The Global Centre for Risk and Innovation (GCRI)
Many emerging infectious diseases in people originate in animals, and the health of people, animals, plants and ecosystems is linked through shared pathogens, shared environments, food and antimicrobial use. One Health treats these as one system governed by several sectors. This page sets out how risk moves across the human, animal and environmental interfaces, how it is observed, and what joint evidence serves for the ministries and services that share responsibility for it.
GCRI · Established · service level R0
One Health is an integrated approach that balances and optimises the health of people, animals, plants and ecosystems, because they share pathogens, environments, food and antimicrobials. Many emerging infections in people originate in animals, and resistance moves between sectors, so ministries of health, agriculture and environment need joint evidence.
How far each division sits from a large city, with the roads and airports that carry patients and supplies, shown for the Sahel as an example geography for this subject.
Human, animal and ecosystem interdependence. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.
Pathogens pass from wildlife or livestock to people where contact is frequent: land conversion, wildlife trade, intensive farming near forest edges and live animal markets. Each spillover is rare; the conditions that multiply contact are not.
Livestock and peri-domestic animals can amplify a pathogen before it reaches people, as with avian influenza in poultry or Rift Valley fever in ruminants after heavy rains. Animal outbreaks often precede human cases, which gives them warning value.
Antimicrobial use in people, animals and crops selects resistant bacteria and resistance genes, which circulate through food, water, wastewater and soils. Resistance found in one sector cannot be explained or controlled within that sector alone.
Temperature, rainfall, land use and biodiversity loss change the range and abundance of vectors and reservoir hosts. A changing climate shifts where diseases such as dengue, malaria and tick-borne infections can establish and persist.
Each term as this page uses it. Where a standard-setting body defines the term, the wording follows that body.
| Term | Definition |
|---|---|
| Zoonosis | An infectious disease transmitted between animals and people. |
| Spillover | The transmission of a pathogen from an animal host population to people or to another species. |
| Antimicrobial resistance | The ability of bacteria, viruses, fungi and parasites to survive medicines that once killed or stopped them. |
| Quadripartite | FAO, UNEP, WHO and WOAH acting together on One Health under a joint plan of action. |
Each indicator carries its unit, its cadence, the kind of source behind it and the evidence label a value would carry. No values are shown: a programme supplies them under its own authority.
| Indicator | Unit | Cadence | Source type | Label |
|---|---|---|---|---|
| Notified animal disease events | events per reporting period | immediate and six-monthly | National veterinary services reporting to WOAH | OFFICIAL |
| Human cases of priority zoonoses | notified cases | weekly | Notifiable disease surveillance | REPORTED |
| Antimicrobial use in animals | milligrams of active ingredient per kilogram of animal biomass | annual | National reports to WOAH ANIMUSE | OFFICIAL |
| Antimicrobial resistance in priority bacteria | percent of tested isolates resistant | annual | Laboratory surveillance reported to WHO GLASS | OBSERVED |
| Vector suitability | dimensionless index | monthly | Climate-driven ecological niche models | MODELLED |
| Forest loss at the human-animal interface | square kilometres | annual | Satellite land-cover change | OBSERVED |
| Joint multisectoral investigations | count of investigations conducted jointly | annual | One Health coordination mechanism records | REPORTED |
The topic as a computational graph: named sources feed the methods, an evidence review gates the outputs, and the decisions stay with the authorities that hold them.
Fig. 02Nodes carry their type, two metric rows and a state; connectors show what feeds what; dashed frames name the owners; the timeline is the cadence. Design of the pipeline, not a record of a run.
Named public datasets and institutional records, each with its licence class. Sources by agreement are used only under their terms and never republished.
| Source | What it gives | Licence class |
|---|---|---|
| WOAH World Animal Health Information System (WAHIS) | Official notifications of animal disease events and six-monthly status reports | Public, WOAH terms of use |
| FAO EMPRES Global Animal Disease Information System (EMPRES-i) | Animal disease events, zoonoses included, compiled from official and other sources | Public, FAO terms of use |
| WHO Global Antimicrobial Resistance and Use Surveillance System (GLASS) | National resistance and use data in human health | Open, attribution, WHO terms of use |
| WOAH ANIMUSE | Antimicrobial use in animals reported by national authorities | Public summaries, WOAH terms of use |
| Global Biodiversity Information Facility (GBIF) | Occurrence records for reservoir hosts and vectors | Open, licence per record (CC0, CC BY or CC BY-NC) |
| Hansen Global Forest Change | Annual forest loss and gain mapped from Landsat | Free and open, attribution (CC BY 4.0) |
| INSDC sequence archives (GenBank, ENA, DDBJ) | Pathogen genomes from human, animal and environmental samples | Free and unrestricted access |
Health Nexus prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.
| Who decides | The question | Evidence this page serves |
|---|---|---|
| National One Health coordination mechanisms | Which zoonoses to prioritise, and how ministries share surveillance and response | Joint risk assessments with each sector's evidence labelled; prioritisation inputs |
| Chief veterinary officers and veterinary services | When an animal outbreak warrants control measures with human health implications | Animal event reports beside human surveillance and sequence relatedness |
| Ministries of health and agriculture | Where to restrict or steward antimicrobial use across human and animal sectors | Resistance and use data compared across sectors, with comparability stated |
| Environment and wildlife authorities | Which land-use and wildlife trade practices raise spillover risk | Interface maps and host occurrence evidence, with sampling gaps shown |
The central questions concern spillover, resistance and coordination.
Many emerging infectious diseases in people originate in animals. Spillover depends on contact between species, which is shaped by habitat loss, agricultural expansion, livestock density and the handling and trade of animals. Once a pathogen reaches people, its spread depends on transmissibility, population mobility and the response.
Antimicrobial resistance follows a different but connected mechanism: every use of an antimicrobial selects for resistant organisms, and resistance genes move between bacteria and between humans, animals and the environment through water, soil, food and waste. The result is a slow-moving threat to the effectiveness of routine medicine.
| Method or data | What it shows | Limits |
|---|---|---|
| Integrated surveillance across human, animal and environmental sectors | Earlier and broader detection of shared threats | Sectors use different systems, definitions and reporting incentives |
| Wastewater and environmental sampling | Community-level signals of pathogens and resistance | Signals need careful interpretation and do not identify cases |
| Genomic sequencing | Pathogen origins, relatedness and resistance genes | Sampling is uneven across regions and species |
| Ecological and land-use modelling | Where conditions favour spillover | Identifies risk, not events; validation is difficult |
The current service level is R0: information and enquiries. An enquiry receives a reference and names the next step; applications, payments, compute allocations and registrations open only when their team, terms and review capacity exist.