A team from the Hebrew University of Jerusalem and Seoul National University carried out a liver biopsy of the mummy and found a unique hepatitis B virus (HBV) known as a genotype C2 sequence, which is said to be common in Southeast Asia, LiveScience reported.
Carbon tests of the clothing of the mummy suggested that the mummified boy lived around the 16th century when Joseon Dynasty was ruling in Korea, the researchers said.
The viral DNA sequences recovered from the liver biopsy enabled the scientists to map the entire ancient hepatitis B viral genome, they said.
Using modern-day molecular genetic techniques, the team compared the ancient DNA sequences with contemporary viral genomes disclosing distinct differences. The changes in the genetic code are believed to result from spontaneous mutations and possibly environmental pressures during the virus evolutionary process.
Based on the observed mutations rates over time, the analysis suggests that the reconstructed mummy's hepatitis B virus DNA had its origin between 3,000 to 100,000 years ago.
Additional analysis of the ancient HBV genomes may be used as a model to study the evolution of chronic hepatitis B and help understand the spread of the virus, possibly from Africa to East-Asia, the researchers said.
It also may shed further light on the migratory pathway of hepatitis B in the Far East from China and Japan to Korea as well as to other regions in Asia and Australia where it is a major cause of cirrhosis and liver cancer, they reported in the journal Hepatology.
The hepatitis B virus is transmitted through the contact with infected body fluids, including from mothers to their babies, through sexual contact and intravenous drug abuse.
According to World Health Organisation, there are over 400 million carriers of the virus worldwide, predominantly in Africa, China and South Korea, where up to 15 per cent of the population are carriers of the virus.
