STEVE INSKEEP, HOST:
Russia is fighting a mysterious outbreak of disease. Dozens of people are hospitalized due to anthrax. Yes, anthrax, the bacterial infection so deadly that certain strains have been made into weapons. Now authorities do not know how this outbreak started in Siberia, but here's their hypothesis. They think that a heat wave thawed out anthrax that had been frozen in a reindeer carcass for decades. Here's NPR's Michaeleen Doucleff.
MICHAELEEN DOUCLEFF, BYLINE: The place where the outbreak is occurring is called the end of the earth, or the Yamal Peninsula. It lies high above the Arctic Circle at the top of the world. It's so cold there that the soil, called permafrost, is frozen solid more than 1,000 feet deep, or about the height of the Empire State Building.
Jean-Michel Claverie is a biologist at the National Center for Scientific Research in France. He studies pathogens in Russia's permafrost. I talked to him on Skype. He says the soil in the Yamal Peninsula is like a giant freezer, cold and dark.
JEAN-MICHEL CLAVERIE: Those are very good conditions for bacteria to remain alive for a very long time.
DOUCLEFF: In this case, the bacteria were anthrax. And more than 75 years ago, they killed a reindeer. The body got covered over in a thin layer of permafrost. For decades, it lay there frozen. Then this summer, a heat wave hit and a thick layer of permafrost melted. The theory goes that the reindeer's body rose to the surface. As it warmed up, so did the infectious anthrax.
CLAVERIE: Those infectious agents will come back to life and eventually infect people or herds of reindeer.
DOUCLEFF: Certain pathogens can lay dormant for decades in soil and come back to life. Russian officials say they're working hard to get the outbreak under control. They're vaccinating reindeer, burning the carcasses of dead animals. But Birgitta Evengard in Sweden says there's likely to be more cases of anthrax resurfacing. That's because climate change is causing the temperature in the Arctic Circle to rise very quickly.
BIRGITTA EVENGARD: It's about three times faster than in the rest of the world. And this means that the ice is melting, and the permafrost is thawing.
DOUCLEFF: A hundred years ago, there were repeated anthrax outbreaks in Siberia. More than a million reindeer died. Now there are about 7,000 burial grounds with infected carcasses scattered across northern Russia.
EVENGARD: It's not that easy to dig to bury these animals, so they are kind of very close to the surface.
DOUCLEFF: Wow. So there could be these outbreaks happening every summer?
EVENGARD: Yes, this is serious.
DOUCLEFF: Evengard is with Umea University and studies how climate change alters the spread of diseases. And she says it's not just anthrax that could be a problem. People and animals have been buried in permafrost for centuries. There could be bodies infected with all kinds of viruses and bacteria, frozen in time. She says scientists are just starting to look for it.
EVENGARD: So we really don't know. This is Pandora's box.
DOUCLEFF: There's the flu that caused the 1918 pandemic that killed more than 50 million people. There's also likely smallpox buried up there and the bubonic plague. So the question for researchers is, could these pathogens, like anthrax, ever be reactivated? Michaeleen Doucleff, NPR News.
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