Scientists crack hepatitis B puzzle

German scientists have found from Stone Age skeletons that pathogens behind the liver infection hepatitis B were present in Europe 7000 years ago.

The pathogens behind the liver infection hepatitis B were already doing the rounds in Europe some 7,000 years ago, German scientists have determined.

The genetic material of such viruses was found in Stone Age skeletons from the German state of Saxony-Anhalt, researchers at the University of Kiel reported.

The find marks the discovery of the oldest proven genetic viral pathogens.

More than 250 million people are infected with hepatitis B today, making it the most widespread virus in the modern world. It is spread by blood or during sex.

The findings were publicised in Thursday's edition of the professional journal eLIFE. Researchers from the Max Planck Institute for the Science of Human History helped with the work.

Researchers looked at 53 skeletons from later in the Stone Age, as well as some from the medieval period. In three of them, they found traces of hepatitis B and were able to recreate the genome.

There were differences in the genomes from the Stone Age and medieval ages, with the later ones closest in structure to the version of hepatitis B seen in modern times. Nonetheless, the virus has changed very little in the last 500 years.

Meanwhile, the Stone Age version has probably died out, though viruses related to it probably still exist in chimpanzees and gorillas. That said, there is no direct relation to the version plaguing modern man.