Melting glaciers could release long-frozen viruses to new hosts

In the Canadian High Arctic, climate change is bringing viruses and potential hosts together in new combinations, according to recent findings published research. Each novel interaction increases the risk of “viral spillover”, ie Pathogens jump to different hosts. And every overflow is an opportunity for a virus to become more dangerous.

Viruses rely on their hosts to replicate and spread, but most viruses co-evolve with the organisms that support them. Hosts develop defense mechanisms that viruses must overcome. But in cases of spillover – when a virus jumps over into a new life form – the hosts lack developed immunity. As with the Covid-19 pandemic, when a virus finds a new host for the first time, the consequences can be catastrophic.

In a glacier-fed lake in the high Arctic, more meltwater means a greater chance of viral spread, he says new study published in the journal Proceedings of the Royal Society B. The researchers took sediment samples from Lake Hazen, the world’s largest high arctic lake, and sequenced the viral RNA and DNA of animals, plants and fungi inside.

They found that in areas of the lake where glacial runoff is highest, the evolutionary overlap between viruses and possible host organisms is lowest. suggesting less shared history and more opportunities for unfortunate crossovers. And climate change is increasing runoff almost everywhere on Earth where there are glaciers.

Glaciers are ancient ice. Since they were thousands or tens of thousands of years ago (or even a million years ago) they became time capsules of their environment, trapping organic material, rock and pathogens in their matrix. And as a glacier (or permafrost) melt under climate change, they release the same things back into our rapidly changing world.

“This is further evidence that climate change is leading to more problems,” said the study’s lead scientist Stephane Aris-Brosoua computational biologist at the University of Ottawa, in a video call. The researcher said he was surprised that he and his fellow researchers found such a correlation between glacier runoff and spillover risk. But now that they have ithe wouldn’t be surprised if a new pandemic virus — be it a fungus, plant, or animal — emerges from glacial melt.

Although, Aris-Brosou carefully emphasized: “We do not predict the next pandemic‘ and certainly not the next major human virus explosion. The individual study of lake sediments is not a crystal ball. “We don’t predict when, where, in which host or which viruses will lead to the next pandemic – not something like that,” he says said.

Spillover events do not necessarily mean a pandemic, and the overwhelming majority of viruses do not infect humans. In addition, Aris-Brosou and his colleagues did not record the actual defection or even identify the specific viruses present in glacial sediment. Instead, they took a broad approach judge how much melting has mixed up various genetic stories in Lake Hazen.

Previous research has similarly found that climate change is one increase in chance of spillover events, soch as by forcing animals into other habitats. However, according to the study’s authors, the new study is the first of its kind to quantify the risk of spillover by sequencing all of the genetic data present in an environment. “To our knowledge, this is the first attempt to assess the full virosphere of both DNA and RNA viruses and their transmission capacity,” they wrote in their Paper.

As it is a new approach, Aris-Brosou pointed out that their results have major limitations. For one, there is no information to compare. The researchers were able to determine that spillover risk increases with glacial melt in the lake sediment, but they can’t tell how high the risk of viral spillover is in Lake Hazen compared to anywhere else in the world. “We have no sense of the scale at the moment,” said Aris-Brosou.

Also, because they sequenced such a large pool of genetic information, their results are not specific. Which viruses are lurking at the bottom of the lake, or even in what proportion, the scientists cannot say at the moment are still contagious. But in follow-up work that is already underway, Aris-Brosou wants to find out how closely the viruses found are related to today’s pathogens and if anyone is brand new to science at all.

Nonetheless, the results highlight a little –investigated side effects of climate change. By burning fossil fuels, we are changing everything in our world, right down to the interactions between life and viruses at the bottom of a glacial lake. “We are the main drivers of this situation,” said Aris-Brosou. And so, “We need to think carefully about how we live our lives.” Otherwise, there is an increasing risk of contagion and resulting future pandemics a consequence we have to live with.