< strong>MOSCOW, Oct 28, Nikolay Guryanov. New research confirms that prehistoric viruses and bacteria will increasingly enter our habitat due to melting glaciers. What ancient pathogens can awaken and how great is the danger for people – in the material.
Glaciers and permafrost are the giant refrigerators of the planet. Microorganisms are preserved there – with the possibility of revival. Because of global warming, the ice mummies of animals that died in prehistoric times are thawing, and with them the pathogens.
A pathogen can be dangerous when, as a result of mutations, it acquires the ability to infect another species. This was the case, for example, with the zoonotic SARS-CoV-2, which migrated to humans from bats.
Canadian scientists decided to assess the likelihood of interspecies transmission of ancient infections sleeping in ice.
Stephan Aris-Brosou and his colleagues from the University of Ottawa collected sediment samples from the bottom of the polar lake Hazen and soil from seasonally drying channels, through which melt water enters the reservoir from local glaciers. The RNA and DNA in these samples were then sequenced to identify signatures close to known viruses, as well as potential carriers – animals, plants or fungi. And they ran an algorithm to calculate the probability of infection of unrelated organisms.
Study published in Proceedings of the Royal Society B, showed that the risk of virus spread increased as the amount of glacial meltwater increased.
Interestingly, increased flows from glaciers reduced the chances of dangerous genetic combinations in soil samples. Scientists explain this by the fact that water washes away the top layer of the earth along with the microorganisms found there.
But in Lake Hazen, the so-called fragmentation of the environment occurs, which limits the movement of genetic material and contributes to the drift of genes – the accumulation of changes. This favors the cross-species transmission of diseases by, for example, mosquitoes.
Climate change has triggered two processes. On the one hand, the amount of sewage has increased, and hence the ancient pathogens they carry. On the other hand, the habitat of animals capable of becoming distributors of revived diseases is shifting to the north. The thawed virus will sooner or later meet with a suitable quadrupedal or bipedal reservoir. “This can have dramatic consequences,” the authors of the work emphasize.
“Recipe for disaster”
In Russia, several scientific teams work with relic flora and fauna. They managed to wake rotifers, worms from eternal hibernation, grow a herbaceous plant from seeds 32 thousand years old.
In 1972, after thawing, a relatively large animal, the Siberian salamander (a species of newt about ten centimeters long), was brought back to life. He was observed for six months, after which he was killed for radiocarbon analysis. It turned out that the newt spent from 75 to 105 years in suspended animation.
In 2021, researchers from Ohio State University in the United States announced that they had found the genetic material of 33 viruses in ice samples from the Tibetan Plateau, 28 of which are unknown. Age – 15,000 years.
Some pathogens extracted from permafrost are not like anything at all. In 2014, Russian and French scientists saw a giant virus in samples from Siberia30 thousand years old. It could be seen even with an ordinary optical microscope. In vitro, it has infected a modern amoeba. width=”600″ data-crop-height=”337″ data-source-sid=”not_rian_photo” title=”Giant 30,000-year-old virus found in Siberian permafrost” class=”lazyload” width=”1920 “height=”1080″ decoding=”async” />
One of the authors of that study, Jean-Michel Claverie, said that the resurgence of infectious agents from permafrost looks like a “recipe for disaster.” His Russian colleagues were more restrained.
“If you think sensibly, the risk is minimal. The permafrost thaws every summer, and all its contents end up in nature. And people did not live in those places where they found giant viruses, therefore, it is unlikely that there are microbes that are dangerous for us,” saidresearch participant Lyubov Shmakova from the Soil Cryology Laboratory of the Institute of Physical, Chemical and Biological Problems of Soil Science, Russian Academy of Sciences.
However, modern medicines may be powerless against thawed diseases. A few years ago, scientists isolated and cultivated two bacterial strains from the Mammoth Mountain in Yakutia dating back to the middle Miocene (more than 14 million years ago). The analysis showed several genes associated with resistance to different groups of antibiotics.
An ancient evil has awakened
Anthrax spores have been preserved in the frozen remains of humans and animals for hundreds of years. At the same time, pestilence fields, as a rule, are close to the surface – it is difficult to dig deep holes in permafrost conditions. As the upper layer of the cryosphere thaws, the ancient bacterium has more and more chances to revive.
In the summer of 2016, there was an abnormal heat in Yamal — up to 35 degrees. The cattle burial ground thawed out, next to which deer were grazed. As a result, anthrax was diagnosed in 20 hospitalized reindeer herders. A 12-year-old boy who came into contact with an infected animal died. Fortunately, the outbreak was quickly contained. -width=”600″ data-crop-height=”402″ data-source-sid=”cc_0″ title=”Anthrax Bacilli Micrograph” class=”lazyload” width=”1920″ height=”1288″ decoding=” async” />
“Back then, all supervisory authorities worked quickly and very well,” says Boris Revich from the Institute of Economic Forecasting of the Russian Academy of Sciences. But we need prevention. We can't seem to explain to the funding officials that it's better than treating people later.”
The outbreak came amid a decline in reindeer vaccinations. In addition, insufficient control over the state of cattle burial grounds was revealed. In a recent workRevici and his colleagues pointed out the most dangerous pestilence fields. And reindeer grazing in potential areas of infection continues.
Indigenous peoples of the North are most vulnerable to prehistoric epidemiological threats. In 2020, scientists urged WHO to intensify paleomicrobiological research to protect the traditional communities of the macroregion.
“Very expensive theme”
Russia will suffer the most from the melting of permafrost, including a possible viral load. Frozen soils make up two-thirds of the country. In addition, nowhere else in the world is there such a large-scale economic activity in this zone. The melting cryosphere damages infrastructure – in particular, water pipes. Once there, harmful microorganisms can infect people.
“This is a very big and very expensive topic. Of course, I am not calling for the creation of a permafrost ministry. But we need an interdisciplinary comprehensive program. First of all, this is microbiological and bacteriological control, including the state of burial grounds. But other aspects should also be taken into account, for example, building codes should be revised,” notes Revici.
Russia is getting ready to face the “ancient evil”. Thus, the Scientific Center for Virology and Biotechnology “Vector” and the North-Eastern Federal University (Yakutsk) are experimenting with representatives of the mammoth fauna – they are looking for paleoviruses in fossil animals in order to find a way to deal with them.
At the base hydrometeorological stations of Roshydromet create a national permafrost background monitoring system with 140 observation points. Scientists are expected to receive the first data as early as next year.