Blog

Just four years ago the word of the year in the monumental Oxford English Dictionary was "post-truth" (posttruth), defined as "argumentation, characterized by a strong appeal to emotionality, which, based on widespread beliefs and not verified facts, it tends to be accepted as truthful, influencing public opinion ”. This means that while the scientific community promotes evidence-based behaviors and strategies, modern society may have arrived at a new model in which what matters is not truthfulness but attention and social signaling (McCarthy et al. , 2020). This often results in the dissemination of speculative, misleading or reinterpreted information as certain.

Today, while the SARS-Cov-2 emergency continues to devastate human health and national economies, the media are always on a frantic search for the most curious, disturbing and extraordinary news concerning this pandemic. In this crazy search, the available scientific information is reworked in a clumsy and misleading way only to excite and strike people's imaginations. For example: last summer medical research estimated that on average COVID-19 was lethal in about 1% of contagion cases, particularly affecting the most advanced age groups, while for the common flu there was a percentage of lethality of about 0.1%, ie 10 times lower. Well, a well-known online newspaper headlined: "The coronavirus is ten times more lethal than the flu". Without, however, adding essential complementary information, namely that, without the periodic flu vaccination, the severity of the flu would be comparable to that of the coronavirus! Obviously in these cases the aim is not to give the public a more understandable message, but to attract readers, get more contacts on the web and sell this visibility for advertising purposes. In practice, the interpretation of complex research conducted by a qualified and articulate scientific community ends up depending on the poor medical skills of a journalist.

What about the sudden notoriety enjoyed by many "experts" who too often, in the limelight, give their opinion on topics outside their specific competences. Hence even complex issues of ecology and zoology end up being "simplified" and so the fact that "bats are a natural reservoir of Coronavirus" quickly becomes "bats are responsible for COVID-19".

The ease and speed with which such lies are shared through social media accelerates this spread of disinformation and greatly amplifies its repercussions in the real world.

Would you ever entrust the care of a sick person to a landscaping architect? Or designing a bridge to an Origami specialist? So why not rely on the science of Biology to have a more reliable and broader view of this natural phenomenon called a pandemic and to understand how things really are on the planet where we live? This is what a naturalist's point of view is.

It is difficult to define viruses. They are not even cells, but something even simpler, because they consist only of a protein shell and nucleic acids. Very ancient microorganisms, in circulation for more than three billion years, therefore certainly well adapted and successful; we arrived just 250,000 years ago, just to understand. We know that they are unable to reproduce on their own, but they need the cells of a host. Darwinian theories of evolution, valid for the whole life on Earth, they also control viruses which, since their appearance, have gradually specialized to reproduce and survive better within other living forms, diversifying into an impressive number of different types. Each viral form ends up living in balance with its host who over time develops an adaptive immunity. This means that the host survives this sort of "parasitism" and the virus can thrive and spread.

The event that can upset this balance is the so-called spillover, the "leap of species". It occurs as a result of a rare random mutation that changes something in the virus and, if the mutation is favorable and if there are suitable conditions at that moment, such as proximity to another species, a new virus tries to expand into the new host. . Even when the new host species is man, in most cases the virus proves to be harmless, but sometimes causes more or less serious diseases, from simple colds to HIV. The human species is proving to be the ideal host for viruses, thanks to our presence all over the planet, our social habits, our ease of movement from one continent to another, which favor the spread of the infection. Sometimes the virus also has a particular adaptation that protects it from any excessive damage caused to the health of the host, ie it proves harmless to some "parasitic" subjects (our species calls them "asymptomatic") and therefore the virus not only it does not risk becoming extinct along with the host, but increases its chances of spread to other individuals.

It would therefore seem that we have no escape, but in reality there is a way to reduce the risk: just stop increasing in number and invading every natural habitat and every virgin territory, deforesting, polluting, hunting indiscriminately, causing climate change...

Ultimately, if we stop altering the natural balances and also modifying the behavior of other species, we will greatly decrease the opportunities to come into close contact with them and thus the occurrence of the so-called "species leap" will be even more unlikely. What happened in the Wuhan market is an extreme example of how NOT to behave: the coexistence, in a single place, of the most diverse wild animals, live or just slaughtered, in poor hygienic conditions, in direct contact with people and even consumed as food, has made this leap of species enormously more probable, with the effects we are all experiencing on our skin today.

As for this new pandemic, it is still not certain from which animal species the spillover towards man occurred; today the most probable candidate seems to be the Pangolin (Manis javanica). South China Agricultural University reported that our SARS-Cov-2 genome is 99% the same as that of a virus found in this small scaly anteater. It is still unclear how the transmission took place, but it likely occurred because the Pangolin is sold for food in the markets of China. In previous epidemics, the Mammals carriers of viruses with zoonotic potential, that is able to "jump" from animals to humans, were the Palm Owl (Sars), the Pig (A / H1N1) and the Camel (Mers).

The first investigations on animals, with the aim of researching the progenitor of SARS-Cov-2, had focused on Bats and had shown a genetic similarity between 85 and 96% with viruses that live in at least a couple of chinese bats, Rhinolophus sinicus and Rhinolophus affinis.

At this point, for the journalist, or for the expert on duty, who has already run out of patience and attention, and who must summarize, this information is sufficient. So in a moment it is concluded that the first origin of this pandemic are bats. Also thanks to the fact that, still for many people, the bat represents a dark and fearsome creature (actually fewer and fewer people in recent years), so what could be better than choosing it as a scapegoat for all our sins?

Also in this case, at least three essential information was not taken into account:
- The 96.2% similarity between the two viruses in question does not mean much (between us and the Gorillas the similarity is 98.6% and we are certainly not the same) and then, in fact, that virus found in Rhinolophus affinis does not it is compatible with humans and cannot infect it (our ACE2 membrane receptor is incompatible with the surface proteins of that virus);
- Bats are easy to catch and study all over the world and due to their characteristics, which we will discuss later, they can tolerate many different species of viruses, so any good and diligent virologist who wants to find something to study, and publish, yes primarily addresses this animal group. The result is that bats are the most studied from this point of view and the viruses that are known to them are obviously many, so much so that they are often referred to as "reservoir species". In fact, recent research, which has examined each order of mammals, indicates that the number of viruses that can infect humans in bats is similar to that present in other mammals (Mollentze and Streicker, 2020; Olival et al. , 2017);
- Bats (Order of Chiroptera) have over 1400 different species, spread all over the world, therefore accusing generically "the bat" means nothing and unnecessarily alarms people. Each species is different from the others (obviously) and even their viruses are not always the same. It would be like saying that the members of the Order of Carnivores, from Ermine to Lynx, from Dingo to Tiger, are all the same...

Unfortunately, the media try in every way to make the news, without realizing the damage that certain statements can cause. Alarming people about the alleged danger of bats can have very harmful effects. Even a few wrong actions, made out of fear and aimed at a bat colony, have the potential to cause irreparable damage to already vulnerable species. And by now, after years of patient and painstaking disclosure by zoologists, we should all be clear about the critical and multivariate contribution that bats make to human well-being (Kunz et al., 2011). Just think of the work that each bat does every night, silently and tirelessly hunting insects harmful to agriculture or health, without polluting and without asking for anything in return. They are also an important resource for scientific research, because understanding how they manage to be particularly resistant to viruses is very important in the medical field. Among other things, these mechanisms also seem to be responsible for their incredible longevity, which can even reach a record of forty years, against the two years of a common shrew that has the same size as them. We must therefore look at these animals with interest and avoid hasty and superficial conclusions that could arouse foolish fears and compromise their survival, putting even more the terrestrial ecosystems, already severely altered and plundered, into crisis.

In this Anthropocene we are witnessing a severe crisis in biodiversity, triggered by artificial human modifications to the climate, landscape, flora, fauna, composition and consumption of soils. Many species fail to adapt to what we ourselves cause and unfortunately the populations of many bat species are also in worrying decline due to disturbance or destruction of important shelters, the spread of pesticides, development of intensive agriculture, felling of trees old or decaying, wind farms badly located in the area and, more generally, due to the alteration, fragmentation or disappearance of the natural environments in which these mammals hunt and take refuge. So, let's not add more useless and silly threats by portraying these beautiful animals as if they were greasers. It is good to always keep in mind that in this pandemic of ours, the greaser par excellence is undoubtedly man. We are the ones who are spreading SARS-Cov-2 around the world. And we can also transmit the virus to animals we come in contact with. It already happened. One of the first infections involved a tiger from a zoo. Recent research examined 410 different species of birds, fish, amphibians, reptiles and mammals to assess which ones were potentially most vulnerable to SARS-CoV-2 based on the compatibility of their ACE2 cell membrane receptor with the virus. As was to be expected due to genetic proximity, several species of primates, such as the lowland gorilla, the Sumatran orangutan and the white-cheeked gibbon, were particularly at risk. Always at high risk are followed by marine mammals such as the Gray whale and the Bottlenose dolphin, at medium risk domestic animals such as cats, cattle and sheep, while at low risk are dogs, horses and pigs (Damas et al., 2020). A distant risk concerns the possibility that we humans can also transmit SARS-Cov-2 to our bat friends. Yes, you read that right, in fact it is the opposite of what people commonly think. In this case a rare spillover should occur, because the genetic distance between us and the bats is great, but we cannot rule it out. This is why EUROBATS (United Nation environment program) issued a notice last May in which it is recommended to take all precautionary measures to minimize any potential risk for wildlife, including bats. The same bat doctors who study them (in Italy we are about forty) must have special permits from the Ministry of the Environment and the Minister of Health to handle them and must have gloves and a mask (https://www.eurobats.org/node/2602).

If we want to get the best out of this singular and tiring 2020, we must all work hard to fight disinformation, always critically evaluating the information that bounces on the web, reflecting and verifying the sources. We always adopt a broad overview of phenomena, avoiding any reductive anthropocentric point of view. In particular, as speleologists, we must network, sharing passion and knowledge and always striving to safeguard the good name of bats because a large part of the life present in our caves depends on the survival of these extraordinary animals. And if, for reasons of social distancing and relief of medical staff (or for any other good reason), we inevitably have to reduce our speleological activity, let's behave responsibly and realize that, if we want to contain the deaths and pains that this virus is giving us, we must necessarily surrender a certain share of our freedom. There is no other solution.

Paolo Agnelli

Bibliographical references
Damas J., Hughes G.M., Keough K.C., Painter C.A., Persky N.S., Corbo M., Hiller M., Koepfli K., Pfenning A.R., Zhao H., Genereux D.P., Swofford R., Pollard K.S., Ryder O.A., Nweeia M.T., Lindblad-Toh K., Teeling E.C., Karlsson E.K., Lewin H.A., 2020. Broad host range of SARS-CoV-2 predicted by comparative and structural analysis of ACE2 in vertebrates. Proceedings of the National Academy of Sciences, 117 (36) 22311-22322; DOI: 10.1073/pnas.2010146117.
Kunz, T.H., de Torrez, E.B., Bauer, D., Lobova, T., Fleming, T.H., 2011. Ecosystem services provided by bats. Annals of the New York Academy of Sciences. 1223, 1–38.
Lewandowsky, S., Ecker, U.K., Seifert, C.M., Schwarz, N., Cook, J., 2012. Misinformation and its correction: Continued influence and successful debiasing. Psychological Science in the Public Interest, 13, 106-131.
McCarthy, I.P., Hannah, D., Pitt, L.F., McCarthy, J.M., 2020. Confronting indifference toward truth: Dealing with workplace bullshit. Business Horizons, 63, 253-263.
Mollentze, N., Streicker, D.G., 2020. Viral zoonotic risk is homogenous among taxonomic orders of mammalian and avian reservoir hosts. Proceedings of the National Academy of Sciences, 117, 9423-9430.
Olival, K.J., Hosseini, P.R., Zambrana-Torrelio, C., Ross, N., Bogich, T.L., Daszak, P. 2017. Host and viral traits predict zoonotic spillover from mammals. Nature, 546(7660), 646-650.

Questo sito o gli strumenti terzi da questo utilizzati si avvalgono di cookie necessari al funzionamento ed utili alle finalità illustrate nella cookie policy. Se vuoi saperne di più o negare il consenso a tutti o ad alcuni cookie, consulta la cookie policy. Cookie policy