Climate change can unleash dormant viruses
LONDON: Climate change is melting permafrost, or soils that have been frozen for years, releasing ancient, once-dormant viruses and bacteria that are springing back to life, the BBC reported.
Last August, in a remote part of the Siberian tundra, a boy, 12, died and at least 20 people were hospitalised after contracting anthrax, an infectious disease caused by bacteria.
Theory has it that more than 75 years ago, a reindeer with anthrax died and its frozen carcass became trapped beneath a layer of permafrost. It stayed there until a heatwave last year caused the permafrost to thaw.
Investigations into the anthrax outbreak sparked concern that smallpox could return.
Bacteria can stay alive in permafrost for long periods of time - possibly even a million years.
"Permafrost is a good preserver of microbes and viruses, because it is cold, there is no oxygen and it is dark," said evolutionary biologist Jean-Michel Claverie at Aix-Marseille University in France, BBC reported.
Scientists have discovered intact 1918 Spanish flu virus in corpses buried in mass graves in Alaska's tundra. Smallpox and the bubonic plague are likely buried in Siberia.
Prof Claverie said: "There is now a non-zero probability that pathogenic microbes could be revived, and infect us.
"... If the pathogen hasn't been in contact with humans for a long time, then our immune system would not be prepared."