Keep in mind that the vast majority of viruses are unique to only one species. But with the amount of viruses circulating, this has left through all epochs high numbers that have become transmissible in another way by chance of mutation. And sometimes to us. The scientific name is zoonosis: an infectious disease that has passed from animals to humans. The COVID-19 pandemic is a zoonosis, although we are not yet sure of the animal of origin.
By changing its territory, an animal can therefore encounter an animal that it would never have encountered before. Does it increase the likelihood of cross-species transmission of disease? Yes, say researchers, who have created a mathematical model of 3,139 species of mammals and the 40,000 viruses known to date that they host, and their current and likely movements over the next 50 years. Their conclusion is that over the next 50 years we can foresee 4500 cases in which a virus or even several viruses could “jump” from one species to another. The article appeared in the magazine on April 28 Nature.
Multiple options, multiple risks
So far, the biologists who have dealt with this question have been more concerned with one virus after the other: will it survive this or that environmental change, does it have mutations that can enable it to “jump” to another species.
But only with the size of the problem – these 4500 possibilities – does an alarm signal arise for people. When the researchers examined where these problematic species would have migrated in 50 years, they found that the vast majority were areas where our cities are expanding. For example, note in the New York Times Pathology-ecologist Gregory Albery, co-author of the study, could transmit its virus to a raccoon that lives comfortably in urban areas from a small rodent that had previously had little contact with humans.
In fact, it has already started, as figures from the last century show that 60% of the new epidemics that have hit us are zoonoses. The likely result of unprecedented 20th-century contacts between humans and certain animal species, such as the bats of Southeast Asia.
Incidentally, the researchers note, there are concerns about the impact these new viruses will have on humans, but it’s important to remember that for an already weak animal population, a new virus that its immune system isn’t equipped to deal with can have a devastating impact .
Journalist Ed Yong uses the word “pandemic” – we have entered a “pandemic era” in which large numbers of new hosts are carrying old viruses and maybe even new ones. This situation was created by the collision of two human impacts on nature: climate change and loss of wildlife habitat. And this situation, Yong concludes, lies at the intersection of three of our existential fears: “climate change, pandemics, and the 6th mass extinction” of life on Earth. “These three fears are actually the same mega problem. “As we emerge from one pandemic, he warns, we might do well not to underestimate the importance of being better prepared for the next…