This Giant Virus Is Back After 300,000 Years

Researchers have unearthed a gigantic virus buried in Siberian permafrost for 30,000 years, sparking fears that climate change and human behavior could prompt a revival of previously-extinct pathogens. (Thanks, global warming!) But don't panic just yet: The Pithovirus, this first member of a brand-new virus family, poses no threat to humans and animals and infects only single-celled organisms.

The team of French and Russian researchers took 30,000-year-old samples by drilling horizontally into Siberian ice, and discovered the Pithovirus. It resembles the Pandoravirus, which is one of the largest viruses ever found. The pathogen existed around the same time as the extinction of Neanderthals, and replicates in a way similar to the way large DNA viruses reproduce.

While the term "giant" may spark fears of a looming apocalypse, the pathogens are microscopic and invisible to the naked eye. Still, this new finding is monumental, since the Pithovirus has almost nothing in common with giant viruses previously discovered, aside from its size and shape. Scarily, researchers Jean-Michel Claverie and Chantal Abergel, who took part in the study, found that after exposing the permafrost samples to amoebas, the virus was still able to burst organisms open and kill them.

This unearthing has larger implications for public health risks: If these viruses can survive in frozen layers of soil over geologic time periods, mining and drilling companies could potentially accidentally release the pathogens. In their report, researchers forecasted that "the re-emergence of viruses considered to be eradicated, such as smallpox... is no longer the domain of science fiction."

As if that wasn't enough to make you quake in your boots, climate change might also lead to ice thawing and a resurgence of said pathogens. Good job, global warming!

So, the big question: Are we in danger of unleashed, ancient viruses wreaking havoc in our present-day environment? Some experts say that though the situation is unlikely, it's feasible.

The team responsible for discovering the Pithovirus will further their research to examine how real of a threat these early pathogens pose. Until then, we'll be hiding under the covers if you need us.

Image: CNRS press release