Thawing permafrost due to climate change may unleash a host of ancient viruses, according to a team of European researchers who say they found 13 previously unknown pathogens trapped in vast Russia’s frozen ground. Siberian region.
Scientists found a virus they estimate washed up under a lake more than 48,500 years ago, highlighting a potential new threat from a warming planet: what they dub “zombie” viruses. The same team as French, Russian, and German researchers previously isolated ancient viruses from permafrost and published their findings in 2015. This concentration of new viruses suggests that such pathogens are likely more common on the tundra than previously thought,
as suggested in a preliminary study they published last month on the BioRxiv website. In this portal, many scientists share their research before they are included in a scientific journal. “Every time we look, we find a virus,” said Jean-Michel Claverie, study co-author, and fellow emeritus. Professor of Virology at the Aix-Marseille Université in France, in a telephone interview. “It’s a done deal.
We know that whenever we look for contagious viruses in the permafrost, we will find one.
Although the viruses they studied were only contagious to amoebas, the researchers said there was a risk that other viruses trapped in permafrost for millennia could spread to humans and other animals. Virologists not involved in the research said the specter of future pandemics emanating from the Siberian steppe is low on the list of current public health threats. Most new or old viruses aren’t dangerous, and those that survive,000 years of deep freezing typically don’t fall into the category of coronaviruses and other highly infectious viruses that lead to pandemics, they said. The results of the European team have yet to be peer-reviewed. However, independent virologists said their results appeared plausible and were based on the same techniques that have produced other results examined.
Several scientists said the risks of suppressed viruses in the Arctic should be monitored, there is a chance that they will be reinfected. Other categories of viruses, like the coronaviruses that cause Covid-19, are more fragile and less likely to survive freezing. Siberian permafrost is the largest natural freezer known to exist, according to a virologist and department head of pathobiology and veterinary sciences at the University of Connecticut, Paulo Verardi. And when the pathogens are frozen in humans or animals, “that can be a little worrying.” said he.
But, he said, “when you do the risk assessment, it’s very low,” he added. “We have a lot more to worry about at the moment. For the most recent investigation, the European team took samples from various locations in Siberia over several years, starting in 2015. The viruses they found, of an unusually large species that infect amoebas, were last active thousands and, in some cases, tens of thousands of years ago. Some of the samples were in the ground or rivers, although one of
viruses that targeted amoebas were found in the remains of a frozen intestine of a Siberian wolf dating back at least 27,000 years, the team said.
The researchers used amoebas as “virus decoys” because they thought it would be a good way to look for viruses without spreading viruses that could spread to animals or humans. But they said that doesn’t mean these viruses didn’t exist in the tundra.
On average, Siberia is warming four times as quickly as the rest of the world. In recent summers, it has been hit with wildfires and temperatures reaching 100 degrees Fahrenheit. And its permafrost, so cold it stays frozen even in summer, is thawing quickly. This means that organisms trapped for millennia are now being uncovered as long thawing at the soil surface allows trapped objects below to rise to the top.
Researchers say the likelihood of people encountering human or animal carcasses is increasing, particularly in Russia, whose parts of the far north are more densely populated than the arctic regions of other countries. The team collected some of their samples in Yakutsk, a regional capital and one of the fastest-growing cities in Russia due to the mining boom.
The warming of the permafrost has previously been blamed for the outbreak of infectious diseases. A 2016 anthrax outbreak hit a remote Siberian village and was linked to the carcass of a 75-year-old reindeer that had emerged from the frozen ground. But anthrax, which isn’t a virus, isn’t unique to Siberia and is unlikely to cause widespread pandemics. Many virologists say they are more concerned about the viruses currently circulating among humans than the risk of unusual permafrost viruses. New microbes are popping up or re-emerging all the time, Anthony S.
Fauci, director of the National Institute of Allergy and Infectious Diseases, told The Washington Post in 2015 when the first results from permafrost researchers appeared.
“It’s a fact of our planet and existence,” he said. “Finding new viruses in the permafrost isn’t much different from any of this. Its relevance will depend on an unlikely sequence of events: the permafrost virus must be able to infect humans, then it must [cause disease], and it must be able to spread efficiently from one human to another. That can happen, but it is very unlikely. More problematic, say many virologists, are the viruses that infect humans and cause diseases that are sometimes difficult to control, such as Ebola, cholera, dengue fever, and even the common flu.
Viruses that cause disease in humans are unlikely to survive the repeated cycle of thawing and freezing occurring on permafrost’s surface. And the spread of mosquitoes and ticks, linked to global warming, is more likely to infect people with pathogens, some experts say.
An extinct virus “appears to be a low risk compared to the large number of viruses circulating among vertebrates around the world that have proven to be a real threat in the past, and where similar events occur in the future, we still lack a framework to detect them early,” said Colin Parrish, a virologist at Cornell University who is also president of the American Society for Virology.