Thawing permafrost exposes old pathogens—and new hosts

The northern part of the world is heating up quickly. It is warming four times faster than the rest of the world, with dire consequences for the region. Ice caps melting, sea levels rising, and polar bears losing their homes are some of the impacts you probably know about. Good news, but. There is a chance that the warming landscape could cause new pathogens to emerge.

Climate change will make the spread of infectious diseases worse. As the world warms up, many species are expected to up sticks and travel far away from their normal habitat, bringing with them diseases. This means that previously unacquainted viruses and hosts will meet for the first time, potentially leading to viral spillover.

And a part of the world where this has a good chance of happening is the Arctic. In a new paper published in the journal the Proceedings of the Royal Society B, a group of researchers from the University of Ottawa tried to quantify the spillover risk in the region. They went to Lake Hazen, a freshwater lake in Canada located inside the Arctic Circle, and took samples of the soil and lake sediment, before sequencing the genetic material in these samples to identify what viruses were present. They also sequenced the genomes of potential hosts in the area, including animals and plants. Advertisement

They wanted to know how likely it was that a new species would be invaded by a virus. They looked at the genetics of a virus and its typical host. If a host and a virus show similar patterns in how they have evolved, it suggests that they have lived together for a long time. If their patterns of evolution are different, it means the virus has spent time in other hosts, jumped before, and is more likely to do so again.

Knowing the propensity of viruses in the region to move species, they used a computer to estimate how climate change would affect the likelihood of them doing so They used the rising flow of meltwater off nearby glaciers as a proxy for rising temperatures and found that the risk of viruses in the area goes up with it. What's the reason? As meltwater streams into the lake, it carries and deposits silt, which unsettles the lake's population and, by disturbing this environment, speeds up pathogen evolution against their hosts' immune defenses.

It is not possible to give a conclusive answer on what will happen. Stéphane Aris-Brosou, an author on the paper and associate professor of biology at the University of Ottawa, says that they are not able to say that there are going to be serious Pandemic issues in the HighArctic. The work is just trying to figure out the risk of a spillover. It's not possible to predict this type of event.