The earliest known strain of the bubonic plague has been discovered in the body of a man buried in Latvia approximately 5,000 years ago. Research since the discovery has concluded that this strain materialized around 7,100 years ago and was not nearly as destructive as many of the other strains that devastated communities across the world. It was not as easily transmitted and much less harmful to the human body.
Researchers have discovered that this early strain did not provide the extreme and severely painful body boils which were a fatal component of the deadly virus. Ben Krause-Kyora, archaeologist and biochemist working at Kiel University in Germany, also uncovered that the strain did not spread via the flea-to-human transmission that made later variants so contagious. Instead this early strain appeared to spread from animals to humans through rodent bites.
Whilst this early version of the disease might not be as dangerous as its infamous successors, it can help scientists and researchers to uncover the evolutionary history of the bubonic plague, otherwise known as yersinia pestis. As this is the oldest known strain found to date, scientists are keen to gain a greater understanding of where the disease came from, and how and why it eventually evolved into the catastrophically destructive plague that killed millions.