Lyon: "One health" is on the agenda at the summit of states

This Tuesday, April 7th, Lyon takes on the air of a global health capital. Heads of state and government, international organizations, parliamentarians, scientists, economic players… all these stakeholders are gathering for the “One Health Summit,” with a simple idea to emphasize, almost too simple to be comfortable: human health can no longer be treated in isolation. The “One Health” approach aims to put the environment back into the equation, and not just as a footnote.

Born in the early 2000s and subsequently adopted by UN institutions, the doctrine has gradually taken shape around a shared definition: harm to humans, domestic and wild animals, plants, and ecosystems can reinforce each other and trigger chain reactions. Today, the initiative is led by a "quadripartite" group comprising the WHO, FAO, World Organisation for Animal Health, and the United Nations Environment Programme. This significant partnership signals that the issue is no longer just a slogan for conferences but a guiding principle that some would like to see incorporated into public policy.

"One health", three fronts to fight

The first warning, which keeps recurring, is zoonoses. The argument is familiar, but it gains weight with each successive crisis. The World Organisation for Animal Health reminds us that 60% of pathogens responsible for human diseases originate from domestic or wild animals. The origin of Covid-19 remains debated, and it is precisely here that the One Health approach aims to establish itself, at the interface between wildlife, livestock, and human populations, where surveillance is costly, sometimes inconvenient, and where inaction ultimately comes at a much higher price.

Another issue, less spectacular but undeniably real, is antibiotic resistance. Antibiotics save lives, but their use in both human health and livestock farming accelerates bacterial adaptation, and subsequently the spread of resistance between human and animal microbiomes, potentially via the environment. Researchers at INRAE ​​point out that widespread use in animal production promotes these mechanisms, and that a sound strategy requires ceasing to treat separately what constantly reinforces each other. This shifts the focus: the emphasis is no longer simply on treating, but on preventing harm.

The third pillar remains, often relegated to the background: pollution. Heavy metals, pesticides, endocrine disruptors, PFAS… the list is anything but abstract when the WHO estimates that approximately 20% of deaths from disease worldwide are linked to environmental disturbances. François Criscuolo, research director at the CNRS, calls for a “change in the way we approach health” by reintegrating the environment into risk analysis: a calm, almost bureaucratic statement, but one that signifies a break with the past. After Lyon, the question will be less about whether the concept is appealing than about who is willing to pay the political price, the price of compromises and concessions.