Archaeologists say they have found evidence for the oldest ever recorded Hepatitis B virus (HBV) in human history, as part of a broader project looking at human migration.
In papers published in both Nature and Science, teams sequenced the genomes of skeletons from humans stretching over a huge area, from Hungary to northeastern China, spanning about 8,000 kilometers (5,000 miles).
The large project was intended to produce a new genetic map of human migration across Eurasia. But in one of the papers, a team led by Professor Eske Willerslev from the University of Copenhagen in Denmark made an additional discovery that could reveal the origins of HBV.
They sequenced the DNA of more than 300 humans, stretching in time from 1,500 to 4,500 years ago, and found that 25 of these individuals had evidence for HBV infections, including strains that are now extinct, suggesting the virus was widespread across Eurasia and has evolved over time.
“This would be the oldest virus recorded,” Willerslev said in a press conference. “It’s very interesting because it allows you to address very fundamental questions about the evolution and development of this disease.”
Today, about 257 million people in the world are chronically infected with HBV. In 2015, around 887,000 people died from complications caused by the disease. How the virus began and evolved over time has been unclear, however.
Some think HBV co-evolved with humans as they left Africa 60,000 to 100,000 years ago, but the researchers noted in their paper that such an idea “has been contested”. While not seeking to solve that problem, this research does get us closer to an answer.