In the summer of 2016, a heatwave washed over Europe, thawing permafrost in the north. In the Arctic soil of Siberia, bacteria began stirring—anthrax, to be specific. The thawing, shifting ground exposed a reindeer carcass buried and frozen in 1941. The anthrax spores from the body found their way into the top layer of soil and the water nearby, before being picked up by thousands of migratory reindeer grazing in the area. Over two thousand reindeer soon contracted the deadly bacteria and passed it along to the nomadic Nenets peoples who travel alongside the reindeer and depend upon them for food. By the end of August, a 12-year-old boy had died, and at least 115 others had been hospitalized.
The current coronavirus pandemic, despite likely originating with an animal-to-human crossover far from the Arctic Circle, has come at a particularly weighty moment for infectious disease. As the Arctic warms twice as fast as the rest of the world, its ground is starting to thaw. With that thaw, bacteria and viruses once buried in the permafrost could increasingly emerge from a long hibernation. At the same time, the Arctic is seeing more traffic than ever, with sea routes opening up and natural resource exploitation growing in the region. As microbes begin reemerging, they have more opportunities than ever to encounter people and animals.
It’s not just bacteria like anthrax making a reappearance. The Arctic is no stranger to deadly viruses, as well. The bodies of victims of the 1918 influenza pandemic, to which many are now comparing the current coronavirus pandemic, are still buried in the Arctic permafrost. And centuries after smallpox raged through Siberian settlements in the 1890s, the bodies of those buried along the now-eroding Kolyma River have begun resurfacing.
Researchers have also discovered viruses never before recorded, like the recently christened “pandoraviruses,” lurking in the permafrost. Pandoraviruses are a type of giant virus that appear to have been more common about 30,000 years ago. In 2014, researchers successfully revived two of these ancient viruses, which were found 100 feet underground in tundra along the coast. Luckily for us, the viruses can only infect single-celled amoebas, not people. But other unknown viruses and bacteria could potentially spread to humans after being preserved for hundreds or even thousands of years within Arctic ice. Without the immunity our ancestors may have had, both humans and the intermediary animals that can spread diseases could be extremely vulnerable to the revived microbes.
So far, few of the viruses recovered from the permafrost seem to be active or contagious. In the bodies from the 1890s smallpox outbreak, for example, researchers were able to find some viral material to confirm that the people had indeed died of the virus, but they did not find completely intact viruses that would have been contagious. Attempts to cultivate other permafrost viruses in laboratories have largely failed.
Some hardy bacteria, on the other hand, seem to be just as potent as when they were buried. Not all bacteria can survive the harsh conditions of the Arctic for long periods of time, but a few—like anthrax, tetanus, and the bacteria that causes botulism—can.
These bacteria are not limited to the Arctic permafrost, of course. “Obviously, dirt everywhere is potentially a problem,” Anne Jensen, a senior scientist for Ukpeavik Iupiat Corporation Science LLC and an archaeologist based in Utqiagvik, in Alaska’s far north, told me. “I mean, it could be a problem in New York State. There’s a lot of places [where] dirt’s got botulism in it. There’s a reason why if there’s a puncture wound and it’s dirty, you go get a tetanus shot.”
Anthrax, for example, occurs naturally in the soil all over the world. In fact, it tends to thrive in warmer climates—which may be part of why it began spreading again during the heat of the 2016 Siberian summer—but it’s far from a prehistoric disease brought back to life by climate change. Rather, climate change is creating better conditions for it to continue thriving, said Jason Blackburn, an associate research professor and associate professor of geography at the University of Florida’s Emerging Pathogens Institute.
“We may see a longer growing season in the northern habitat, so we may see those anthrax seasons become longer,” Blackburn told me. “The seasons might begin earlier as the green-up begins earlier—and hotter, longer seasons. We may see more areas opening up to agriculture or livestock than we have currently.” Blackburn said it’s possible that, in a changing climate, the Siberian reindeer and their herders in 2016 were taking a different migration route—one that had once been off-limits because of a historic knowledge of the presence of anthrax but that made more sense given changes to the land during the heatwave.
But the bacteria found in Arctic permafrost aren’t just a threat for animals and those who depend upon them for subsistence. It’s also possible that miners and oil workers would come into contact with thawing soil containing unknown microbes, Jensen says. She once had a member of her team contract a “seal finger,” a bacterial infection of the hand that was acquired while digging up decades-old seal carcasses. She doesn’t think it’s a “huge risk” for most people, but “the possibility certainly exists,” she said.
“Things can be frozen for a very long time and then get out. And if somebody is in contact with them, at the right time, in the right way, it’s conceivable,” she said. An infection like seal finger, she pointed out, isn’t directly transmissible to other people, and it responds to standard antibiotics. Other bacterial infections might behave differently.
There is one relatively easy way to prevent outbreaks: vaccines. Although it is kept in highly secretive locations, a smallpox vaccine does exist, should the virus rise once more from Siberian soil. And ongoing research into the role Arctic microbes play could help protect the world from future pandemics. In 2005, researchers in Alaska were able to recover bits of 1918 flu virus from someone buried in the thawing permafrost. They sequenced the deadly flu and created a vaccine for it—an important contribution to preventing a similar epidemic from breaking out again.
As for bacteria like anthrax, “there’s a very good and very stable and relatively inexpensive vaccine” for animals, Blackburn said. “It is the number one means of reducing both livestock anthrax and human anthrax.” Since the 2016 outbreak, vaccinations of Russian reindeer resumed, with more than 600,000 reindeer vaccinated each year.
Another critical way to prevent the spread of disease, in the Arctic and elsewhere, is being able to diagnose and treat it quickly, Blackburn said, and to educate the community on what steps they can take to protect themselves and others. “For that 2016 outbreak, there was quite a large community that had no real firsthand experience with anthrax,” Blackburn said. “That can really change the dynamic, because now you’ve got to educate that population, you’ve got to determine what’s causing it, you’ve got to determine what kind of preventative measures might work to reduce the severity of the disease and getting vaccines distributed.”
Climate change isn’t just changing what we know about diseases in the north. In a warming world, many southern diseases are advancing northward—as the ranges for disease-bearing mosquitoes and ticks, for example, expand. In pandemics like the current coronavirus outbreak, diagnosing and treating an emerging or reemerging disease, as well as educating the community on how to prevent its spread, can go a long way. If there’s one thing we can learn from the virus currently ravaging communities around the globe, it’s that there are a number of steps we can take to prepare better for the next epidemic—from fighting the global warming that makes them more common to preparing and supporting our hospitals, labs, and communities before the next health disaster arises.