Scientists revive ancient virus

MELTING ice caps could release an unexpected threat - in the form of ancient viruses long thought extinct, French scientists have warned.

Researchers have discovered one such virus - “pithovirus sibericum” - in a sample of permanently frozen soil taken from coastal tundra in Chukotka, in Eastern Siberia.

The team thawed the virus, which had been buried 30m under ground and watched as it replicate in a culture in a petri dish and infected an amoeba.

It had been buried for 30,000 years.

The virus, which poses no danger to humans or animals, is so large it can be seen under a microscope.

‘This is the first time we’ve seen a virus that’s still infectious after this length of time,’ said Professor Jean-Michel Claverie, from France’s National Centre of Scientific Research, which is based in Marseille.

The discovery has raised fears that other, more deadly, pathogens such as smallpox could be released from the frozen ground.

He warned: “The demonstration that viruses buried in the ground for more than 30,000 years can survive and still be infectious suggests that permafrost melting due to global warming and the mining and industrial exploitation of the Arctic may pose a risk to public health.

"The revival of viruses that are considered to have been eradicated, such as the smallpox virus, whose replication process is similar to that of pithovirus, is no longer limited to science fiction.

"The risk that this scenario could happen in real life has to be viewed realistically."

One expert said drilling deeper in the region, which researchers say is under threat as the ice thins, is a “recipe for disaster”.

Dr Chantal Abergel, the co-author of the report published in the journal Proceedings of the National Academy of Sciences, said the team was taking every precaution to stop other viruses being released.

Picture: Julia Bartoli and Chantal Abergel