Hepatitis viruses have plagued humanity for millennia

Researchers find hepatitis B virus in Stone Age skeletons

Hepatitis B viruses, with more than 250 million infected people worldwide, are among the most common pathogens. The virus can cause severe liver inflammation, which in the worst case even ends in death. Hepatitis seems to be an old acquaintance of humanity. Apparently, Stone Age people were already plagued by hepatitis. Researchers at the University of Kiel recently discovered a strain of ancient hepatitis B viruses in studies of 7,000-year-old skeletons. Based on the samples, the scientists were able to understand the evolution of hepatitis.

An international team of researchers led by the Christian-Albrechts-Universität in Kiel (CAU) and the Max Planck Institute for the History of Mankind (MPI) in Jena found hepatitis B viruses in Stone Age human skeletons. The scientists succeeded in the reconstruction of the Stone Age viruses. These are strains of the hepatitis B virus (HBV). According to the results, it has circulated in Europe for at least 7,000 years. The research results were recently published in the journal "eLIFE".

The hepatitis virus has also changed

Although the viruses detected are similar to today's strains, but represent their own lineage dar. The researchers suspect that this is already extinct. Similar variants of the "stone-age hepatitis" occur today in chimpanzees and gorillas. Not much was known about the history and epidemiology of hepatitis. The researchers in Kiel have now succeeded in reconstructing viral stone-age DNA for the first time. This opened valuable information about the origin and evolution of the viruses.

A yellowing of the eye may indicate hepatitis. Apparently our ancestors already had to deal with the virus. (Image: y991bh / fotolia.com)

The oldest known virus so far

The scientists extracted the Stone Age viruses from dental samples of two Neolithic individuals. In addition, samples could be obtained from a medieval skeleton. This allowed the reconstruction of three hepatitis strains. The oldest strain is about 7000 years old and thus represents the oldest genetically proven viral pathogens so far.

The evolution of hepatitis B

The Stone Age pathogens are most similar to the hepatitis viruses found in human primates such as chimpanzees and gorillas today. In contrast, the medieval variant is more similar to today's tribes, but still represents its own lineage. The researchers report that the virus in the last 500 years has surprisingly little change. They suggest that multiple transmissions between humans and non-human primates occurred during the last 7000 years.

Relationship between lifestyle and virus outbreaks

"We examine whether there is a connection between the emergence of diseases and fundamental changes in the lifestyle of people in prehistory and early history," says the co-author of the Almut Nebel study in a press release from the University of Kiel on the study results. Thanks to modern methods, the researchers have been able to decode these relationships.

The possibilities of modern DNA research

"Since we started researching old human and pathogenic DNA at the CAU, a lot has happened," explains lead author of the study, Ben Krause-Kyora. New methods of analysis, such as proteomics, would broaden the range of methods to better study old diseases and the human genome in an archaeological and medical setting.

Big potential

"Our results show the great potential of aDNA (old DNA) derived from human bone," says Johannes Krause, director of the Department of Archaeogenetics at the MPI for Human History. The aDNA allows to study the evolution of blood-borne viruses. So far, it has always been doubtful whether it is possible to even detect such diseases from times past. Now there is a powerful tool to explore the multi-layered evolutionary history of viral diseases, Krause said. (Vb)