One Health Approach

The One Health approach recognises that the health of people, animals and ecosystems is closely connected. It is an integrated approach that brings relevant sectors together to prevent and manage health threats at their shared interfaces. For zoonotic diseases, which are infections naturally transmissible between vertebrate animals and humans, it seeks to prevent transmission at its source rather than relying only on treatment after human cases appear.

Why zoonotic prevention requires One Health

A zoonotic outbreak cannot be understood through human healthcare alone. Its origins may involve infection in wildlife or livestock, human contact with infected animals, or environmental conditions that favour transmission.

• The human-animal-environment interface includes farms, wildlife habitats, markets and households where people and animals interact.
• Changes in land use, habitat disturbance and agricultural practices can alter contact between humans, livestock and wildlife, creating opportunities for spillover, when a pathogen crosses from an animal population into humans.
• Veterinary services, public health authorities and environmental agencies therefore need to share information and coordinate preventive action.

How the approach prevents outbreaks

One Health links early detection with action to reduce exposure. Surveillance findings must lead to practical interventions; collecting data alone does not prevent disease.

• Integrated surveillance connects information on human illness, animal infections and relevant environmental risks to identify emerging threats.
• Joint risk assessment combines expertise from different sectors to determine likely sources, transmission pathways and populations at risk.
• Prevention at the animal source can include vaccination where appropriate, veterinary care, farm biosecurity and safer animal-handling practices.
• Safe food handling, hygiene and protection for people working closely with animals reduce opportunities for infection.
• Coordinated outbreak investigation and laboratory testing help authorities identify the source and interrupt transmission promptly.
• Community participation and clear risk communication help preventive measures reflect local livelihoods and gain public cooperation.

National and international coordination

Effective implementation requires multisectoral coordination, with clear responsibilities, information-sharing arrangements and adequate capacity across human, animal and environmental health services.

• International cooperation matters because infected animals, animal products and people can move across borders.
• The Quadripartite brings together the World Health Organization, Food and Agriculture Organization, United Nations Environment Programme and World Organisation for Animal Health to support One Health cooperation.
• Its One Health Joint Plan of Action provides a shared framework for strengthening capacities and addressing threats at the human-animal-environment interface.
• One Health also addresses food safety and antimicrobial resistance, but its specific contribution to zoonotic prevention is linking source control with human-health protection.