One Health is a framework for understanding how and why our impact on the planet can put human and animal health at risk. Incidents like the hantavirus cruise ship and Ebola outbreaks remind us that the environment can affect our health in unexpected ways.
You may have followed headlines recently about a rare infectious disease called hantavirus after passengers on a cruise ship contracted a rare form of the virus (Andes strain) that can spread from person to person. This was followed by a WHO declaration of a public health emergency of international concern due to an Ebola outbreak in the Democratic Republic of Congo and Uganda [archived link]. While the risk to the general public outside of the affected regions remains low, spillover events (when diseases that normally infect animals infect human hosts) are occurring more often than in the past, and we can expect them to become more common [archived link]. That’s because climate change, the destruction of forests, and the growth of cities are increasing the number of wild animals that come into contact with humans.
What is One Health?
Source: US Geological Survey [USGS]
One Health is the concept that human health, animal health, and planetary health are all interconnected. The “one” in One Health implies that when one part is affected, the others will be as well [archived link]. Looking at human health in this context helps us to see the bigger picture and anticipate potential problems before they occur. For example, One Health principles helped us to understand the origins of the COVID-19 pandemic. Although we may never know the exact sequence of events that led to its emergence, we do know that horseshoe bats are a reservoir for SARS-related coronaviruses [archived link]. You can think of a reservoir species as a home base or natural habitat for a given germ that can cause disease. This usually isn’t a problem as long as bats and people stay away from each other, but when factors like deforestation, the illegal wildlife trade, and urbanization bring wild animals and humans together, sometimes the results are catastrophic.
Why is One Health important?
One Health teaches us that keeping people healthy requires us to look beyond the human world [archived link]. Ignoring One Health can lead to poor outcomes like spillover events, unsafe food and water, food shortages, and antibiotic resistance. One Health is also important because it encourages doctors, vets, scientists, and public health experts to work together, which can prevent outbreaks and lead to better, more lasting solutions.
Another reason One Health is important is that due to global travel and shipping, humans are more mobile than ever before. That means that if an outbreak starts on one continent, it has the potential to spread around the world. Worldwide shipping can also accidentally transport animals and plants to new places where they don’t naturally belong. This can threaten local wildlife or damage crops and other important food sources. The more often these events occur, the more risk there is for everyone.
How does One Health affect me?
One Health isn’t just about identifying potential threats, it’s also about finding workable solutions. For example, the American South once suffered from high rates of hookworm infection. Between 1865 and 1910, approximately 40% of people living in the southern U.S. are believed to have been infected with this parasite [archived link]. Hookworm infections can cause symptoms such as diarrhea, fatigue, iron deficiency, and impaired cognitive development in children [archived link]. Hookworm infections are now rare as a result of the first major public health initiative carried out in the U.S. The solution involved a combination of deworming and educating the population about proper sanitation. This campaign proved that large-scale public health interventions could be successful and eventually led to the founding of a national public health service.
The campaign to reduce the burden of hookworm infections is an example of a successful One Health intervention because it combined treatment with education, sanitation, infrastructure improvement, and collaboration between health authorities and local communities. While hookworm has never been fully eradicated, thanks to One Health measures it is no longer a major threat to human health in the U.S [archived link].
What can I do to protect my community and my environment?
There are some simple strategies to protect yourself and your community from zoonotic diseases (diseases that spread from animals to people) [archived link]. Most of these are common sense, and you’re probably doing a lot of them already!
✅ Vaccinate pets and supervise them when outdoors [archived link] ; pets can harm local wildlife [archived link] and come into contact with infectious diseases [archived link], which may spread to humans. While keeping pets indoors is not always practical, unsupervised outdoor time should be limited when possible.
✅ Take appropriate precautions when spending time outdoors, such as using insect repellent and avoiding tall grass and heavily forested areas.
❌ Never approach or handle a wild animal, especially if it appears hurt or sick; instead, call your local state wildlife management organization or a licensed wildlife rehabilitator to report sick or dead animals.
✅ Teach children to respect wildlife and inform them of the dangers they may pose to human health and safety.
✅ Use PPE (such as gloves and masks) when cleaning areas where animal waste or remains may be present, and wash hands thoroughly after.
✅ Wash and cook food thoroughly to avoid contaminants.
✅ When traveling overseas, check to see if additional vaccinations or prophylactic medications are recommended for the local region.
✅ Join a local environmental advocacy group to learn about threats to your community and get involved in the solutions.
Bottom Line: Becoming familiar with One Health can help you appreciate the many links between the environment and human health. Knowing about the risks of spillover events, taking precautions when you spend time outdoors, and learning about threats to your local environment are great ways to become responsible stewards of global health.
Stay well, stay safe.
Love,
Those Nerdy Girls
Resources and further reading:
AVMA – One Health
CDC – One Health Publications
CDC – National Center for Emerging and Zoonotic Infectious Diseases
EPA – One Health
FDA – One Health: It’s for All of US
Indian Journal of Community Medicine – One Health: A Holistic Approach to Tackling Global Health Issues
Johns Hopkins Center for Health Security – One Health
One Health Commission – One Health Library
Pathogens – The Importance of the One Health Concept in Combating Zoonoses
Tropical Medicine and Infectious Diseases – The One Health Approach: Why Is It So Important?
WHO – One Health Initiative
WOAH – One Health
