Research Impact


Ep. 10: Where research transforms links between nature and health

Hear about how human health is linked to the health of the planet, and how UCL climate and habitat research is helping doctors and policymakers predict (and maybe prevent) the next pandemic.

Host and Producer

  • Dr Rosie Anderson, Research Fellow, Public Health Policy team, UCL


  • Professor Kate Jones, Centre for Biodiversity and Environmental Research, UCL
  • Dr Chris van Tulleken, Division of Infection and Immunity, UCL and Hospital for Tropical Diseases, London


Rosie Anderson  0:05   

Hello and welcome or welcome back to the podcast where research transforms lives. I'm Dr. Rosie Anderson and every Thursday the summer, I'm inviting you to take a deep dive with me into the UCL research that has changed the world around you. This episode we're talking about the ways human health is intertwined with the health of every ecosystem, and every other living thing on earth. While it's been a pretty established fact that poor living conditions will make you sick since the time of John Snow. No, not that John Snow, the Victorian epidemiologists, John Snow. It's only been in recent years that we started to realise how destroyed landscapes, habitat loss and climate change increase our chances of getting ill. That's a pretty mind blowing idea, and not without its controversies as well explore. More than anything though. It's complex and hard to measure and predict. That's why Professor Kate Jones of the Centre for biodiversity and environmental research at UCL has spent her career identifying the risk factors for human health when ecosystems are damaged, and mapping hotspots where diseases are more likely to flare up. In particular, she has helped governments and international agencies monitor zoonosis, where infections jumped to humans from another species. Kate and I spoke with Dr Chris van Tulleken, who you may know from his work on TV and radio, but he was also a researcher and clinician at UCL looking at infectious diseases, about how this poses huge challenges for him and his colleagues, as they tried to stay ahead of emerging pandemics like the one we've just lived through. And how Kate's research is key to preventing them happening in the first place. After all, can any of us truly be healthy? If we live on a dying planet? Chris, let's start with you. Because I want to know, as a clinician as a practising Doctor, how did you become interested in this whole thing of diseases jumping from species to species and especially humans to animals? I guess. 


Chris van Tulleken  2:05   

So. My, my PhD was in was in how can I do this? How can anyone make their PhD interesting, my PhD was was was looking at the differences between the HIV related viruses that infect non human primates and the main HIV one that infects human beings that's responsible for for pandemic HIV. And I was studying one of the little molecules that HIV carries around with it as part of its toolkit to get inside our cells and, and hijack them for its own ends. And so I was studying, I was studying the VPR molecule from SIV Mon, which is the Simian immunodeficiency virus from a moaner monkey. And it turned out when I went back through photographs from a decade earlier that I had lived for a period of time, at the the borders, where the borders meet from Central African Republic, and Republic of Congo, and Cameroon. And this is where I had been living with remote community of people called the bio hacker. And I'd been learning much more from them than they were from me. And I'd been been trying to work a little bit as a doctor. And this is the place where HIV jumped from. A chimpanzee was sure it was a chimpanzee to a human being, it's near a place called Melinda. And while I was there, we ate everything that they ate, and the main monkey it turned out that we had been eating because this was this is the diet of people who live in forest was a mono monkey. And so there's this sort of strange, you know, I mean, I'd love cake to explain it. But to a scientist, it's very unsettling when these things happen, because it feels like there's some morphic field in the universe that has meant my whole life was being organised towards studying the monkey that I'd once eaten. But, yeah, so. So I'd spent time in the forest at the site with the community of people at the place where HIV jumped and I think from that experience, I was really interested in how pathogens make their way from the the natural world into the human world. 


Rosie Anderson  4:28   

It's interesting because that's one of the big go to examples as an HIV when it comes to this kind of phenomenon. But as somebody who's practice medicine, you know, there's there's something which crops up more often than we think in, in in other fields and in with other diseases is this more common than than we realise? 


Chris van Tulleken  4:51   

We come up against you know, the technical stuff, is we suddenly find ourselves coming up against the political and the social and the cultural stuff more than in any other field. So yes, HIV is just one of the I mean, we've, we've then had SARS cov. Two, and even as SARS cov. Two cases are in COVID cases are increasing again, we have polio in our servers, and we have monkey pox cases, spreading in the community. So this is what makes infectious diseases medicine. so important and so interesting, it's that it's always changing. 


Rosie Anderson  5:27   

You've given some very recent examples there. And certainly, I feel as somebody who's just a layperson, that this is more, I feel like zoonosis or zoonosis. Is more on our radar than ever before. The phenomenon of species species transmission of disease, and everything that goes with it. But is that just a perception that it's becoming more common? Is this actually something which is increasing in frequency? Or is it just that we're more able to track it now? 


Chris van Tulleken  5:58   

I feel I'm not to be falsely modest. But I feel very self conscious answering this question in front of Kate. Because in all sincerity, it was Kate's paper, I mean, seminal paper that really awakened me to the idea that this wasn't just an observation bias, that this was really happening. And this is a thing that so Kate has a particular I guess, answer the thing that I see that Kate's forced me through her work to focus on is is asking that question, if there are these slightly glamorous diseases that make their way out of the natural world, the viruses that spread among wealthy people are the ones that get all the attention. But we're, of course, also seeing the emergence of antimicrobial resistance as a severe form of disease. And the fungal infections are really terrifying. And they are perhaps less linked to loss of biodiversity than they are to manmade climate change. 


Rosie Anderson  7:03   

Kate, what would be your response to that? That question? 


Kate Jones  7:08   

So I think it's really interesting Chris's perspective on that. But I would kind of highlight the conversations I have with Chris has also been really informative to me. So. And what I mean by that is that Chris is from another field, dealing with infectious diseases kind of at the interface, rather, rather than me just pontificating about it with a with a, with a model. A, he's actually, you know, dealing with that at the kind of clinical end. And I think there's a real distance between those two areas, which is incredibly interesting, and very unfortunate, at the same time, and it's one that we've got to bridge we've got to bridge it bridge in a better and more holistic way. So you have like the the kind of people who are dealing with the infectious diseases in the hospitals and the medics doing a fantastic job. And then you've got, you know, people like me, the ecologist epidemiologists who are dealing with the original reasons for why these things are happening in the first place. So you know, what, we're transforming landscapes, and we're changing climate, and we're changing the ecological systems that these diseases normally inhabit. So these pathogens are normally circulating in these ecosystems, and we're changing those ecosystems, and then they're jumping into into humans. And I think that medicine has kind of been a bit too siloed on dealing with the actual problem as in the person in front of you. And the ecologists have been too siloed in not speaking to those health professionals in a way that everybody can understand. So I think the ecologist have spoken to themselves. And I think that medics have spoken to themselves. And I think now we need a much better and more nuanced understanding of the whole system. 


Chris van Tulleken  9:18   

I just want to answer a different question. I think what Kate's saying so important because clinicians, infectious diseases, clinicians and microbiologists, I'm not sure we are approaching this problem yet, in the way we did smoking. So doctors were treating lung cancer and the respiratory doctors and the oncologists are when this is horrendous, we are going to put together evidence and we are going to be the ones who regulate the tobacco industry enforce that regulation. And they did it very, very successfully. It was an enormous battle. But I'm not sure that when we see the very, very real problems that Katie's studying in clinic and the effects they have, I'm not sure we are really located Seeing the problem out in the world. So for example, I now warn patients who are thinking of getting pregnant, you know of childbearing age and may become pregnant when they when they travelled to the south of France, that we now have Zika virus, which can cause birth defects. And it's very rare, but there has been transmission now in the south of France. So that is we're seeing climate change, moving those mosquito vectors further north transmitting a virus that can cause really serious effects into Europe. And we don't really link that to climate change. I don't think in that conversation, we haven't become activists enough about it yet. I mean, case, is that your is that your perception? 


Kate Jones  10:47   

I do think there are increasing calls for for, you know, a more synergistic systems based approach to thinking about infectious diseases. And I think that's really welcomed. But if I just give you an example of how siloed it is at the moment, so there's all this talk about one health. So one health was kind of born from medics and vets getting together and going, oh, gosh, you know, we've got animals sick and people sick. And that kind of interface is really interesting and really needs work. And then we've got planetary health, which is kind of medics thinking and public health people thinking, Gosh, climate change is a real big problem. And you know, there's also problems with infectious diseases and mental health, you know, we need to think about this in a more sustainable way. And then we've got eco health, which is the ecologist saying, Gosh, should we should actually be working together with with vets and medics, so you can see by those three terms, which effectively mean the same thing, but it just depends on which, which part of that kind of part of that world you come from, is what you call it. And that's a real problem. I think that's a real problem. And I think we're still a bit siloed we can't even decide on on an actual name to call this, you know, 


Rosie Anderson  12:17   

yeah, no, I, I'm fascinated by this as well, myself, I have an academic interest in this myself too, or research interest in this, I'd love to come back to it in a minute. But I just want to make sure that we've covered exactly what we're talking about when we talk about zoonosis. itself. I think a lot of people who come to this fresh will think well, how on earth does that contribute to disease in humans, that's quite a quite a long way away from most people's experience of health. So could you both explain to me, however, works, it works in your particular practice in your work, 


Kate Jones  12:54   

I kind of view it as it's not, it's not kind of biodiversity loss, per se, that's important, actually, it's more like you, you have this, these ecosystems. And ecosystems are made up of animals in their animals and plants and microbes in their environment. So you have these kind of ecosystems, which are working fine. So say, a forest or bottom of a lake or whatever. And then you've got some kind of disruptive force. So say it's climate change, that you've changed their kind of tolerable temperature or rainfall limits for those some of those species in that system. So they have to move, they die, or they move, or you've you've cut down the forest. And so you've changed the ecosystem now into something else. So some species won't be able to survive in those environments. So you've now got, you haven't got, you may not have biodiversity loss, per se, but you've got to change in that ecosystem. And the species which tend to survive in those degraded ecosystems, or they can easily move into another area are things which kind of live fast and die young, and they typically invest less in in immunity and immune systems, then species which are long lived and you know, survive and reproduce quite slowly. And so it tends to be those species which were they're left with in these degraded environments, or changed environments. And it's those species which tend to seem to, were more susceptible for species for microbes to jump into, into humans. So every species on the planet, including us, has a huge variety of pathogens, so everything that's just normal, and it's just when you change those transmission dynamics between animals and people that you have these jumps. So that's when these jumps happen into human populations, but we are changing the ecosystems into some thing that's more unhealthy and has a higher probability of of a microbe jumping into it into a human. So it's about the ecology and the ecological interactions between species, which is, that's the cause of it. That's the foundation. And then it's how land use and climate change are changing those interactions. And of course, that's just one part of this system. The other bits of it are, you know, the exposure of the human So what other human behaviours which mean that you're more or less exposed to these, this kind of zoonotic hazard, this animal hazard? What's your susceptibility? So if it happened in a really rich country, which could put afford to put loads of money into health care centres or vaccinations, then you wouldn't, you know, it would this pathogen would leak into the human population, but it wouldn't be a problem because it'd be controlled. 


Rosie Anderson  16:01   

Chris, I, I can't help but wonder listening to how Kate explained that, because it seems so obvious to when, when Kate explains what this is. What is it? Do you think that means that it hasn't been a bigger feature of our discussion about health and about where disease comes from and, and how it gets transmitted and moves through populations? In certainly in medical circles, but but definitely public discussion around this as well? Is it just we didn't know? Or is there other other factors there? 


Chris van Tulleken  16:33   

That's such a lovely question. I think when Kate explained what she just explained to both of us when she first explained that to me, I had a very simple model that if you cut down a forest, the displace the bat is more likely to go and to live in someone's house or farm and, and you're then exposed to the bat. And case description of these degraded ecosystems with immune vulnerable animals that are then viruses behave very differently when animals are immunosuppressed. And I think it's had such an impact on my life, every time I see an urban Fox. And I think urban foxes where I live in Hackney are in a particularly sorry, condition, I always think of how they are living in this sort of marginal landscape that they're not really evolved to. And they're really ill. And I don't think there is any Fox related illness, but it's changed, it's just tweaked my understanding of my own local area, I think there is also a parallel, where we've seen with immune suppressed humans living in degraded land state escapes, which is probably almost most people on Earth, suffer with malnutrition of one form or another, and chronic infectious disease of another kind. And we've seen this in the in the COVID pandemic, there is a, it's hard to be exactly certain. But we think that the population of HIV patients living in Southern Africa who are badly treated, because they don't have access to the drugs that are there, right, and which they should and could have access to. We think that they serve as a reservoir for development of new of a very high rate of new mutations. And so the humans as well exist in these degraded landscapes. Why we don't think of it, it may just be that what Kate is describing is fabulously complex. And it's overwhelming in clinics, when you are simply trying to deal with the human in front of you to start trying to solve or even engage with problems that feel so deeply enmeshed in our world economy in our world political system, that I think a lot of clinicians just become a bit overwhelmed. So we think of HIV as a human disease. No one thinks of HIV as a zoonosis, for example, it's a disease that spread between humans, but it was a zoonosis, you know, probably first around 100 years ago, 


Kate Jones  19:02   

I guess also, that's a problem with development money as well, like so it's kind of treating the child and bednets to stop them getting malaria. But what about understanding the whole ecosystem and how degraded it is? And where is the money that goes into making sure that not just the child's health is increased, but the child where the child lives, is not a degraded landscape, it's not polluted. And I think that kind of link between just treating the patient with that symptom and treating the patient within its environment is is not it's not quite there, although I think it is getting much better. 


Rosie Anderson  19:46   

Yeah, I was really struck when Chris you were talking earlier about how so much of how this how how this works, the determinants behind these zoonosis And while everything we're talking about is linked in with our lifestyles and our culture. And once you start getting into that stuff and put that stuff in play, it starts to get really complex, doesn't it? It's about it's about very complex systems and interdependencies and stuff. And my own background is public health policy actually. So I do, I look at the politics of health, and how we even can talk about health amongst ourselves. 


Chris van Tulleken  20:23   

The whole conversation around infectious diseases of all kinds is suppurating with stigma. And there is almost no way of describing those at risk of particular infectious disease without stigmatising them, and without suddenly getting into politics. And then we have, of course, the politics of vaccination and disease prevention. And I think that all intermingles with this idea that there's there's no money in pandemic prevention. And so I think we have to ask, what would be the incentive for those people? And for many governments to actually prevent pandemic, there is a moral incentive that I think most of us feel. But I'm not sure that the incentives at the moment are very aligned. I think we're still not seeing anywhere near the investment. That is that would match what the pandemics cost us in terms of human life and the effects on the economy. 


Rosie Anderson  21:24   

Yeah, actually, I'd love to talk a bit about that. To think about what you mentioned before Kate, about one health approaches, and you explain them in this in the context of you know, all these different disciplines kept trying to come together. What are one health approaches when it comes to making policy around? Yeah, prevention of pandemics, for example. 


Kate Jones  21:48   

Yeah, I think there's a nice example with with a disease in West Africa, where the snails have the disease, and they pass them on to humans. But if you have a more healthier ecosystem in those in those water bodies, it's a more balanced system, so that, you know, you have the prey base and the prey and the predators and you get less transmission of that disease into human populations. So that is a an example where you can have watershed rewilding. And it also then means that you have less of a problem with transmission of infectious diseases. And those are really difficult, difficult problems, you know, so how can you have still have food security, but still have wild areas for those species? So I think that's something to think about. But yeah, it is a problem. It is, it is a tricky problem, but you're not going to solve so notic transmission without thinking about it in that way. 


Chris van Tulleken  22:54   

Do you think that a lot of this stuff runs against our historical experience in terms of like, the way we've dealt with disease and pests is just to try and kill them. And that's, that feels logical if you if you have a vector of a disease, you spray everything with DDT, you you try and kill the vector or the reservoir, and that feels like it would work. And then we have all these very peculiar examples, the one you've described, and then that those think the rabies one is the most surprising that the huge campaigns in Southeast Asia to kill unvaccinated dogs, that enormously increased transmission of rabies, because what you really want to do is to have a very large number of vaccinated dogs acting as sort of soldiers in the fight stopping transmission from the small number of rabid dogs. And so I think unless you're a quite an instinctive, intuitive, expert mathematician, almost I think what Kate does is very mathematical. Your instinct takes you away from solutions and you end up applying pesticides, setting traps, killing things, destroying landscapes further, and not understanding why it isn't working. 


Kate Jones  24:12   

I think it's a really interesting point, it reminds me of, you know, the way that we farm food and had farm food before World War Two. And we had a rotational crop system that wasn't as efficient and didn't produce all the food that that was needed at that price that was needed. But and so that cuts down on pests that cuts down on degradation of soil that increases the microbial content of the soil and the right sorry, Racket, my ribosomal networks, 


Chris van Tulleken  24:45   

so we're so pleased you struggled with that.  


Kate Jones  24:50   

We had a system pre World War Two in this country, which was sustainable and to increase The production, we started putting on changing that entire system and using some of the replacing some of the natural processes like rotational crops with pesticide. And now we've got a destroyed landscape and destroyed soil, degraded soil. And it's becoming more and more apparent that that isn't sustainable, that isn't sustainable on many levels. And so I think the the kind of point I'm trying to get to is that we have put some quick fixes in, because we have the technology to do so. But not the understanding of the system. So it does, it does seem to make sense to get rid of malaria and mosquitoes by pouring DDT onto them and reducing that kind of transmission cycle. But then that has massive implications for all of the other life on the planet, it's especially some of the birds, you know, that led to the environmental movement of Rachel Carson, Rachel Carson, talking about the Silent Spring where all the bird populations have gone, if you decrease the bird populations, who's going to eat all the insects, so you have to put more pesticides, and then you've got runoff into the streams, you've got nitrification of the landscapes, you know, all of this is, is kind of not being costed in. When we talk about our ecosystems and our economy, we're kind of it's kind of out of balance, and it's not sustainable. So I guess it's, we need to move away from these quick fix these quick technological fixes, and a better understanding of how we manage our landscape in a much more sustainable way. 


Rosie Anderson  26:50   

So Kate, now would be a great time, I think, to explain in a bit more detail exactly how your research is contributing to that. 


Kate Jones  27:00   

So I kind of started off a number of years ago, when we started thinking about taking a more kind of quantified spatial look at where diseases emerge where these zoonotic diseases emerge. And so we we got together with a number of colleagues in the States. And we tried to map out the first time that an infectious disease has emerged into the human population. So we looked at vector borne diseases, which are, you know, like malaria, dengue, or Zika viruses. And we also looked at zoonotic diseases. So we kind of looked at when those first occurred. So this is the first time that anybody had kind of map that out, but then thought about what the drivers were for this emergence. And so we came up with this, the first kind of hotspot map of where the biggest drivers were. And that was explaining some of these hotspots of emergence. So that was showing that areas where human population was the fastest growing, where biodiversity was the highest in terms of you know, there was an interaction between biodiversity loss and human populations increasing, they were the areas where we we'd seen in the past these infectious diseases, emerging zoonotic diseases emerging. And so that kind of hotspot map was really influential in setting the agenda that there was, there was an environmental driver here, which we could start to understand and make predictions about, where where the the risky spots were in the future. And so these maps were taken up by a USA ID, and they put huge amounts of money into understanding of setting up new labs in these areas to start looking for new viruses and new pathogens. 


Rosie Anderson  29:09   

Chris, as from an infectious diseases, medical point of view, why was it so important to be able to draw that map? Well, I 


Chris van Tulleken  29:21   

think there's there's the kind of theoretical answer, which is it allows us to make predictions and do public health and allocate spending and understand the impact in theory, and then there's the sort of actual answer, which is that it it has not had nearly the impact that it should have. If that. Does that make sense? That doesn't sound like I'm doing down case research. It's just this should this should have transformed the way we think about ourselves about medicine about the planet. We should have surveillance centres all over the place. We should be spending trillions of dollars on this a year. And that has not happened. And the reason it isn't, I think is not through inertia. It's not through lack of political will. It's because that we externalise all the costs to the planet, and we privatise all the profits. And this has been the case since Rachel Carson wrote her book Silent Spring, that there is simply no reason if you are a company, polluting a river or making making profit from things that increase the risk of pandemic disease and harm the planet and humans in all kinds of other ways that you don't pay the cleanup cost for anything, the literal cleanup cost of the swamp, or the water supply, or the sort of metaphorical cleanup, cost of, of the disease, all those things are just picked up by the public purse. And until we start to take those external costs and force the companies that create them to pay for them, I think nothing will change. So it's it's extremely profitable to spray crops with pesticides for everyone involved in that system. And I love that point about World War Two in food supply, because a lot of my work now is about conflicts of interest and how money distorts agendas, particularly within medicine, particularly within the pharmaceutical industry, but also within the food industry. But as a scientist, as a clinician, it's very clear that industrial interest drives a lot of this problem, the ecosystems are degraded, because the it's useful to grow oil palm on tropical forest. And until the oil palm companies are made to pay for the pandemics that they cause, whether it is pandemic obesity, pandemic malnutrition, or pandemic disease, they will continue to cut down forest, you know, 


Kate Jones  31:55   

the, the the research, not not just kind of highlighted where things were likely to emerge. But I think one of the things that it did really well was make that link to biodiversity, you know, and make that that, that argument about degradation of ecosystems. And I think for many years, the kind of arguments where biodiversity loss equals pandemics, which is not strictly true. But those arguments were actually quite useful in starting to change that narrative, you know, changing that narrative between, you know, ecosystem structures really important into preventing pandemic emergency. And I think that was kind of growing in momentum. And then I think, the COVID 19 pandemic really spurred that on, I think there was a lot of stuff going on, and the herd, if you like, for a number of years, and then with a pandemic mind, the COVID 19 pandemic, I think that really did bring that out in a really spectacular way. Where that where ecosystems are really important, it fitted a narrative of nature based solutions for climate change, you know, turning thinking about how we use forests, how we use wetland to mitigate and adapt to some of the climate change impacts, how we do sustainable farming and food and, and kind of Brexit showed us the kind of fragility of some of those international trade routes, you know, so it all kind of came together. And then I think there was a real shift in understanding that ecosystems are important. And I think that I saw that in real time happening. I think that's, that was really exciting. But I think we hadn't had that kind of groundswell of of, of, of evidence, that wouldn't have happened, but I think that's what happened. I saw it happen in COVID-19, which was, you know, in some ways, horrifying, but also amazing that we saw the World Health Organisation, unit, you know, the UN WWF you know, all of these big organisations going, oh, yeah, there's, there's a link, we need to see another reason why we need in tax ecosystem. 


Chris van Tulleken  34:33   

My kit, the difference between I think, Kate night is the case is somewhat optimistic, and I'm pretty pessimistic. And maybe I think this comes from studying conflicts of interest. And what I can't understand is why Kate's research haven't come out along with all the other research in this area. Why do we still have ongoing transmission of HIV? Why are we still cutting down hardwood in tropical forests? Why are we still begging for oil. I mean, you know, but I think Kate's perspective is much more useful one that of course, we have seen change, and we must keep, keep pushing for more change. But I, I, I would like to see much faster change, but much bigger change much, much faster. I think that's what Kate's research deserves as his outcome. 


Kate Jones  35:19   

I don't know, I've just been at it for a long time in terms of thinking about how to change people's minds, the kind of background I'm coming from was, you know, 20 years ago, realising that we were in a kind of biodiversity crisis, a climate crisis, and nobody, nobody cared. And I've seen it come 360 And that gives me a reason to get up in the morning because I've seen you know, young people being so engaged in climate change and wanting something to change and sanction rebellion with biodiversity loss, and, and people understanding how ecology and, you know, ecology, I just mean, the animals and plants and microbes and everything that makes up the world and their interactions with humans in the middle, or at the side, or whatever. This is where we are, we're put we're part of that system. And that system is incredibly important. It's our life support system. And I think I've seen people's attitudes change to that. And every day, you know, on the radio in the news, there's always something about climate change or food security in ecology and biodiversity and, and that's what keeps me going. 


Rosie Anderson  36:38   

That's all for now. I hope to see you next time when I'll be talking to Professor Alan Smith about how his optical sensors are helping space agencies search for planets in the depths of the Dark Universe. If you can't wait until then, and want to hear more about how UCL research is transforming society in the world, then why not take a listen to me at UCL presented and produced by our students. Finally, I'd like to thank our guests Professor Kate Jones, and Dr. Chris Van Milliken, and of course you our listeners 


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