Tear Down the Ivory Walls: Connecting Human, Livestock and Ecosystem Health

For a lot of students (myself included), the phrase ‘environmental health’ mostly calls up images of pollution. It means contaminated rivers, smokestacks, fumes inhaled by welders, cancer rates for pesticide sprayers and their families.

But the phrase also includes problems of infectious diseases and how they move through the world. How do viruses like the flu morph and travel, spreading from isolated cases into a global pandemic? Where are the breeding grounds in which diseases are most likely mutate and recombine? How do pathogens and parasites travel between farm animals, wildlife, people and back?

Problems like these are complex, in large part because they occur in an ever-tightening web of global economic and travel connections. As Dr. Greg Gray pointed out in his recent visit to our Environmental Health class, we can now eat a sandwich for lunch with ingredients sourced from 4 different continents without batting an eye — or having any meaningful idea of from where (and through what) this food has traveled to reach us.

News stories about global outbreaks of diseases like avian and swine flu also speak to these connections: as agriculture shifts on a global scale toward larger operations and denser feedlots, pathways are being strengthened that bring people, animals, drinking water, etc., into closer contact with each other. It’s also easier than ever before to move people and things around the world, potentially carrying pathogens along for the ride.

These tighter connections also mean that unhealthy practices in one arena (for example, the practice of mixing powerful last-line-of-defense antibiotics into the standard feed in pig farms in Vietnam) are more likely to have catastrophic repercussions elsewhere — say, for farmers and others who end up infected with variants of the drug-resistant bacteria that result.

So how do we study problems like these that don’t fit into a neat area of specialization? The One Health Initiative aims to help.

One Health is a global framework for working on health questions in a way that crosses several traditional academic disciplines. Research under the One Health umbrella is problem-oriented, not specialty-oriented. This work isn’t just biochemistry research, or veterinary medicine, or human medicine, or epidemiology, or transportation analysis, or ecosystem science. It may require active inputs from many or all of these fields, and require active collaboration across groups that might not naturally interact with one another — including the farmers and herders who are most directly affected by animal-borne disease (and by the economics of any proposed solutions).

Dr. Gray noted that it’s been harder in his experience to get human medical experts to buy in to the value of this kind of collaboration, compared to researchers in animal health and ecosystems (who in many cases are already trained to think in a relatively systems-oriented way). In some sense, One Health at its core may be a wider lens for looking at the world: an awareness that all problems have both causes and consequences, some of which we cannot directly observe without the help of others. Its focus is on interconnections between issues like disease movement, the global food and water supply, and antimicrobial resistance; the potential value of such a cross-cutting lenses across other types of problems, however, cannot be overstated.

In 1956, science-fiction genius Isaac Asimov wrote a short story about cross-disciplinary science. In the world of this story, characters face deliberate hindrance by government bureaucracy as they attempt to work beyond their own narrow, assigned specializations. (To be fair, the eventual cross-disciplinary technology forged by Asimov’s rebellious researchers ends up disrupting the fabric of global society in a very regrettable way.)

Pushing for interdisciplinarity in science isn’t a new idea, but it’s one much easier invoked than achieved. For one thing, gaining meaningful expertise in a field requires an enormous investment of time and energy into the details of that field — namely, it requires specialization. Interdisciplinary studies are not terribly useful if they only draw on shallow perspectives on each field. But that specialization, in turn, can lead to de facto walls between the experts in various fields, unable to comprehend (and largely unaware of) one another’s work.

Sometimes the result of this siloing borders on hilarious. In 2007, a medical researcher was the subject of a brief internet dustup when their paper developing a “new method” of measuring the area under a glucose curve appeared to reinvent a tool of basic calculus — and was subsequently cited hundreds of times by other members of the field. While an unusual example, a story like this does beg the question: how many researchers have devoted time and resources to solving problems that have already been solved by a colleague in the next building over?

On the other hand, the boundaries between disciplines can be extremely difficult to cross, even by those fighting to answer shockingly important questions. Take the story of Irakli Loladze, a mathematics Ph.D. who became obsessed with urgent questions about how rising CO2 levels seem to be making our basic staple crops less nutritious. A great article from last year detailed the struggle he and others have had to even be taken seriously for asking a biology question as a mathematician, or vice versa — much less to get funding to study that question, from grant sources for either math or biology.

What does One Health actually do combat any of these problems? It’s much more than just declaring that health is a system and publishing a few infographics. One Health supporters, from individual researchers to the CDC to the National Pork Board, work in institutions around the world to research and implement local and global best practices for animal, food and water safety then communicate those findings to the people and governments that need them. They develop international meetings, training workshops, student curricula and now even whole degree tracks that focus on approaching the problems One Health seeks to address from its multidisciplinary angle. This not only draws attention to these issues, but provides health providers, veterinarians, farmers, researchers and policymakers with concrete resources to deploy One Health insights.

As the world gets smaller, we need deep specialists. But we also need to be building meaningful infrastructure that bridges the gaps between these specializations, and to support those who are compelled to work across boundaries. This is true not just within the natural sciences, but reaching from science into the realms of economics, sociology and beyond.  It’s not enough to wish for better interfaces: those who are serious about such work will have to help pull resources and attention into the spaces in between fields, where today’s most complex and compelling problems lie. In light of this pressing need, the One Health initiative is a model worth studying.

Photos: Greg Gray for Duke One Health. Venn Diagram graphic: UC Davis. Video: U.S. Centers for Disease Control and Prevention.

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