It is still impossible to estimate how long such microbes might remain infectious once exposed to outdoor conditions, the study authors admitted.
A team of scientists from France, Russia and Germany managed to revive seven viruses that remained in the Siberian permafrost, one of which it is 48,500 years oldand warned that climate change, due to the increase in temperature, could cause the release of those microbes against which humans have no immunity.
During the study, which was published on November 10 on the bioRxiv preprint server and has yet to be verified by other academics, they first sampled the permafrost in Siberia near the mouth of the lena river (Russia), as well as on the peninsula of Kamchatka. After analyzing the samples, the scientists were able to to preliminarily characterize 13 viruses and revive seven of them that were then cultured for viral genome sequencing.
As a result, they established that most (4) of the viruses belong to the giant genus ‘Pandoravirus’ and had not been discovered until now, while another three are from the ‘Mimiviridae’ and ‘Pithoviridae’ families. all of them infect amoebas and are the largest of these pathogens.
How long can they remain infectious?
In their work, the research team warned that if such microorganisms, which were “trapped in the permafrost for up to 2 million years” in a state of cryptobiosis, are released, a potential “public health problem” would appear.
“The situation could be much more disastrous in the case of plant, animal or human diseases caused by the reactivation of an unknown ancient virus”, they emphasized.
In this line, they emphasized that the recent and current pandemics have shown that “every new virus, even related to known families, almost always requires the development of very specific medical responsessuch as new antivirals or vaccines”.
They also admitted that they still it is impossible to estimate How long could such microbes remain infectious once exposed to outdoor conditions and how likely are they to find and infect “a suitable host“in an average time.
However, the risk of such a scenario “is bound to increase“, in the face of global warming with the thawing of the permafrost, the increase in the population in the Arctic as a result of its industrialization.