As climate warms, snow-trapped viruses may find new hosts, study finds

With rising temperatures, viruses that have been preserved in ice until now may re-emerge. According to a study published in the Journal of Royal Society Biological Research Actions bWednesday, October 19,Global warming may be a cause “Virus Overflow” from the Arctic, by allowing viruses to interact with new hosts in other environments.

Humans, animals, plants, algae… As shown by the recent Covid-19 pandemic with humans, viruses use them to replicate and spread.

“The probability of dramatic events is extremely low.”, explains the study’s first author, Audrey Lemieux of the University of Montreal. But according to the Canadian researchers behind the work, the risk may increase with continued global warming: new hosts may move into previously inhospitable areas. There is a possibility of overflow “Totally unpredictable, and its consequences range from innocuous to truly epidemic,” The scientist insists.

Canadian scientists investigated whether climate change could favor such a scenario in the Arctic environment of Lake Hazen, Canada’s largest lake beyond the Arctic Circle. During the summer, when the snow melts, they take samples from the bottom of the lake and from the bed of the river that feeds it. By analyzing the sediments, “This allowed us to determine which viruses were present and which potential hosts were present in a given environment“, explained to AFP Stephen Aris-Brousseau, associate professor in the Department of Biology at the University of Ottawa, who oversaw the study.

The team then set out to find out how susceptible viruses are to changing hosts by looking at the equivalents of their respective family trees. And for good reason: Similar genealogies suggest that the virus evolved with its host, while differences indicate that it may have switched hosts. And if he’s done it once, he’s likely to do it again. However, the analyzes showed great differences in the family trees of the viruses and their hosts in the sediments extracted from the bottom of the lake.

However, these differences were less pronounced in the river bed feeding the lake. The researchers speculate that meltwater from glaciers erodes bed sediments, thereby limiting interactions between viruses and potential hosts. On the other hand, the rate of melting of the glaciers feeding the lake has also increased the amount of sediments transported there. “It’s going to interact with hosts and viruses that normally wouldn’t interact” Audrée Lemieux noted.

In 2016, the anthrax bacterium, the cause of anthrax, reappeared in Siberia, threatening the semi-nomadic people who occupy this inhospitable tundra.