Could the pandemics of the future hide in the ice of Siberia? Among the many health consequences of global warming there are also zombie viruses: pathogens that have remained hibernated in the permafrost for centuries and could be released into the environment, thus representing a terrifying, yet bizarre, new global threat.
Ancient, forgotten or unknown viruses
The news comes from researchers at the University of Aix-Marseille, the same ones who isolated a 48,500-year-old Pandoravirus from Siberian soil that was no longer frozen. As they report The Guardian And Science, analyzing the genomics of the samples revealed the presence of pathogen sequences “that have the potential to infect humans and start a new epidemic”. Ancient, forgotten or unknown viruses, which just like zombies could return from the oblivion of their ice prison, melted by abnormal temperatures.
What current research says
“We don’t know what viruses are out there in the permafrost, but I think there is a real risk that there could be one that could trigger an epidemic, like an ancient form of polio. We have to assume that something like that could happen.” , he has declared Marion Koopmans of the Erasmus Medical Center in Rotterdam. His team also collected 360 samples from Siberia and studies conducted to date have found several such bacteria Clostridium, including those that cause food poisoning, toxic shock and botulism. And many other finds are still being analyzed.
by Roberta Villa
In reality, a pathogen may have already emerged naturally from the frozen ground. In the unusually hot summer of 2016, the Bacillus anthracis which causes anthrax killed 2,649 reindeer in Siberia and sickened 36 people, resulting in the death of a 12-year-old. And although it might seem like the plot of an apocalyptic film, “we can expect anything, that’s why we shouldn’t underestimate the situation”, the professor tells Salute Marco De Andreavirologist of the Department of Public Health Sciences of the University of Turin.
Viruses found in permafrost
“The viruses isolated from the permafrost so far are decidedly different from those we study and know today, starting from their size. The first ones were found precisely because they are very large, visible with the optical microscope, and they are pathogens of amoebae: this This means that they may not be pathogens compatible with humans, even if some amoebae can spread from person to person through food or water.”
It is not surprising that these pathogens have survived for thousands of years in the ice. “Permafrost has the ideal characteristics for the cryopreservation of biological material – confirms the expert -. It is dark, the temperatures are very low and there are almost zero levels of oxygen. Freezing viruses and bacteria is an absolutely common practice in the laboratory: they we also keep them in liquid nitrogen at minus 140 and we know that it is enough to defrost them to reactivate them. Some lose their viral load, others become vital again exactly as before”.
As De Andrea recalls, “influenza viral RNA was found in the lungs of soldiers who remained frozen in the permafrost during the First World War, just as smallpox poxvirus DNA was found in an Italian Renaissance mummy.”
by Donatella Zorzetto
Should we worry?
The good news for us is that it takes a series of coincidences that make contagion from an ancient virus from the permafrost less likely, although not impossible. “Once thawed, survival is hours. A period of time in which the virus must be able to intercept a suitable living host and begin to reproduce. Water is usually not a good means of transport without a host, they are absolutely more animals, but also plants. And if it were not a human pathogen, it would have to be able to mutate a series of times before being able to undertake the leap from species to us.”
What’s scariest is what we don’t know yet. Or we don’t suspect. “The study conducted by the colleagues from Aix-Marseille is genomic, which means that they have not isolated a precise pathogen, only that there is compatible genetic material. We know that there are two large categories of viruses: the “naked” ones, such as for example the papilloma virus, are much more resistant than the coated ones, such as herpes, which has a lipid covering that degrades easily. But at the same time there is Covid, which is the most resistant coated coronavirus with which we have had to deal with. This tells us that we should expect everything, but above all that we should be better prepared to manage the thing, when and if it happens”, concludes De Andrea. This is why these discoveries should be “a warning to increase commitment to research, paving the way for broad-spectrum antivirals, a single effective drug against the most dangerous viruses. The Sars-Cov-2 pandemic and the probability that new strains of coronaviruses emerging in the immediate future have already highlighted the urgent need to identify new pan-coronavirus inhibitors.” And without broad-spectrum antivirals we will be powerless even against zombie viruses.