Small colored sacks hang from the branches of a bush. There are about twenty cloth bags, the kind used to store children’s snacks at school. Inside them, instead of a sandwich and some cookies, there are bats. Some protest their confinement with timid sounds: a few minutes before they were resting peacefully in the darkness of a cave in La Noguera, in the province of Lleida. The ecoepidemiologist Jordi Serra-Cobo opens the bags and observes if they have defecated. Their droppings can help prevent a new epidemic.
Serra-Cobo is a professor at the University of Barcelona and a member of its Biodiversity Research Institute (IRBio). He was one of the first theorists, 30 years ago, of ecoepidemiology, the study of how and why a virus is transmitted at a certain time and place. There are already 50 research centers around the world that share data on ecoepidemiology online.
Serra-Cobo is one of the main experts in Spain in the transmission of zoonotic diseases by bats and other mammals, such as rodents or wild boars. Zoonotic infections are those that are transmitted from animals to humans. In the 21st century alone, there have already been five coronavirus epidemics, in addition to the Ebola virus. All, Serra-Cobo recalls, would have come from the largest reservoir of virus in an animal species, bats. The World Health Organization (WHO), in its report last March on the possible origin of covid-19, corroborated that “most emerging diseases originate in animal reservoirs, and there is solid evidence that most of the current human coronaviruses were originated in animals ”.
It is above all the predators that feed on bats, or domestic animals in contact with these flying mammals, Serra-Cobo summarizes, that serve as hosts for the virus and end up infecting a person. The hyperconnection of the globalized society does the rest, as happened from December 2019 with the covid-19, which allegedly spread throughout the planet from the Wuhan animal market, in China.
In the 21st century alone, there have already been five coronavirus epidemics, in addition to the Ebola virus. All are suspected to have come from bats
Bats are not in themselves a threat to humans, on the contrary: they are, together with birds, a fundamental actor in the control of insect populations. The problem, academics from all walks of life agree, is the growing interference of human civilization in the green lungs of the planet, especially in Southeast Asia, Latin America and Central Africa. This was warned by the resolution on covid-May 19, 2020, signed by the Member States of the WHO, in which they committed to “prevent the establishment of new zoonotic reservoirs, in addition to reducing the possible risks of emergence and transmission. of zoonotic diseases ”.
64 million years on Earth
Serra-Cobo has formed a working tandem with Marc López Roig since 1993. They have entered hundreds of caves in countries in Europe, America and Africa. The first stone of their collaboration was a scientific milestone: after 22 years studying a colony of bats in Mallorca, they confirmed that these animals generated enough antibodies to rabies to develop group immunity. There are several reasons why bats are an ideal virus reservoir, Serra-Cobo details: “It is a mammal that has been on Earth for 64 million years, that is, it has been living with viruses for a long time. Most are gregarious, form groups and facilitate transmission. They are present all over the planet and in multiple habitats. And finally, they live for many years, easily exceeding 15 years of life ”.
López Roig is a sensitive man who is excited to hear the song of some bee-eaters, but he is also the muscle of the team: he clears access to the cave for hours, which since the last time they were, in March, has remained hidden among brambles. “Bats only have one young per season, and we find young dead specimens because when leaving the cave, they remain stuck in the thorns of the brambles,” explains López Roig. He is the one who runs to capture the cave bat and horseshoe bat specimens that they will analyze with the net. His soft voice seems to reassure them even when he takes blood samples. When you let them go, it takes a few seconds for them to wake up.
The objective of his mission in this cave in La Noguera is to find samples of coronavirus from the alpha and beta families in the excrement, which can be transmitted to humans. These samples are used for the CoNVat project, a biosensor device for rapid detection of coronavirus infections led by Laura Lechuga, a researcher at the CSIC and the Catalan Institute of Nanoscience and Nanotechnology. The device will be able to detect infections, not just coronavirus, in a time that will be around 15 minutes and at an affordable price. The idea is that the biosensor is used in outpatient clinics, health centers and pharmacies. Lechuga confirms to EL PAÍS that Serra-Cobo was the first person who raised the need to develop these rapid detection systems for coronavirus: “His knowledge is essential, because he was already talking about the biosensor before the pandemic. He had been saying for years that coronaviruses would scare us ”.
Serra-Cobo has been studying coronaviruses for 11 years, aware of what could happen. It causes vertigo to read the studies in which he has participated in the last decade warning of what humanity was facing, including proposals for plans to detect epidemics in European cities that were discarded because no one saw it as realistic.
Serra-Cobo’s first admonitory articles even predate Contagion, the best-selling journalist David Quanmen, published in 2012. “I have asked the same two questions of renowned scientists, some of the top experts on Ebola, SARS, viruses from bats, AIDS and the evolution of viruses, “Quanmen wrote in his book, predicting covid-19:” Will there be a new disease transmittable and virulent enough to cause an AIDS-level pandemic, or the 1918 flu, in the near future, killing tens of millions of people? If so, what will it be like and when? Responses to the first question ranged from “may be” to “likely”. To the second, the answers focused on RNA viruses ”.
Serra-Cobo confirms that now the effort of so long is taking shape. López Roig will publish a work that will collect two decades of analysis of how climate change is modifying the dynamics and seasonality of bats. One important variation, he says, is that the hibernation period is being drastically shortened. Animals are active longer. López Roig concedes that this may lead to an increase in the risk of spreading viruses. He explains it while with one hand he holds a horseshoe bat and with the other he extracts a sample that they will send to the Pasteur Institute in Paris, with which they have collaborated for years. The main lesson to be drawn from the pandemic, say the two UB biologists, is that prevention is always better than cure.