Heating climate could increase risk of Arctic ‘virus spillover’

Scientists say water from melting glaciers is bringing together hosts and viruses that would not normally encounter one another.

A warming climate could bring viruses in the Arctic into contact with new environments and hosts, increasing the risk of “viral spillover”, according to newly published research.

Viruses need hosts like humans, animals, plants, or fungi to replicate and spread, and occasionally they can jump to a new one that lacks immunity, as seen with the COVID-19 pandemic.

Scientists in Canada wanted to investigate how climate change might affect spillover risk by examining samples from the arctic landscape of Lake Hazen.

It is the largest lake in the world entirely north of the Arctic Circle, and “was truly unlike any other place I’ve been”, researcher Graham Colby, now a medical student at the University of Toronto.

The team sampled soil that becomes a riverbed for melted glacier water in the northern summer, as well as the lakebed itself, which required clearing snow and drilling through two meters of ice, even in May — springtime in Canada — when the research was carried out.

They used ropes and a snowmobile to lift the lake sediment through almost 300 meters (980 feet) of water, and samples were then sequenced for DNA and RNA, the genetic blueprints and messengers of life.

But to find out how likely they were to jump hosts, the team needed to examine the equivalent of each virus and the host’s family tree.

“Basically what we tried to do is measure how similar these trees are,” said Audree Lemieux, the first author of the research.

Similar genealogies suggest a virus has evolved along with its host, but differences suggest spillover.

Agencies