One Health recognizes that the health and medical outcomes of people are closely connected to the health of animals and the planet. One Health is strongly focused on collaboration across different sectors. Doctors, scientists, veterinarians, policymakers, nurses, epidemiologists, agricultural workers, pet owners, law enforcement, ecologists, wildlife experts, communities, and more work together to organize their efforts across their fields to ensure the best outcomes for humans, animals, plants, and the planet.

One Health recognizes that when humans interact with areas untouched by people, it will impact an entire system that includes humans, plants, animals and the planet. This occurs at local, regional, national, and global levels.

The One Health concept goes back at least two centuries, with different names over the years (like One Medicine; then One World, One Health; and finally One Health since 2003-2004). Now, the world's focus on the interconnection of health between its living beings is being talked about more than ever.

One Health has become more popular due to changing interactions between various living groups. This is because of the impact of humans on new geographic regions, which has resulted in people living closely next to wild and domestic animals.

We have relationships with animals in a number of ways, including for food, travel, sport, trade, education, livelihoods, fiber, and companionship. It's through these relationships that diseases have the potential to pass between animals and people.

Animals today have fewer habitats that are safe from development or the consequences of people. This is because of humans' impact on the environment through climate change, migration, deforestation, farming, pollution, and other uses of land.

These interconnected forces have caused new and existing diseases to spread from animals to humans (also called 'zoonotic' diseases). Different types of zoonotic diseases include:

• West Nile virus
• Rabies
• Salmonella
• Ringworm
• Lyme disease
• Ebola
• Q Fever (Coxiella burnetii)
• Plague
• Influenza
• Emerging coronaviruses (such as SARS and MERS (Middle East respiratory syndrome))

Similarly, animals can be sickened by some human diseases or from environmental hazards. An example of this is when humans might dump liquid waste from a production factory into a local stream. This can poison or kill fish, kill the plants in the local water sources, pollute the soil, and potentially lead to high levels of those same chemicals in the fish humans eat.

Sometimes the same elements that make animals sick can serve as a warning for what can make humans sick. An example of this is birds dying of West Nile virus, serving as a signal that people in the same area might become infected soon.

Other One Health issues include - antimicrobial resistance - food safety and security - environmental contamination - vector-borne diseases - other shared health issues

Experts are now looking at the fields of chronic disease, occupational health, mental health, injuries, and noncommunicable diseases through the lens of the One Health approach. For instance, fighting and preventing the spread of a disease that kills many animals might help prevent that disease from hurting humans and the environment in which those animals live. This is why groups like the United States Centers for Disease Control and Prevention (U.S. CDC) monitors public health threats and studies how diseases spread between people, animal, plants, and the planet.

The One Health approach partially focuses on emerging zoonotic diseases. COVID-19 has been a large focus of many scientists in the last 18 months, due to its potential origins as a zoonotic disease. Experts are still unsure of how SARS-CoV-2 first began spreading between humans, but the potential of the disease or other types of coronaviruses transmitting between animals and humans is high.

The impacts of human-caused climate change on the planet's flora and fauna, animals, and humans have been well documented for the last 50 years, and yet the Earth's population is still projected to reach 9 billion people by 2050. Roughly 75% of all emerging human infectious diseases the last 30 years originated from animals and environmental damage may impact the lives of 3.2 billion people and potentially hundreds of billions of plants and animals. The cycle of humans impacting environmental and animal health (which then impacts human health) will continue to be reinforced if climate change is not met with a focus on health outcomes for each of these groups. A One Health perspective aims to do just that by working alongside experts from each field to combat these threats and promote the well-being of each member of the Earth's ecosystems.