Night falls in the Mexican jungle of Yucatan, where the veterinarian Omar García extracts blood and fluids from a bat that will be analyzed to monitor zoonoses, diseases transmitted from animals to humans.
The last word has not yet been said on the origin of the covid-19but this Franco-Mexican project aims to detect viruses that can cross the wild species barrier and reach humans in tropical climates, which would help to counter new pandemics.
The winged mammal, in the sights of the world scientific community as a possible vector of the coronavirus, remains immobile, obedient, showing its sharp fangs as if smiling, before being released by García, a specialist in vector-borne diseases.
Scientists from different fields from the Institute for Research for Development (IRD) of France and the state National Autonomous University of Mexico (UNAM) have been collaborating since 2017 on this study that includes a modern laboratory, named Eldorado, in Mérida, the capital of the state of Yucatan (east).
The specific objective is to know how different viruses that circulate between animals, birds, rodents, excrement or mosquitoes can potentially end up in humans.explains Audrey Arnal, from the IRD.
“This is zoonosis (…), understanding what the consequences of human contact with wildlife could be and then understanding what could be the next epidemic that can come out of nature,” says the expert in infectious diseases to the AFP.
Scientists take samples of all kinds of animals from the rich ecosystem of this tropical rainforest, where they have identified 61 species of mosquitoes.
“We have many questions” to “try to complete the history of the transmission cycle” of the viruses, explains María José Tolsá, a biologist at UNAM, who after a decade of research finally feels that her effort is valued.
“Now the importance of our work is identified, that a pandemic has serious consequences for health, the economy. How much is a pandemic worth and how much is prevention?”, he reflects among cattle bellowing in a rural area of the municipality of Tzucacab .
The research could be carried out in any jungle area in the world, but Yucatan was chosen because rapid deforestation has made it “a highly emblematic region in terms of zoonoses emergency risks,” says Benjamin Roche, from the IRD and co-director of Eldorado.
Most of the transmissions occur in intertropical regions and it is estimated that between 500,000 and 800,000 viruses could affect humans, adds the French specialist in ecology and evolutionary biology.
The risks also increase with the expansion of the agricultural frontier and tourism, which multiply contacts between animals and humans, according to the researchers.
Thousands of trees have been felled in the Yucatan Peninsula to build the 1,554 km Mayan Train, which will start operating in December, but the government assures that it compensates for this loss with a forest planting program and the creation of the second reserve largest tropical rainforest in the world after the Amazon.
The key is to achieve a balance between the human being and nature, Arnal clarifies. “We cannot say ‘we are going to make a mountain out of the peninsula’ either. The population must live, eat, develop their economy.”
The research is carried out in 12 communities of the three states that make up the peninsula.
“In birds we have found species that have been identified as reservoirs for the West Nile virus or birds that are reservoirs for influenza,” explains Rosa Elena Sarmiento, from the virology laboratory of the UNAM Veterinary School.
Last December, almost two million farm birds affected by influenza were euthanized, viruses that researchers were unable to identify in the species they investigate.
Field work begins at dawn by placing a dozen fine nets similar to those used for volleyball in which birds are trapped, while at dusk bats and even owls fall.
Once in the traps, blood, fluid and ectoparasite samples (if they carry them) are taken; Scientists identify the animal, measure it, and record the data. Before releasing them, they verify that they are in good condition.
And then to the laboratory, where the material is analyzed.
“DNA is a great revealer (…), with the blood of the mosquito we can determine which species or which animal was eaten,” explains Arnal.
Blood samples will also be taken from the residents to determine if they carry any virus of animal origin.
The project also includes consultations with the communities to find out about their environmental and social problems, and encourage forms of coexistence with nature.
“We cannot get to impose (…), there has to be a dialogue of knowledge with the communities,” explains Erika Marcé Santos, a member of the Kalaankab NGO and liaison with the residents.
Eldorado is connected with laboratories in Africa, South Asia and other Latin American countries within the framework of the Prezode initiative (prevention of risks of zoonotic emergencies and pandemics), launched by France in 2022 and which brings together 22 countries and 200 organizations.
“What we are looking for in Yucatán is to devise a prevention strategy against zoonoses that can serve as an example to the whole world,” says Benjamin Roche.
Source: Ambito
