An outbreak of anthrax that has killed more than 2,000 reindeer and sickened 13 people in Siberia has been linked to 75-year-old anthrax spores released by melting permafrost. It's an event of the sort many scientists have warned about: Warming temperatures reviving dormant diseases, perhaps even pathogens long-thought extinct. There are, however, ways to protect both livestock and humans from an anthrax infection, and the current outbreak is likely to end quickly, said George Stewart, a medical bacteriologist at the University of Missouri College of Veterinary Medicine. "This particular outbreak is going to fizzle out very quickly now that public health officials are in place," Stewart told Live Science. Zombie diseases The anthrax currently infecting reindeer and people in western Siberia likely came from the carcass of a reindeer that died in an anthrax outbreak 75 years ago and has been frozen ever since — until an unusually warm summer thawed permafrost across the region this year