In 2008, my colleagues and I published a brief article about the need to teach One Medicine, One Health to medical students. Our article covered why One Health education was important, but we didn't discuss how to incorporate it into curriculums. The subject is vast and can be approached in many ways.
Much has happened since 2008 including a deadly global pandemic, worsening antimicrobial resistance, and diminishing food security among other threats. The need for widespread education and adoption of One Health has never been greater. Of course, how the subject is taught depends on the students—their ages, their educational backgrounds, their interests, their career goals, among other considerations.
I recently had the pleasure of introducing the One Health concept to the faculty and students at the Department of Health and Behavioral Studies at James Madison University in Harrisonburg, Virginia. The faculty wanted to know how to incorporate the concept into their courses and curricula. For the students, I presented a One Health exercise.
For university faculty, examples of One Health subjects are listed below. Ideally, these topics should be taught at microbial/cellular, individual, and population levels. (To visualize, see the One Health Rubik's Cube)
Below, I've listed brief descriptions of some of these subjects.
Chronic Diseases and Comparative Medicine
Evidence suggests that microbes such as Brucella species, Helicobacter pylori, Human Papilloma virus, Epstein-Barr virus, and certain fungi can trigger, either directly or indirectly, several chronic diseases in humans and animals. In addition, animal genomes, such as canine genomes, can provide important information on the genetics of human diseases. The book, Zoobiquity, describes some of the overlapping features of chronic and psychiatric diseases in humans and other animals.
Human, Animal, Plant Microbiomes
The gut microbiome is as important for health and well-being as any organ. The plants and animals we call food influence our gut microbiomes. Alterations to microbiomes, such as diet, illness, or antimicrobials, can lead to dysbiosis which can cause disease. Understanding these interactions is crucial to providing effective healthcare. Plant microbiomes are as important as the microbiomes of animals. Farmacology and The Jungle Effect are good reference books for examining this subject.
Antimicrobial Use and Resistance, Bacteriophage Therapy, Vaccines
Antimicrobials, antiseptic practices, and vaccines are the foundation of modern medicine. While antimicrobials have saved countless lives, they have come with costs namely adverse effects on microbiome health and worsening antimicrobial resistance. Strategies, such as bacteriophage therapy, to counter the adverse effects of antimicrobials should be a priority. The importance of vaccines in preventing diseases in humans and other animals must be emphasized. Vaccines are one of the greatest discoveries in the history of medicine, public health, and animal health. Missing Microbes and The Perfect Predator are informative books.
Zoonotic Diseases
Approximately 60 percent of human infections originate in other animals. Many of the newly emerging infectious diseases, such as avian influenza, Hantavirus, and plague are zoonotic. Zoonotic pathogens include bacteria, viruses, parasites, fungi, and prions. There are many causes of natural spillover events and much has been written about them over the past several decades. Developing effective policies to address the practices that promote disease transmission has been a challenge because many are linked to food security needs.
Biosafety, Biosecurity, Bioethics
Gain-of-function research on pandemic potential pathogens has generated considerable concern over biosafety, biosecurity, and bioethics. The origin of Covid-19 remains unsolved although circumstantial evidence indicates that the pandemic began with a laboratory accident. My book discusses these issues. The global community needs to decide if the benefits of having high containment laboratories conducting dangerous research in densely populated areas outweigh the risks. There must be stringent global oversight of these laboratories and the research being conducted in them.
Epidemiology, Disease Surveillance and Control
Epidemiology is a standard population-based, public health subject that must be included in any One Health curriculum. Understanding epidemics, epizootics, disease and mortality rates, vital statistics, disease transmission modalities and surveillance strategies, and the term R0 is essential. Integrating surveillance systems across humans and other animals is essential for a One Health approach to disease control. Large wildlife die-offs could be a sign of environmental contamination or ecosystem disruption. They must be investigated to determine the cause of the deaths.
Vector-borne Diseases and Vector Control
Mosquitoes are the deadliest creatures on Earth. Different species carry specific disease pathogens. For example, both Aedes aegypti and Aedes albopictus (aka Asian Tiger mosquito) spread yellow fever, dengue fever, and chikungunya. Anopheles gambiae spread malaria. Ticks spread different diseases. A bite from the Ixodes scapularis (aka deer tick or black-legged tick) can cause Anaplasmosis, Babesiosis, Ehrlichiosis, Lyme disease, Borrelia miyamotoi disease, and Powassan virus disease. Many factors influence the distribution of vector-borne diseases including climate change which has allowed the vectors to expand their range. As the planet continues to warm, the situation is anticipated to worsen. Compelling books to read are The Mosquito and Bitten.
Diet, Nutrition, and Exercise
When we eat, we feed not only our cells but also our gut microbes. Our gut microbes prefer high fiber foods such as vegetables, fruits, and whole grains. They do not like ultra processed foods with refined sugar. Feeding gut microbes a Western diet consisting of highly processed foods results in dysbiosis and metabolic diseases. Exercise is important for metabolic health. Animals, including humans, evolved to move. Contracting skeletal muscles release myokines that are important for the proper functioning of endocrine organs. Inactivity is deleterious to health. People who don't exercise regularly become vulnerable to sarcopenia (i.e., muscle wasting) particularly as they age, which can result in frailty, injury, and premature death.
Food Safety and Security
Agriculture and the food security it provides is the foundation of civilization. A safe, accessible, and secure food supply is essential for individual and societal survival. Ruminants and crop agriculture relying on synthetic high nitrogen fertilizer release methane and nitrous oxide, two extremely potent greenhouse gasses, respectively. Agriculture contributes to climate change and is threatened by it. Without a stable, predictable, relatively mild climate, agriculture cannot continue. Crops cannot grow in extreme heat, drought, or storms with flooding. When climactic conditions change, such as during the Little Ice Age (roughly 1300 to 1850), crop failures and famine resulted. Worthwhile books to read include: Timefulness, Nature's Mutiny, and Global Crisis.
Sanitation and Hygiene
Removing fecal wastes through sanitation systems and ensuring clean drinking water are fundamental for healthy societies. It took over a century for Western countries to implement sanitation systems. (Ancient Rome was famous for its public toilets and aqueducts). Nevertheless, in the 21st century, millions of people still lack access to basic sanitation and practice open defecation. In addition, no sanitation system is designed to process the wastes of domestic animals. Animal manure management does not get the attention that it deserves. Domestic animal manure contaminates environments and ecosystems contributing to disease. Animal fecal matter adversely impacts human health. Billions of domestic animals produce trillions of tons of manure. Manure lagoons are vulnerable to leaks and spills, particularly during storms. Manure lagoons also emit greenhouse gasses.
Animal and Horticultural Therapy
People rely on animals and plants for their mental and physical health. Animal assisted therapy increases physical activity, lowers blood pressure, reduces stress hormones, and increases healthy hormones such as oxytocin. The human-animal bond is mutually beneficial for both partners. Animal-assisted therapy helps people cope with many difficult conditions and situations. Along similar lines, plants, gardens, and nature benefit health. The Japanese term "Shinrin-yoku" means "Forest bathing." The Japanese recognized that spending time in a forest is therapeutic. Horticultural therapy is a relatively new term that uses gardening to improve health. A highly recommended book is Braiding Sweetgrass.
Environmental and Ecosystem Health
The terms environmental and ecosystem health are often used interchangeably, but they are quite different. Environmental health refers to the abiotic (i.e., non-living soil, water, and air) aspects of defined geographic areas. In contrast, ecosystem health refers to the biotic (i.e., living microbes, flora, and fauna) interactions of defined geographic areas. Environmental health typically addresses contamination from heavy metals, toxic chemicals, radioactive wastes, and other inorganic pollutants. These terms can apply to both indoor and outdoor settings. Air pollution is an environmental health issue. Ecosystem health is less well studied and involves the management of natural resources and biodiversity. Of course, environments and ecosystems impact each other. A "bioindicator" is the use of certain species to indicate the quality of the environment in a geographic area. For example, some insects, amphibians, and fish are more tolerant of pollution than others. The absence of creatures that are sensitive to pollutants could indicate a contaminated environment. Understanding these interactions is vital for health and sustainability.
We incorporate our environments and ecosystems into our bodies everyday by breathing air, drinking fluids, and eating the plants and animals we call food. If any of these are contaminated or polluted, we get sick.