According to some, the next pandemic may come not from bats or birds, but from ice melted by rising temperatures.
What would happen if we were suddenly exposed to deadly bacteria and viruses that have been “dormant” for thousands of years, or that we have never met before?
Subzero temperatures serve to preserve biological samples because the enzymes that break down tissues and the macromolecules that make up living matter are inhibited at subzero temperatures.
Living cells suffer from freezing and thawing processes because ice crystals break cell membranes and can greatly lose their viability. To avoid this damage, there are laboratory protocols.
Viruses, which are much smaller and simpler subcellular particles, are kept “hibernated” by freezing, with their biological activity inhibited, but viable as infectious particles if the temperature at which they are capable of developing the infectious process is recovered.
Global temperature increase and release of frozen pathogens in nature.
In 2016, an anthrax outbreak in northern Siberia that killed a child and infected at least seven other people was blamed on a heat wave that melted the permafrost and exposed the carcass of an infected reindeer. Prior to this, the last outbreak in the region had been in 1941.
Anthrax (or anthrax) is a serious infectious disease caused by a gram-positive, bacilliform bacterium known as Bacillus anthracis. Anthrax can be found naturally in the soil and commonly affects pets and wildlife throughout the world. Although not common, people can contract anthrax if they are in contact with infected animals or contaminated animal products.
Scientists have discovered fragments of RNA (ribonucleic acid) from the 1918 Spanish flu virus in corpses buried in mass graves on the Alaskan tundra. Smallpox and the bubonic plague are also probably buried in Siberia.
In the 1890s there was a major smallpox epidemic in Siberia and one city lost up to 40% of its population. The bodies were buried under the top layer of permafrost on the banks of the Kolyma River. 120 years later, floodwaters from the Kolyma have begun to erode the banks, and melting permafrost has accelerated this erosion process.
In recent developer work at Lake Hazen, soil and sediment samples were collected where meltwater flowed from local glaciers. The RNA and DNA from these samples were then sequenced to identify sequences that match those of known viruses, and their potential animal, plant, or fungal hosts. They also determined the probability that these viruses would infect different groups of organisms.
The results were published in the scientific journal Proceedings of the Royal Society B, and suggest that the risk of viruses and other microorganisms spreading to new hosts is greatest in nearby locations where large amounts of glacial meltwater flow.
They did not determine how many of the identified viruses were unknown, which they did, nor did they assess whether these viruses were capable of triggering an infection.
However, last year, researchers at Ohio State University in the US announced that they had found genetic material for 33 viruses, 28 of them new, in ice samples taken from the Tibetan Plateau in China. The viruses were estimated to be approximately 15,000 years old.
In 2014, scientists from France’s National Center for Scientific Research managed to revive a giant virus they isolated from the Siberian permafrost for the first time in 30,000 years.
Mollivirus sibericum is a giant virus discovered in 2015 by French researchers Chantal Abergel and Jean-Michel Claverie in a 30,000-year-old sample of Siberian permafrost, where the team had previously found the Pithovirus sibericum virus (which is not related to Mollivirus sibericum). the mollivirus). Mollivirus sibericum is a spherical virus with DNA 500–600 nanometers (0.5–0.6 μm) in diameter. Mollivirus sibericum is the fourth ancient virus to have been found frozen in permafrost since 2003.
Even so, it is important to point out that the probability of contagion is not the same as affirming that real infections or pandemics are going to occur. If viruses and intermediate species are not simultaneously present in the environment, the probability of dramatic events is low.
A study, published in the journal Geophysical Research Letters, found that permafrost thawing levels were 240% higher than historical levels and the ground sank 90 cm during the study, which lasted more than 12 years, between 2003 and 2016.
The researchers also recorded thawing at depths not expected until at least 2090, as predicted by the United Nations’ Intergovernmental Panel on Climate Change (IPCC).
On the other hand, the hypothesis is being considered that climate change will alter the range of presence in different ecosystems of some species, which could put new hosts in contact with old viruses or bacteria with which there was no prior contact and for those that there is no immunity.
Not just on ice.
Pathogens isolated from humans could also turn up elsewhere, not just in ice or permafrost.
In February 2017, NASA scientists announced that they had found microbes 10,000 to 50,000 years old inside crystals in a Mexican mine.
They were in the Cueva de los Cristales, part of a mine in Naica, in northern Mexico, which contains many milky-white crystals of the mineral selenite, formed over hundreds of thousands of years.
Older bacteria have been found in the Lechuguilla Cave in New Mexico, 1,000 feet underground. These microbes have not seen the surface for more than 4 million years.
Some researchers disagree. See link.
The cave never sees sunlight, and is so isolated that it takes about 10,000 years for surface water to reach the cave.
The microbiome is defined as a characteristic microbial community occupying a well-characterized habitat, with distinct physicochemical properties. This not only refers to the microorganisms involved but also encompasses their theater of activity.
Microbiomes need to be explored across our planet, not just in the Arctic, to assess potential risks.
It’s better to prevent than to cure.