living in dense settlements, showing instead that prehistoric mobile hunter-gatherer communities were also severely affected.
• The ancient strain of Y. pestis found lacks some genes associated with flea-borne transmission and buboes but was still highly deadly, particularly to children aged 7 to 11, likely due to a superantigenic toxin triggering severe immune reactions.
• Genetic and archaeological evidence indicates the plague spread through close human contact, probably via respiratory transmission, among interconnected family groups living along the Angara River, with burial patterns reflecting kinship ties.
• Understanding this ancient strain’s genetic makeup provides insights into the evolution of plague virulence and may help predict how similar pathogens could develop in the future.