Reemerging Pathogens: Ancient viruses survive in glaciers

Reemerging Pathogens: Ancient viruses survive in glaciers

The recent United Nations Conference on Climate Change put global warming and its potential impact on the earth front and center. It has been long understood that the ice caps are melting; and world leaders are actively looking for ways to limit pollution, greenhouse gasses and other environmental foes to prevent irreversible damage. However, as the ice caps continue to recede there is one component that should also be considered, viruses. What’s surprising is what may be unearthed as the ice melts, suspended for tens of thousands of years. No, not woolly mammoths or sabertooth tigers, but an equally-astounding virus much larger than its modern relatives.

According to the BBC, in 2014 scientists discovered a 30,000-year-old virus that had reanimated after thawing out from under 100 feet of Siberian permafrost. Researchers said it was the first time they’ve seen a virus remain infectious after that length of time and they continue to confound the scientific community.  Experts can’t even agree on whether or not a virus should be truly considered a living thing, like bacteria and larger life forms, though recent research has scientists leaning toward “yes.” But even if viruses are to be considered living, they still occupy a strange, ancient space in the evolutionary realm. That is to say, they are completely unlike any other entities on Earth – living or not.

For starters, viruses tend to be much smaller than your typical single-celled bacteria – we’re talking a fraction of the size. That allows viruses to invade a cell and essentially hijack its tools, using it to perform the virus’s bidding. On their own, viruses have difficulty surviving, let alone reproducing. That’s why they’re designed to occupy cells and turn them, in many cases, into vectors for disease. Scientists now mostly agree that viruses belong on the tree of life, albeit near the base – before bacteria or other organisms long thought to be the precursor to all living things, according to Discovery News.

“Viruses are living,” confirmed Arshan Nasir, a University of Illinois graduate student who worked on a study with the Carl R. Woese Institute for Genomic Biology. “They simply have an atypical mode of living that is slightly different from ours. They are not fully independent. Instead, they move in and out of our bodies, stealing the resources and producing their offspring. In short, we need to broaden how we define life and its associated activities.”

But that isn’t the only notion about viruses that’s been changing. Recent discoveries opened up even more possibilities for the microscopic entities.

What's hidden beneath the glaciers?
What’s hidden beneath the glaciers?

Massive viruses resurface after being trapped in the ice caps
The virus recently unearthed from under 100 feet of Siberian permafrost can only infect and kill amoebas. Researchers said it was the first time they’ve seen a virus remain infectious after that length of time.

“It was the first time researchers have seen a virus remain infectious after so long.”

Though it can infect and kill amoebas, Pithovirus sibericum poses no threat to human cells. Still, the possibility for ancient viruses to survive deep within the ice sheet could mean worse things are lurking further down. As humans explore and drill into the frost, they might unwittingly release more dangerous primeval viruses – including one that is all too familiar.

“If it is true that these viruses survive in the same way those amoeba viruses survive, then smallpox is not eradicated from the planet – only the surface,” Professor Jean-Michel Claverie, from the National Centre of Scientific Research in France, told the BBC. “By going deeper we may reactivate the possibility that smallpox could become again a disease of humans in modern times.”

Disinfection efforts must remain strong

In the event there are, indeed, more deadly viral foes living beneath the Siberian tundra, then any team venturing into that region must exercise caution. As the tundra recedes, the region will be more accessible to human endeavors, like drilling or industry. If and when that happens, organizations must have protocols in place to prevent diseases and hidden viruses from escaping and causing an outbreak.

Read more about other emerging pathogens that are under strict surveillance.