One Health in practice
One Health brings human, animal and environmental expertise together to investigate disease, control shared threats and protect the conditions supporting health. Its practical forms include joint outbreak investigations, animal vaccination, access to veterinary medicines, water management and conservation with local communities.
Shared outbreak investigation
Severe fever with thrombocytopenia syndrome (SFTS), a tick-borne zoonotic viral disease, illustrates collaboration between human and veterinary medicine in Japan. A woman in her fifties died after hospitalisation with fever, fatigue, vomiting, diarrhoea and low white-cell and platelet counts. Her doctors sought help from a veterinary infectious-disease laboratory, which isolated the virus in Vero and feline embryo cells; sequencing and real-time PCR at other veterinary laboratories confirmed the diagnosis.
Two cheetahs at a Hiroshima zoo also died with SFTS diagnosed from tissue samples. Tick bites were the probable source of the first infection, while transmission between cheetahs could not be ruled out for the second. After diagnosis, surviving animals received acaricides, and a 2020 account reported no subsequent SFTS in them.
Human cases without identified tick bites prompted investigation of other transmission routes and sentinel animals. In one Japanese prefecture, raccoon seroprevalence rose from zero to nearly 50% between 2007 and 2016, before multiple human cases appeared near the end of that period; surveys also included wild boar, deer and stray cats and dogs. Cases involving veterinarians and pet owners also prompted investigation of transmission from infected cats and dogs.
Evidence came from human clinicians, small-animal, zoo and wildlife veterinarians, virology, sequencing, disease modelling, tick biology and public health. Its evaluation informed campaigns for professionals and the public, including pet-owner information on risks and prevention, supporting recognition of disease and protection of people and animals.
Dog vaccination and rabies
Dogs account for up to 99% of human rabies transmission, making canine vaccination central to protecting people as well as animals. Fear of rabies can lead to indiscriminate killing of dogs. Rabies’ global annual economic cost has been estimated at US$8.6 billion.
By September 2023, Mission Rabies reported vaccinating 2 million dogs. A Cambodia campaign vaccinated 75,000 dogs over ten days; the programme aims for 70% coverage in project zones and ultimately rabies elimination.
In June 2021, the programme reported statewide rabies control in Goa, where it had worked since 2013. Activities combined dog vaccination, including 61,143 dogs in one 30-day period, education reaching 1 million people, and rapid-response surveillance. The programme reported no human rabies deaths in the state from 2018 through its 2021 announcement.
Access to veterinary medicines
The World Veterinary Association and animal-welfare organisation Brooke launched the first global essential-veterinary-medicines list for food-producing animals on 18 March 2024. It aims to improve access to safe, effective medicines and vaccines and support antimicrobial-resistance control and pandemic preparedness.
A survey of veterinarians reported that 80% of respondents felt medicine-access difficulties limited their capacity to manage animal health and welfare. The list offers a blueprint for countries to adapt to local diseases and pathogens, with improved zoonotic-disease control and pandemic prevention as intended benefits.
Eutrophication and shared water risks
Eutrophication links environmental conditions with animal and human health. Excess nutrients promote algal blooms, reducing light and photosynthesis in submerged plants; decomposition consumes dissolved oxygen, threatening fish and other aquatic species. Nutrients released during decomposition can support further blooms.
Cyanobacteria, commonly called blue-green algae, are photosynthetic bacteria, and some can produce toxins affecting the liver, nervous system, gut or skin. Not all blooms produce toxins. Boiling does not make cyanotoxin-contaminated water safe to drink. Environmental agencies use molecular, biochemical and analytical methods to detect cyanotoxins. Some pollutants can increase in concentration in organisms’ tissues as they pass up a food chain, a process called biomagnification.
Nutrient loading can come from agricultural runoff, aquaculture and concentrated feeding operations, industrial and residential runoff, and recreational activities. Natural processes also contribute, including biogeochemical cycles, sedimentation, groundwater seepage and runoff; eutrophication alone therefore does not establish human-caused pollution.
Measures to limit blooms should be feasible for those earning a living from the land, and farmers and other food producers should be consulted alongside other stakeholders. Farmers contribute knowledge of seasons, land, animal and plant behaviour, local requirements and production technologies.
Forest protection and community health
Logging and gold mining can connect forest destruction to health risks, including mercury entering rivers used by wildlife and communities for drinking, washing and fishing. Junglekeepers, an indigenous-led conservation organisation based in southeastern Peru, seeks to protect the Las Piedras river corridor and connect the Alto Purus, Manu and Bahuaja Sonene national parks.
In 2025, the organisation described two complementary strategies:
- Acquire government concession titles from the government or existing holders using donations; the titles last 40–50 years and locally are predominantly for Brazil-nut harvesting.
- Steward the land through a ranger programme that trains and hires exclusively local indigenous people, with fair wages, healthcare and childcare.
A small ecotourism operation also employs community members and supports local artisans. The organisation reported raising US$3 million in the preceding year, roughly doubling its reserve to 110,000 acres towards a 300,000-acre goal, but spending more on defending land than acquisition in 2025 as destruction accelerated.
It also reported acquiring land bordering a reserve for uncontacted peoples to buffer them from encroachment and exposure to outside pathogens. Environmental education for community children and wildlife research partnerships complement protection, although defending land constrained its ability to fund research.
The organisation argues that any medicinal-plant research should respect indigenous ownership of knowledge and benefit local communities, avoiding the exploitation associated with earlier extractive industries.