Professor Malcolm Bennett, University of Liverpool School of Veterinary Science
“Recently I’ve been involved in several One Health events, not least a conference, One Health: breaking boundaries and crossing scales, hosted by the University of Georgia, Athens (USA). The conference was very successful – it brought together provocative and knowledgeable speakers who spoke, often with passion, on subjects ranging from disease and poverty to food-borne infections, conservation and disease evolution.
Over meals, beer and in a general discussion on the final day, we discussed what One Health means, and, despite giving several talks myself on this to very different audiences, I confess that I’m still not completely sure.
The Wordle above is based on the top six One Health hits on Google (I removed the words ‘One’ and ‘Health’): from this it’s clear that One Health is about animals and human beings (who are, of course, animals), and the environment (which we all share) and interdisciplinarity and working together to make things better.
But perhaps it’s the rarity of some words that is most striking: ‘climate’, ‘plants’, ‘global’ and ‘agriculture’ get only two mentions each across all six sites. And there is only one mention each for ‘economics’/’economists’, ‘society’/’social’, ‘epidemiology’, and ‘sustainability’ (plus one for ‘chiropractors’).
An oft-cited near-definition comes from the report on a meeting in New York around ten years ago, sometimes referred to as the ‘Manhattan Principles on One World, One Health’.
One Health asks that we recognize the essential link between human, domestic animal and wildlife health and the threat disease poses to people, their food supplies and economies, and the biodiversity essential to maintaining the healthy environments and functioning ecosystems we all require.
Many accounts (the Wikipedia entry is a good example) claim a history for One Health that argues for a direct lineage back to Hippocrates, mainly because he emphasised the role of environment in disease (not that he had much else to go on), and, more recently, Rudolph Virchow who famously said ‘Between animal and human medicine, there is no dividing line””nor should there be.’
Virchow also coined the term ‘zoonoses’ (currently taken to mean infectious diseases transmitted between human animals and other vertebrates) although he didn’t define it and didn’t believe in Pasteur’s then revolutionary germ theory. Then again, part of his dislike of germ theory was that he felt it underestimated the role of the environment and social factors in disease. I’m not sure if that makes him right for the wrong reasons or wrong for the right ones.
The historical argument goes on to suggest that the recent compartmentalisation and specialisation of biomedical sciences is merely a blip. One Health has always been and will always be the true path; we have merely temporarily strayed into our silos. And, of course, there’s nothing like a touch of the ancient Greek for adding philosophical legitimacy to a struggling idea.
Ecosystem services approach
Actually, I don’t mind there not being a single, agreed definition, as if there were one it would constrain the meaning by cutting out something important. I see One Health as being part of an ecosystem services approach, in which health is a simply part of the overall aim of improved human ‘well-being’.
One Health requires an interdisciplinary approach (which in turn requires the existence of disciplines), but of more than just the medics and vets of ‘One Medicine’. An ecosystems approach encourages us to trade off health against the other things we get from living on a shared planet, a notion still anathema to most medical and veterinary ways of thinking, in which disease exists only so that we can destroy it at almost any cost.
The idea that people might be willing to put up with a degree of disease because they (for example) like the view is dismissed, even if this is how each of us lives our daily lives.
One problem with an ecosystem services approach is that it is so economics and human-centred. I was pulled up on this at a recent public lecture on One Health in Atlanta. Why, I was asked, did I bang on about what drives people rather than simply argue from an ethical perspective? Where were my values (the price of everything and the value of nothing)?
Another problem is the actual doing of it. Funders and institutions tend to be discipline-based, and to expect excellence in their own area rather than accepting that sometimes two or more elements of good activity might lead to excellence at the interface. Some disciplines find it easier to work with ‘outsiders’ than others.
Furthermore, we all speak different languages and have our own dogmas and cherished ways of doing things, not to mention discipline-based peer-review and careers. So trans-disciplinary communication and respect can be problematic.
Several years ago I set a group of students the task of writing an essay entitled, simply, ‘One World, One Health’.
One world, one health – last chance?
One of the students ended her essay with the line, ‘One World, One Health, Last Chance’. I thought this was pretty cool, and for a few months would end my lectures with that line, sometimes gazing upwards with my hand on my heart like an American listening to the Star-Spangled Banner. The first time I did this someone came up to me afterwards to tell me, in tears, how wonderful my talk had been.
I subsequently learned from my colleagues that she had been drinking heavily, however, and I noticed that other audiences would smirk and sometimes openly laugh. I asked my wife about this and she maintains it’s because I ‘can’t do sincerity.’ She may be right but more importantly, it’s not true, of course – it’s not our last chance.
Civilisations have fallen and disappeared in the past, economies crash and it’s not nice but somehow, somewhere, human beings always muddle through.
So I suppose that in the end I think that One Health, through its interdisciplinary and global approach, its recognition that we human beings are animals sharing an environment, and its understanding that health and wellbeing can, perhaps must, be applied to more than just us, provides a route to something better than just muddling through.”