“The human-animal interface has become quite unstable”was alarmed a few days ago by Dr. Mike Ryan, Head of Emergencies at the World Health Organization (WHO).
“Disease emergence and amplification factors have increased,” according to him. He has just been seen with monkeypox, but not only that, he warned.
This one smallpox monkeypox – “monkeypox” in English- caused by a virus transmitted to humans by infected animals — most often rodents — is the latest example of the proliferation of these zoonoses.
These are infectious diseases that vertebrate animals can transmit to humans. Some even end up becoming specifically human, like the Covid-19.
According to the World Organization for Animal Health, about 60% of emerging diseases are of zoonotic origin. Appearing thousands of years ago, since humans intensified their interactions with animals by domesticating them, they have seen their frequency greatly increase over the last twenty or thirty years.
At issue, “the intensification of travel, which allows them to spread more quickly and uncontrollably”Marc Eloit, head of the Pathogen Discovery Laboratory at the Institut Pasteur, told AFP.
By occupying larger areas of the globe, humans are also helping to disrupt the ecosystem and promote the transmission of viruses.
The intensification of industrial livestock farming thus increases the risk of the spread of pathogens among animals. The wildlife trade also increases human exposure to the microbes they are likely to carry.
Deforestation, on the other hand, increases the risk of contact between wildlife, domestic animals and human populations.
“When we deforest, we reduce biodiversity; we lose animals that naturally regulate viruses, which allows them to spread more easily.”Benjamin Roche, a biologist at the Institute for Development Research (IRD), a specialist in zoonoses, told AFP.
Climate change will also cause many animals to flee their ecosystems to more livable areas, a study in Nature warned in late April.
However, by mixing more, the species will transmit their viruses more, which will encourage the emergence of new diseases that are potentially transmissible to humans.
“We need improved surveillance in both urban and wildlife, so we can identify when a pathogen has passed from one species to another.”said Gregory Albery, an environmental health specialist at Georgetown University in the United States and co-author of the study.
“And if the receiving host is urban or close to humans, we should be particularly concerned.”
The study paints a future “network” of viruses jumping from species to species, and growing as the planet warms. “We now have easy and fast means of investigation that allow us to react quickly in the event of the appearance of new viruses.”reassured Marc Eloit, from the Pasteur Institute.
“We are also able to develop vaccines very quickly”as seen with the Covid-19.
“A whole new line of disease is likely to emerge, potentially dangerous. We need to be prepared.”warned Eric Fèvre, Professor of Veterinary Infectious Diseases at the University of Liverpool (UK) and the International Livestock Research Institute (Kenya).
This means, according to him, “focus on public health of the population” in the most remote environments and “Better study the ecology of these natural areas to understand how different species interact“.
Since the early 2000s, the concept of “One Health” has been emphasized: it promotes a multidisciplinary and comprehensive approach to health issues with close links between human health, animal health and health. global ecological status.
France also launched the international “Prezode” initiative in 2021, which aims to prevent the risk of zoonotic emergencies and pandemics by strengthening cooperation with the most affected regions of the world.