Outbreak in Siberia

Last July, a mysterious illness began sweeping across the Yamal Peninsula—a cold, remote region of northwestern Siberia, a part of Russia. Animals and people began exhibiting strange symptoms. Within a few weeks, the disease had wiped out more than 2,000 reindeer. Hundreds of people were suspected of being infected and had to be hospitalized. After several days of being treated, a 12-year-old boy who had experienced fever and vomiting died. 

The strange infection was anthrax—a deadly disease that can cause sores on the skin, stomach problems, and pneumonia, an inflammation of the lungs. Sickness from anthrax hadn’t been reported in the region since 1941. So what caused it to suddenly reappear? Russian authorities are blaming an unusual heat wave that hit the region last summer. 

Last July, a mysterious illness began sweeping across the Yamal Peninsula. This cold, remote region lies in northwestern Siberia, a part of Russia. Animals and people began showing strange symptoms. Within a few weeks, the disease had wiped out more than 2,000 reindeer. Hospitals cared for hundreds of people thought to be infected. One of them was a 12-year-old boy who had suffered from fever and vomiting. After several days of treatment, he died.

The strange infection was anthrax. This deadly disease can cause skin sores, stomach problems, and pneumonia, an inflammation of the lungs. Sickness from anthrax hadn’t been reported in the area since 1941. So what caused it to suddenly reappear? Russian authorities think they know. They’re blaming an unusual heat wave that hit the region last summer.

Officials believe that warmer-than-average temperatures likely thawed the carcass of a long-frozen reindeer somewhere in the region. It had been infected with Bacillus anthracis (buh-SIL-us an-THRAY-sihs)—the type of bacteria that causes anthrax—more than half a century earlier. B. anthracis can form spores that are able to survive extreme conditions for long periods of time. Any animal or person who came in contact with the spores could have become infected with anthrax. The incident could be a troubling and unusual side effect of the climate change that is affecting many parts of the globe. 

Officials believe above-average temperatures triggered the problem. The warmer weather may have thawed the body of a reindeer somewhere in the region. The reindeer had been frozen for a long time. More than half a century earlier, it had been infected with Bacillus anthracis (buh-SIL-us an-THRAY-sihs). That’s the type of bacteria that causes anthrax. B. anthracis can form spores that survive extreme conditions for long periods of time. Any animal or person who came in contact with the spores could become infected with anthrax. Climate change is affecting many parts of the globe. The anthrax outbreak could be one of its troubling and unusual side effects. 

The Yamal Peninsula is located about 2,100 kilometers (1,300 miles) north of Moscow, Russia’s capital, and extends north of the Arctic Circle. The area is in a cold, flat, and mostly treeless region known as tundra. Tundra is covered by a layer of frozen soil (see Frozen Ground). In some places, this permafrost extends more than 300 meters (1,000 feet) beneath the surface. That’s about as deep as the Empire State Building is tall. Reindeer are common, and nomadic herders follow the animals from place to place as they graze across the Yamal Peninsula.

In winter, temperatures in Siberia can dip to -45°C (-49°F). Summers are cold too, with temperatures reaching only about 10°C (50°F). During July’s extreme heat wave, air temperatures hovered around 35°C (95°F) in some regions—much warmer than normal. 

The Yamal Peninsula is located about 2,100 kilometers (1,300 miles) north of Moscow, Russia’s capital. It reaches north of the Arctic Circle. The area is in a cold, flat, and mostly treeless region known as tundra. Tundra is covered by a layer of frozen soil (see Frozen Ground). In some places, this permafrost extends more than 300 meters (1,000 feet) beneath the surface. That’s about as deep as the Empire State Building is tall. Reindeer are common here. Nomadic herders follow the animals from place to place as they graze across the Yamal Peninsula.

In winter, temperatures in Siberia can dip to -45°C (-49°F). Summers are cold too. Then, temperatures reach only about 10°C (50°F). During July’s heat wave, the air was much warmer than normal—35°C (95°F) in some regions.

Scientists believe the abnormal weather is the result of an average increase in the temperature of Earth’s atmosphere. “For the last 30 years, the general trend has been warming,” says Vladimir E. Romanovsky, a geophysicist at the University of Alaska in Fairbanks. “The ground temperature in that region in particular increased by more than 1.5°C (3°F).”

During the summer, only the top layer of soil in the tundra—called the active layer—thaws. Typically, the summer thaw can reach anywhere from 40 to 60 centimeters (16 to 24 inches) below the surface. Because of the higher-than-usual temperatures, scientists think that last summer’s thaw extended much deeper. In fact, it’s estimated that in some parts of Siberia, the thaw depth increased by 50 percent. 

Scientists believe the abnormal weather is no fluke. It’s the result of an average increase in the temperature of Earth’s atmosphere. “For the last 30 years, the general trend has been warming,” says Vladimir E. Romanovsky. He’s a geophysicist at the University of Alaska in Fairbanks. “The ground temperature in that region in particular increased by more than 1.5°C (3°F).”

During the summer, only the top layer of soil in the tundra thaws. This is called the active layer. Usually, the summer thaw can reach anywhere from 40 to 60 centimeters (16 to 24 inches) deep. But the higher-than-usual temperatures may have changed that. Scientists think that last summer’s thaw extended much deeper. It’s thought that in some parts of Siberia, the thaw depth increased by 50 percent. 

No one is sure whether a thawed reindeer carcass was really behind the recent anthrax outbreak. Right now, that is the leading theory. But if permafrost—some layers of which are tens of thousands of years old—continues to thaw, outbreaks sparked by ancient bacteria and viruses could occur. In the early 20th century, northern Russia experienced many outbreaks of anthrax, leaving more than a million reindeer dead. Thousands of burial sites contain their infected carcasses. If the weather continues to warm, these now-frozen bodies could thaw, releasing even more anthrax spores.

And anthrax might not be the only disease to worry about (see Back From the Grave). Researchers have detected the 1918 Spanish flu virus in mass graves uncovered in Alaska’s tundra. People who died from diseases like bubonic plague and smallpox are also likely buried in Siberia. Some of these illnesses are no longer around to infect people. “There may be ancient organisms that don’t even exist anymore now, but because of this [thawing] will come back to life,” says Romanovsky.

No one is sure if a thawed reindeer carcass really caused the recent anthrax outbreak. Right now, that’s the leading idea. But some layers of permafrost are tens of thousands of years old. If permafrost continues to thaw, ancient bacteria and viruses could be exposed. They could spark new outbreaks. In the early 20th century, many outbreaks of anthrax happened in Russia. They left more than a million reindeer dead. Thousands of burial sites contain these infected carcasses. These bodies are frozen now. But if the weather continues to warm, they could thaw, releasing even more anthrax spores.

And anthrax might not be the only disease to worry about (see Back From the Grave). Researchers have found the 1918 Spanish flu virus in mass graves uncovered in Alaska’s tundra. People who died from diseases like bubonic plague and smallpox are also likely buried in Siberia. Some of these illnesses are no longer around to infect people. “There may be ancient organisms that don’t even exist anymore now, but because of this [thawing] will come back to life,” says Romanovsky.