Researchers have found evidence of the earliest known plague epidemic.

Researchers detected and reconstructed the genome of the Yersinia pestis bacterium from remains buried in an ancient burial site in southeastern Siberia, dating back over five thousand years. This is possibly one of the earliest known evidence of human infection related to the plague. In an article published in the journal Nature on the 17th, they stated that archaeologists have been excavating four ancient burial sites around Lake Baikal in recent decades. These burial sites contain the remains of hunter-gatherers who died four to five thousand years ago. Previous theories suggested that hunter-gatherer groups were small and mobile, and therefore would not experience large outbreaks of infectious diseases within their communities.