At the start of her graduate studies at the University of Guelph’s Ontario Veterinary College in 2018, Sydney Pearce presented her research on improving antibiotic use in the dairy industry at a conference. She spoke of animal health, human behaviour, the social determinants of health and the environment.

“That sounds like One Health to me. Are you doing One Health?” an audience member asked. Ms. Pearce hadn’t heard of this approach before (although it had been added to U of Guelph’s strategic research plan a year earlier). One Health tackles animal health, human health and environmental problems with an interdisciplinary approach, involving collaborations between researchers in the sciences as well as social scientists, plus people in government and industry.

“One Health says that certain problems are complex, and if we have a complex problem at the intersection of human, animal and environmental health, that can’t be solved by one person in one discipline,” says Cate Dewey, associate vice-president academic and director of the One Health Institute at the U of Guelph. The institute includes 140 affiliated faculty members from across the university. It was founded in 2019, around the time Ms. Pearce transitioned from a master’s in epidemiology into a PhD in epidemiology and One Health. Focusing on this gave her “the ability to have a structured way of looking at the big picture,” she says.

One Health’s systematic, multifaceted approach to solving problems avoids health initiatives and interventions that don’t work effectively in real life. Consider COVID-19 vaccines: It took medical and veterinary researchers to develop them, governments and industry to make and distribute them, but also required those who understand socioeconomic barriers and psychology – working with municipalities and community groups – to entice more people to get a shot.

Ms. Pearce began collaborating with experts from different disciplines even more. She conducted a review of nine journal databases and discovered the number of articles using the One Health methodology was rising steeply (from two in all of 2010, to 60 in the first six months of 2021). She also founded the One Health student committee. Two hundred students registered for the inaugural event late in 2019, with nearly 50 applying to be on the advisory board. “There was a lot of excitement; people really connected with it,” says Ms. Pearce.

U of Guelph launched a collaborative specialization in One Health in 2020, allowing students to embark on a master’s or PhD in any one of 18 departments, blending that with coursework and a thesis focused on the approach. This fall, the university went all-in, launching the bachelor of One Health, the first standalone undergraduate degree on the subject in Canada, accepting 52 students from over 300 applicants. It’s run out of the college of biological science in collaboration with three other university faculties.

“Suddenly, everybody wants to be doing One Health at every level,” says Patrick Leighton, a professor of epidemiology and public health in the faculty of veterinary medicine at Université de Montréal. COVID-19, and suspicions that it was initially transmitted to humans from animals, nudged this approach into the mainstream. It has grabbed the attention of students, who say the approach makes sense and develops in-demand job skills, as well as researchers who want to do big-picture work that could make a difference.

Origin and history

In many ways, the approach is centuries old. “It’s not this crazy, wild new idea. It was recognized by the ancients. For example, First Nations have a very intuitive understanding of One Health,” says Emily Jenkins, a professor at the University of Saskatchewan’s Western College of Veterinary Medicine. In the 20th century, “One Medicine” became the preferred way to describe how animal and human health are linked. “Ecosystem approaches to health” then became popular (a concept that’s still used today). The moniker One Health emerged around 2004, during the SARS outbreak, and for some reason has stuck.

Part of the reason that One Health has grown in popularity is that by the early 2000s, there was greater recognition that such an approach was necessary to fully understand and tackle the multiple contributing factors to health crises such as the fatal E. coli outbreak in Walkerton, Ont., or outbreaks of avian flu and West Nile virus, zoonotic diseases that spread between animals and humans. Plus, there’s the growing risk of antibioticresistant infections. A report by the Council of Canadian Academies estimated that 5,400 people died in Canada in 2018 alone from what’s formally called antimicrobial resistance, a problem driven by both human but mainly animal overuse of antibiotics.

In 2008, a strategic framework around infectious diseases focused on One Health was created by the World Health Organization (WHO), the World Organisation for Animal Health and other major international groups. In the United States, the Centers for Disease Control and Prevention established the One Health Office as part of its National Center for Emerging and Zoonotic Infectious Diseases division in 2009. The first International One Health Congress was held in 2011, and groups such as the One Health Commission and the One Health Global Network began launching.

At Canadian universities, activity in the area began in earnest around this time. At U of S, One Health was declared a signature area of research in 2011 (and was renewed in 2022). Université de Montréal made One Health a strategic research focus through its One Health Initiative this year, though faculty members have been leading projects using the approach for some time, through the Centre for Public Health Research and the Epidemiology of Zoonoses and Public Health Research Group.

Dr. Leighton, an ecologist by training, is a member of both and is also director of the Canadian Lyme Disease Research Network. He says that Lyme disease is a “perfect example” of a One Health issue because it involves the intersection of wildlife, natural and social environments, and human health: Infected ticks invade public parks, which creates a health risk for the humans and animals using these spaces. One project run by the research network in a park in Bromont, Que., involves treating mice with a pesticide via bait stations. The goal is to prevent mouse-to-tick transmission of the disease and its spread to other animals and people. The project has buy-in from the city and community groups to find ways to encourage behaviour change, such as staying on trails and doing tick checks after a walk in the park.

At the University of Calgary, a project launched in 2020 involving members of the institution’s One Health research group looked at a COVID-19 outbreak at an Alberta meat-processing plant. Researchers are seeking to understand the cause of the spread, the response and to also collect stories about the employees, all in collaboration with the research subjects and their union, says Herman Barkema, a professor of epidemiology of infectious disease at the university and director of the group, called One Health at UCalgary.

But work that uses this approach can look at the big picture too. Arne Ruckert is an international development researcher at the University of Ottawa and also the research co-ordinator of the Global 1 Health Network, a research group focused on infectious diseases and antimicrobial resistance. In 2021, he co-authored a brief that urged the WHO to include the approach in its planned pandemic treaty, which would set up international rules around sharing health information and pandemic readiness. “We argued that without some kind of global One Health structure that assesses the health capacities of countries, you won’t know to what extent countries have the capacity to co-ordinate a policy response when there is a pandemic,” he says.

In the lecture hall

The skills that students learn in One Health studies are useful for conducting research in the area, but they’re also in demand in government, health care, international relations and beyond. “You train people to think in a different way,” says Dr. Leighton. “You train them out of thinking in disciplinary silos and into approaching a problem from a systems point of view.”

That’s one reason why universities beyond U of Guelph are also focused on exposing students to these concepts. One of the first such programs in Canada was the undergraduate Certificate in One Health at U of S. Launched in 2014, it ran for eight years with funding from a Natural Sciences and Engineering Research Council of Canada grant. Dr. Jenkins says the school is aiming to get a new grant to create a similar One Health training program focused on bio-preparedness.

“You train people to think in a different way. You train them out of thinking in disciplinary silos and into approaching a problem from a systems point of view.”

Western University’s Schulich School of Medicine and Dentistry added an honours specialization in One Health to its bachelor of medical science in 2018, allowing students to take core courses on the topic and do a final-year thesis and research project with a supervisor from various departments across the university. “The demand keeps increasing,” says Francisco Olea-Popelka, Western’s Beryl Ivey endowed chair in One Health, a position he took in 2019.

Upon his arrival, he began offering two third-year courses on the subject for medical science students, including those in the specialization, and had to keep expanding enrolment to meet demand. For the 2021-2022 school year, the introductory course, Foundations in One Health, had 60 students with 40 on the waiting list (120 students are taking it in fall 2022). Western introduced the One Health Major in 2021; intended to be part of a double-major program, it lets students combine studies in this area with another focus of their choice. Dr. Olea-Popelka loves that students are on board with One Health, which he sees as a more effective way to look at problems, pushing against university silos. “I want to change the entire culture of education and health and medicine,” he says.

At the University of Calgary, Dr. Barkema and others are developing master’s and PhD programs that are slated to start in 2024. He says these degrees, and the two-week One Health Summer Institute it ran in 2022, are conducted in collaboration with Indigenous groups. U de Montréal is also putting together a PhD program that will complement the school’s master of public health program, which already allows students to take a concentration in One Health.

As a first, the University of Prince Edward Island will incorporate a planetary health approach (which deals with how humans impact the planet) in its medical school, which will launch in 2024. “At UPEI we have a veterinary college and now there’s a school of climate change, so it seemed appropriate to have that focus,” says Laurie McDuffee, professor in the department of health management with UPEI’s Atlantic Veterinary College.

Canadian medical schools appear likely to follow. One sign is that the Association of Faculties of Medicine of Canada will add planetary health competencies in its curriculum update in 2025. (Planetary health is a similar approach that more fully incorporates environmental issues.) Dr. McDuffee notes that dealing with climate anxiety and responding to weather-related disasters are increasingly central to the role of a healthcare provider.

‘It’s not enough’

But outside of these programs, and away from vet schools, few students are exposed to One Health, even when it’s relevant to their disciplines. At what stage it’s best to offer students skills related to the approach is up for debate. “We’re not creating an undergraduate degree,” says U of Calgary’s Dr. Barkema. “We’re reluctant because we don’t want to create a jack of all trades and a master of none.”

One barrier to getting students and researchers into One Health is the nature of university structures. “We have silos. Right now, veterinary students and medical students typically don’t even have one class together,” says Dr. Barkema. “We are not taught to work together.” As a result, academics struggle to even communicate with each other effectively. “We turn each other off with our jargon. Even finding a common terminology and ground to connect with people across disciplines is a real challenge,” says Dr. Jenkins.

“One Health is action-based. It’s not just to learn, but to attain better health outcomes for humans, animals and the environment.”

With vets often taking the lead in One Health projects and directing the agenda, it’s difficult to get others, such as social scientists, to join. “We need social scientists but are we engaging them?” asks Ms. Pearce. “It has to be meaningful for them. It needs to improve their work.” Without their input, One Health becomes less effective. “You need to have a strong social science component. Around 75 to 80 per cent of all health outcomes are determined not by biological or genetic factors, but social determinants,” says Dr. Ruckert.

To have impact, the approach also needs to inform on-the-ground projects. “One Health is action-based. It’s not just to learn, but to attain better health outcomes for humans, animals and the environment,” says Western’s Dr. Olea-Popelka. That takes commitment over time. To take One Health projects to a higher level, researchers need a clearer path to earning grants. Currently, funding agencies are as siloed as universities. “One Health falls between the cracks of Tri-Council funding,” says Dr. Leighton. There have been one-off calls for funding, but One Health-focused proposals in regular rounds can be penalized for being too multidisciplinary.

Researchers could gain access to stable funding if Canada had a national strategy in place, according to a 2022 policy brief about preventing zoonotic outbreaks, written for the Royal Society of Canada. Dr. Jenkins says there have been talks about creating a national institute, but it’s being led by vet schools. “Why should medical colleges and others get engaged in this? We have a ways to go to get people to see that they have a place at the table,” she says.

If there is to be a move to get One Health recognized nationally, the time is now, while COVID-19 still lingers and the human-animal-environmental connection feels urgent. “There’s a lot of buy-in right now,” says Dr. Ruckert, who predicts public interest will wane, particularly if research-driven interventions fizzle. “There will be no immediate, cheap solutions.”