"We are putting forward the French One Health research strategy"

From 5 to 7 April 2026, Lyon will host the ‘One Health Summit’, an international scientific and political summit. What does the ‘One Health’ concept entail?  

Eric Cardinale : This concept designates the recognition and interdependence of the links between animal health and human health within the same environment. In tangible terms, this means the Forum brings together doctors, veterinarians along with entomologists, sociologists and so on to look at health from a very broad perspective. This holistic and integrative approach enables the prevention and control of zoonotic diseases, the fight against antibiotic resistance, the consolidation of food security and the protection of biodiversity and ecosystems. For my part, I discovered this approach's added value when working on a long-term project on a group of islands in the south-west Indian Ocean. At that time, I was part of the Sega network (Epidemic Surveillance and Alert Management) set up in 2009 and financed by the Agence Française de Développement (AFD, French Development Agency). Initially this network was dedicated to the surveillance of human infectious diseases but, thanks to my initial training as a veterinarian, we managed to broaden its focus in 2013 to include zoonotic and animal diseases which human health authorities knew little about at the time. This integration of skills enabled the very early identification of a few cases of inter-species transmission of Rift Valley fever in a village in the Comoros. This is a viral haemorrhagic disease that's transmitted from ruminants to humans. This early identification and the collaboration between the human and animal health research spheres meant we were actually able to block the emergence of the epidemic in human populations.

In recent years, One Health has become an established term in international discussions and in UN vocabulary. How far back does it go?

E. C.: The concept of One Health dates back to the 18^th century when human and veterinary medicine were not separated even though the term didn't actually even exist then. Hyperspecialisation and the distinction between the two spheres arrived later – in the 19^th and 20^th centuries.

In the early 2000s One Health came back to the fore during the avian flu crisis in Southeast Asia. The Covid-19 pandemic highlighted the interdependence between human health, animal health and environmental health which led to this term becoming established at last. In 2021, the quadripartite represented by the World Health Organisation, the World Organisation for Animal Health, the Food and Agriculture Organisation and the United Nations Environment Programme set up the dedicated One Health High Level Expert Panel. This is particularly useful as currently zoonoses account for 60% of all infectious diseases and 75% of emerging infectious diseases.

Has France incorporated this concept into its health and scientific tools? 

E. C.: France has fully adopted this issue, as the international Prezode initiative shows. This was launched by President Macron in 2021 at the One Planet Summit on biodiversity and now has 170 partners, including 15 governments.

Since then, all scientific disciplines have taken up the idea in a continuum that ranges from life and health sciences to the human and social sciences and also including environmental sciences, mathematics and computer science. There are several areas of research – understanding interdependencies and interfaces like animal reservoirs; modelling for enhanced prevention; identifying social and economic determinants which is why participatory surveillance is so important to make innovative measures that result from research projects acceptable; developing tools and methods like the system for active surveillance of avian influenza; and – the most important – aiming for their operational implementation through collaborative research projects, training and providing advice for public policy-makers.

As for the French healthcare system, the One Health approach has been officially recognised since the 2023–2033 national health strategy. Key organisations like the ANSES, Santé Publique France and the French Health, Agriculture, Environment and Research Ministries have since created a task force to work on this theme. However, work remains to be done to break down silos because, so far, not many people have implemented the One Health approach in practice.

In this positive context for One Health, the programme agencies entrusted to CNRS, INRAE and Inserm management have launched a prospective study on the subject and you have been appointed coordinator. Where did this idea come from and what are the objectives?

E. C.: These three agencies – 'Climate, Biodiversity, Sustainable Societies' for the CNRS, 'Agriculture et Alimentation Durables, Forêts, et Ressources Naturelles Associées'  for the INRAE and the Agence de Programmes de Recherche en Santé'   for the INSERM – work at the interface of health, biodiversity and climate change. The One Health approach reconciled their respective research efforts so they found it important to collaborate so that duplications could be avoided and blind spots identified, with the ANSES overseeing the whole process.

In practice, we will be working in two main areas. The first involves data on different aspects of health which is an extremely sensitive subject. The fragmentation and heterogeneity of these data are obstacles to the early detection of emerging diseases because solid data are required to inform public policy making effectively. This means it's therefore necessary to access, share and standardise all data in compliance with the FAIR principles  if the One Health approach is going to work.

The second focus area is the French overseas territories which host five of the 34 biodiversity hotspots identified by the International Union for Conservation of Nature and Natural Resources. (IUCN). However, these territories are particularly vulnerable to climate change whether in terms of rising sea levels, an increase in extreme weather events or the spread of infectious vectors like the tiger mosquito on Réunion Island, half of whose population is now affected by chikungunya. These overseas economies also host specific agricultural and consumption systems that need to be studied from a One Health perspective. These include plantations like the banana monocultures in Martinique – that have long been treated with chlordecone – and traditional hunting practices like the hunting of a Madagascan hedgehog, the tangue, on Réunion Island.

This working group's objective is to put forward a French One Health research strategy. We'll be publishing our initial findings at the end of this year with the aim of releasing a strategy document in the next two to three years. We really don't want to just engage in another bout of One Health washing because the term has been so overused in recent years and instead aim to show we can rapidly become operational.