Thawing Permafrosts & Epidemics: The Case of Russia’s Anthrax Epidemic

by Carla Fetcas

In 2016, remote northern Russia experienced an outbreak of anthrax, a bacterial disease that, although very rare and not particularly contagious, can become deadly [1]. The reason for this outbreak in the Siberian Yamalo-Nenets region, during which several people were hospitalized, is believed to be the high temperatures in this region that year, going up to 35°C [1]. It is assumed that, due to the heat, the permafrost was thawing, which might have disclosed the carcass of an infected reindeer [1]. The big question researchers are concerned about is if it is possible and likely to reactivate pathogens like anthrax against the background of global warming [2].

This article will cover general information on anthrax, an analysis of other possible explanations for the mentioned outbreak and the issue of the climate crisis possibly causing similar health problems in the future by releasing ancient pathogens.

The anthrax disease is caused by the bacillus anthracis. The most prevalent symptoms of this disease range from fever, nausea and trouble breathing, to vomiting and shock, or multiple organ failure [3]. The bacterium produces toxins in the body, which disrupt blood vessel linings and lead to leakage of fluid (e.g., blood), and ultimately to shock or even death [4].

What makes it so treacherous is its ability to survive and lay low in soil for many years in the form of spores (reproductive cells produced by small organisms) [1]. In most cases, anthrax concerns livestock and wild game, which it usually enters through wounds. It can also be transmitted to humans, for instance, by eating contaminated meat or by inhaling anthrax spores [3]. The risk of infection is especially high for people like abattoir workers who work with dead animals [1]. There is a vaccine available against anthrax, but only for people in professions with a high risk of infection [3].

The interest for the B. anthracis pathogen was high in the 20th century in bioweapon development and was renewed in the context of bioterrorism during the 9/11 terror attacks in 2001, where letters with anthrax spores were sent out, killing and injuring people [4].

Media reports often regard the thawing of the permafrost as the only reason for the outbreak of anthrax in 2016. It complies with the narrative and the public’s idea of the climate crisis causing problems; in this case exposing dangerous pathogens. Nevertheless, this reasoning must be treated with caution, as the explanation is not that simple [4]. 

It is important to understand what the dynamics of permafrost are when connecting the unusually warm summer of 2016 with the outbreak of anthrax [4]. There is an active layer on top of the permafrost which freezes and unfreezes every year [4]. The permafrost’s upper layer passes through this process on a decadal or century time scale, whereas the actual permafrost remains frozen for thousands of years and more. Seasonal temperature changes, therefore, must be accompanied by very high temperatures and high heat conductivity in the soil to reach the “true” permafrost [4]. Thus, the permafrost changes only over long periods of time, because of climate shifts and not because of an acute weather occurrence, such as the 2016 heat [4]. Climatic changes are not expected to change the permafrost until around 2100 in the Yamal region. This means that the recent outbreak has not been (solely) caused by the high temperatures [4].

Examples of alternative theories explaining the outbreak on the Yamal Peninsula are found in the Russian government discontinuing the vaccination programme, which had been ongoing annually since 1930 and helped in eliminating anthrax, but was, at a certain point, stopped and only restarted in the case of further outbreaks [5]. Other possible explanations include reindeer overpopulation and blood-sucking insects being the actual transmitters of anthrax [4,5]. 

To sum up, it can be said that it is theoretically possible for ancient pathogens to be released from originally frozen solid in the distant future. This would be due to climate shift as a whole and not because of individual weather events, as in the 2016 Yamal case. A projection shows that this scenario will probably be limited to the anthrax bacterium, as its spores are very durable and viable, even over a long period of time. It must, however, also be said that, in most cases, the soil is too acidic for (even) the spores of the anthrax organism to survive in a very large number. It could, therefore, be stated that the release of pathogens from the permafrost are not of utter importance or alarmingly concerning [4].

Reference List:

[1] Russia anthrax outbreak affects dozens in north Siberia, BBC,, [Last accessed 30 April 2022].
[2] Michaeleen Doucleff, Anthrax Outbreak In Russia Thought To Be Result Of Thawing Permafrost, NPR,, [Last accessed 30 April 2022].
[3] Anthrax, Mayo Foundation for Medical Education and Research,, [Last accessed 30 April 2022].
[4] Karsten Hueffer et al., 2020, Factors Contributing to Anthrax Outbreaks in the Circumpolar North, EcoHealth 17,, [Last accessed 30 April 2022].
[5] Robert Gainer, 2016, Yamal and anthrax, Canadian Veterinary Journal Volume 57 (9),, [Last accessed 30 April 2022].
Categories Climate Science

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