Thawing reindeer carcasses trapped in ice unleash anthrax in Siberia

Russia has seen its first deadly anthrax outbreak since the 1940s after infected reindeer encased in the permafrost thawed out in a heatwave, unleashing the disease.

A 12-year-old boy has died and 20 others are confirmed infected with anthrax in the remote region of Yamalo-Nenetsky, 2000km north of Moscow.

The outbreak came amid an unusual heatwave which pushed temperatures above 35C, killing over 2300 reindeer and causing wildfires.

The severe weather also melted the upper layers of permafrost, or permanently frozen soil, causing the disease to spring back to life after being virtually eradicated since a vaccine was licensed in 1970.

Russian authorities say the disease may have infected livestock after a reindeer corpse encased in the icy Siberian tundra for over 75 years thawed out.

“The anthrax spores lay in wait in the permafrost for more than a century,” Russia’s agriculture watchdog told AFP.

Anthrax is spread through a bacterium encased in a tough, rod-shaped shell.

The disease is typically ingested by grazing livestock and spreads to humans who handle or eat the meat of infected animals.

The local governor's spokeswoman Natalya Khlopunova said those infected included a family that "ate reindeer meat raw and drank the blood," saying "the nomads do have this custom."

The anthrax germ - Bacillus anthracis - sickens and causes death by proliferating in the bloodstream, where it releases powerful toxins.

Infection is usually treated by a long course of antibiotics but the treatment needs to start soon after infection.

Russian Health Minister Veronika Sknortzova flew out to the affected region to visit the hospital and quarantine zone, where up to 90 more people are under observation.

"We decided to do checks on all the reindeer herders' children, even if they show no signs of illness," Ms Khlopunova said.

Two-hundred troops specialising in containing infectious outbreaks have been sent to the region to decontaminate the area with helicopters and drones.

More than 160 nomadic herders have been evacuated from the contamination zone to a campsite 60km from the infection hotspot, as hundreds of dead reindeer carcasses are burnt.

The emergencies ministry flew out rescuers and essential supplies including stakes and reindeer hides for the evacuees to rebuild their traditional tents.

Health authorities are appealing for calm, rejecting claims of an “epidemic” as they administer the vaccine.

Matthew Henry is nine.com.au Network Editor. Follow @matthewhenry8