Revenge of the deep-frozen viruses

It’s been the plot of many too many films and science fiction stories: the ‘thing’ from the frozen wastes returns to life! (See, for example, Sky Atlantic’s current drama Fortitude.) But recent discoveries have shown that the scenario is all too possible.

A team led by Jean-Michel Claverie and Chantal Abergel reported this month the discovery of an entirely new giant virus – now named Mollivirus sibericum – one of four giant prehistoric viruses that have been discovered since 2003 [1]. Mollivirus sibericum was found in the permafrost in northeastern Russia, and with a diameter of 0.6 microns it can be observed through a conventional light microscope. Giant viruses contain between 500 and 2000 genes in contrast to viruses like Influenza A that has just eight genes.

Study of these giant viruses may be important for understanding virus mechanisms and indeed the emergence of life itself. Furthermore, understanding how viruses have evolved to take advantage of host-cell genes for their own replication may have implications for therapeutic targets.

The scientists who are studying the giant virus from the permafrost also warned that the combination of climate change and industrial or mining activity in newly thawed areas might awaken dangerous pathogens. They note in their publication that although they didn’t detect any pox or herpes viruses, “we cannot rule out that distant viruses of ancient Siberian human (or animal) populations could re-emerge as arctic permafrost layers melt and/or are disrupted by industrial activities” [1]

This work also raises the darker question of whether pathogens are ever really beaten. Although giant viruses don’t pose a threat to humans there is already evidence that the re-emergence of frozen pathogens might be causing diseases in Alaska [2] and Russian Arctic regions [3].

If you would like to comment on any of the issues raised by this article, particularly from your own experience or insight, Healthcare-Arena would welcome your views.

References

1. Legendre M, Lartigue A, Bertaux L, Jeudy S, Bartoli J, Lescot M, et al. In-depth study of Mollivirus sibericum, a new 30,000-y-old giant virus infecting Acanthamoeba. PNAS. 2015 Sep 8;201510795.
2. Brubaker M, Berner J, Chavan R, Warren J. Climate change and health effects in Northwest Alaska. Glob Health Action. 2011;4.
3. Revich B, Tokarevich N, Parkinson AJ. Climate change and zoonotic infections in the Russian Arctic. Int J Circumpolar Health. 2012;71:18792.