Predicting and Preventing the Next Pandemic
November 3, 2021
Sabrina Sholts:
I am Sabrina Sholts, I am a biologic anthropologist, curator of biologic anthropology, from the National Museum of Natural History at the Smithsonian and I am the curator of our outbreak exhibit. I am a blonde-haired woman wearing a white shirt and a tan jacket and I'm seen from a background which is my office at the museum actually and then on the screen that you can see, a photo here of our featured speaker today, Jon Epstein with a bat. You'll also see that we've got our title here for our program, Predicting and Preventing the Next Pandemic, and thank you all for joining us.
So as people continue to trickle in, I'm going to get through some standard housekeeping issues and notes for those who are new to our programs. So first, closed captions are available by clicking the arrow next to the CC button on the Zoom toolbar. You should be able to see that or that's located at the top or the bottom of your screen. We are going to be opening up for audience Q&A after our conversation but please feel free to submit your questions at any time in the Q&A box on the Zoom toolbar, and that Q&A session goes by really quickly, so please do help us out in answering as many questions as possible by submitting your questions as you have them and we would love to know what you want to know.
Okay, fantastic. So you know what? Let's get started. Today's program is pretty special for a couple of reasons. We have been doing programs in association with the outbreak exhibit since before it even opened in 2018, and the exhibit itself emerged, you could say, in the wake of the 2014 epidemic in West Africa, actually from an idea by someone who was on the front lines, an infectious disease physician named Dan Lucey. We all agreed, we all believed that it was critically important for the public to know more about emerging infectious diseases, novel zoonotic viruses, and pandemic risks in the 21st century because as we knew then and I think everyone sees now, these are some of the greatest threats that we face in our highly connected world.
Interconnectedness is at the core of the outbreak exhibit and our main message is that human, animal and environmental health are all connected. That they should be considered and seen and treated as really one health. So that's why it's such a treat to be doing this program today, which is One Health Day, a day that recognizes the importance of one health, and all the work that supports and applies it.
Working together is actually the secondary message of the outbreak exhibit, which would not have been possible [inaudible 00:03:18] many experts with whom we worked to develop the content over a number of years. Our program today features one of those experts, our chief science advisor for the exhibit, Dr. Jonathan Epstein, which is another reason why this program is so special. So with that, I would like to introduce our speaker for today's program, Jonathan Epstein. Jon is the vice president of science and outreach at EcoHealth Alliance in New York City, a science-based NGO. He is a veterinarian and an epidemiologist and his research focuses on the ecology of zoonotic viruses that impact animals and people, particularly that are associated with bats, such as the Nipah virus, Ebola, and emerging coronaviruses, such as SARS-CoV, MERS-CoV, and SARS-CoV-2.
In 2004, Jon was part of the team that discovered that bats were the reservoir for the SARS virus in China and in 2012, he and his colleagues first identified MERS-CoV in bats and camels in Saudi Arabia. He has served as the technical consultant for WHO, OIE, FAO, National Academy of Medicines, [inaudible 00:04:43] Microbial Fats and again a science advisor for the outbreak exhibit at the Smithsonian's National Museum of Natural History. He holds adjunct appointments at Tufts University, Columbia University, and Mount Sinai School of Medicine. So Jon, welcome, and thank you so much for being here.
Jonathan Epstein:
Thank you very much Sabrina. It's great to be here.
Sabrina Sholts:
It is great to see you. It is great to see you and thank you so much. Happy One Health Day.
Jonathan Epstein:
Happy One Health.
Sabrina Sholts:
Yes. Which is ... I mean every day for you is One Health Day, right? I was thinking, going through all of your credentials and your background, I mean it is just fascinating to think about and get some sense of all that you do and have done and wonder actually how you got to where you are. I was wondering if you could actually first talk a little bit more about what you do at EcoHealth Alliance and please tell us how you decided to follow this path in the sense of what were your goals and interests and what were decisions that you made along the way?
Jonathan Epstein:
No that's great, and I just want to thank you for putting this on and inviting me here today and One Health Day is a great opportunity to talk about the issues that are core to the exhibit and that are obviously very relevant today when we're living through a pandemic that is caused by a virus that originates in animals and I got my start, as you mentioned in the intro, I'm a veterinarian by training and an infectious disease epidemiologist, and I got into veterinary medicine really out of a love for wildlife. I wanted to become a vet to work in conservation and protect biodiversity, and fortunately really stumbled into public health as a parallel study that I was doing.
I went to vet school and did my public health degree up at Tufts University in Massachusetts and I did them concurrently, and in doing that, it really got me to think about linkages between human and animal health, and infectious disease became a very obvious and the more I studied it a very natural avenue for thinking about how animal health influences human health and vice versa, and it was at a time when the field of what we talk about as one health, then conservation medicine which is really synonymous, was the idea that health issues are complex and nothing should be studied in a vacuum and nothing exists in a vacuum and we are very linked to nature in a lot of ways and so is our health. And so I was really lucky to be able to do my training at a time when I could apply these concepts and notions to thinking about how wildlife impacted human health but also how human impacts on the environment impacted human health and led to disease emergence.
So my career arc has really been to look at how viruses that ultimately become outbreaks in human populations start in animal populations, typically wildlife populations, and why do they emerge? What makes those viruses leave their normal animal hosts and get into domestic animals or people and ultimately cause outbreaks and in some cases pandemics. So that's been really the focus of my research over the last 20 years, and it's very much at the center of what we do at EcoHealth Alliance and so I can tell you a little bit about what EcoHealth Alliance does as an organization. We're a science-based non-profit up in New York City and we work globally.
Very much with local partners, scientific institutions, government agencies, other non-profits around the world, where diseases tend to begin, where they emerge, where they exist in wildlife reservoirs, and we ask questions about how do they operate in nature. So for example if it's a virus, like a coronavirus, what animals tend to carry it and what are the circumstances by which it is able to get out of the animals that normally carry it and into people, and I'll tell you that over the past 15 years, the field of this science has really amassed a significant amount of evidence to show that the single biggest cause of pandemics are people. Things we do to the environment, changes we make environmentally that influence the way we contact wildlife and interact with nature. Such that there's more and more opportunity for viruses like coronaviruses or others to get from their natural animal hosts either into domestic animals or directly into people. So our mission, our organizational aim is to not only understand how viruses emerge and become pandemics, but really work with local partners, governments and policymakers to make changes on the ground to reduce the likelihood of that happening.
Sabrina Sholts:
Yeah. I mean it's fascinating Jon to see this map, and I have no doubt that so many people and so much effort and cost [inaudible 00:09:34], and just so we can all interpret this correctly, so the brightest places on this map are those that are most likely or have been predicted to possibly be the sites of newly emerging infectious diseases, is that right?
Jonathan Epstein:
Yeah. And maybe just to put this into context a little bit, where the science has gone over the past 20 years in terms of our understanding why epidemics and pandemics happen, particularly of zoonotic diseases, those that transmit or originate in animals and make their way into people. We've developed a really good understanding of how they happen, in other words, the things that we're doing that influence diseases being able to emerge, but also where they're most likely to happen and this map is the product of years of research that we did, looking at 90 years of historical data of all emerging disease events. So everywhere on the planet where we first saw a new disease emerge, and particularly if it was zoonotic, if it started in wildlife or started in animals and got into people, kind of mark that instance, and then projecting forward, using all of that information to say based on past history, where are we pretty confident that we're most likely to see more and more of these diseases emerge, based on factors like biodiversity.
So the variety of wildlife species that occur in a single area. Human demography, what's the human population like in terms of density, and what are the dynamic processes, like land use change, which we now recognize as the single most important driver or influencer of disease emergence. That's deforestation, forest fragmentation, conversion of landscapes from say forests to agricultural, or agricultural to urban. It's that process of changing the environment around us that changes the types of animals that might be found in that environment and the way and frequency which people come into contact with those animals.
So this hotspots map really reflects a predictive and statistical analysis looking forward as to which parts of the world are really most vulnerable to diseases emerging, and that's important because it allows us then to take what are very limited resources globally and focus them in parts of the world where we think they'll have the highest impact.
Sabrina Sholts:
Yeah. I mean it seems like a very powerful tool, right? And a very concerning one. I mean it looks like John, you are in a hotspot now. That's New York City [inaudible 00:12:04].
Jonathan Epstein:
No. Not New York City behind me, I wish it was New York City, but this is actually a scene from Malaysia behind me. We do a lot of work in Malaysia, but in Southeast Asia ... Is that what you're asking or you're pointing to New York on the map?
Sabrina Sholts:
No, I'm looking at the hotspots map. I'm looking at the hotspots map and I'm looking at New York City here.
Jonathan Epstein:
Well I was going to say that to start with, Southeast Asia is a hotspot because it's undergoing a tremendous amount of environmental pressure with land conversion and deforestation, so that's what's behind me. New York is shown as a hotspot and the reason that there are hotspots, you might not think of the United States or Europe or parts of Asia that are more industrialized as being hotspots, but included in the risk of emergence are things like global travel and trade, so we've had diseases emerge in the United States, specifically in New York. You may recall West Nile virus back in 1999 which first occurred in New York, and then spread across the country and this was introduced via travel, probably the importation of an infected bird or infectious mosquitoes that made their way into airport areas in New York and then infected people and birds locally, and then that disease established itself in the United States. So we do have diseases that have emerged in Western countries, but you can also notice that primarily, we see a lot of areas in the tropics where there tends to be high biodiversity as areas that we're paying particular attention to.
Sabrina Sholts:
Well yeah, and that's a good point, and you mentioned this, that you're working globally, you're working locally globally, right? And so it seems to me that you'll put a map like this together and you'll look at where you really need to have data and be able to identify these target areas. You're working in a very I guess international space, with a lot of interdisciplinary collaboration. You mentioned human factors and as an anthropologists my ears peak up when I hear about social science potentially. Is there anything you want to say about how that work happens? Who are the other people that you're working with that maybe have expertise different from yours? And who are playing important roles [inaudible 00:14:13]?
Jonathan Epstein:
Absolutely. It's a really important point, and you know this very well from conversations we've had, that anthropology and social sciences are central and critical to actually changing human behaviors on the ground, to influence and decrease risk for disease emergence but I think what's important to understand is science has changed dramatically over the past few decades and gone are the days of the lone scientist sitting over a microscope alone, doing research and looking at those findings. But to really address big, complex scientific challenges, things like climate change or disease emergence, these systems are so complex it just requires expertise from a whole spectrum of different scientific disciplines, and so we talk a lot about or you might hear a lot about epidemiology which is important because that's the study of diseases as they affect populations, but for really understanding disease ecology or understanding pandemics, you need to bring together people from animal sciences, veterinarians from the health sciences, ecologists who understand population dynamics and environmental influences on wild animal populations, but also human health specialists. Physicians, epidemiologists, laboratorians and basic scientists and very importantly, social scientists, anthropologists, sociologists because what's really important to realize is we can't reduce risk of pandemics happening, sitting in an office or a lab in New York or Washington, in the United States.
We have to partner and work with local experts in the parts of the world where diseases emerge because they have the best understanding of cultural norms locally and behaviors and policies that really affect the way that people interact with animals and their environment, and so everything we do at EcoHealth Alliance is with local partners internationally. We're working with local scientists, local social scientists, local policymakers because they're the ones who have the best ability to understand the context of the science we're doing. So it's multidisciplinary, but importantly, it's multi-geographical, and it really involves global partnerships to have any impact at all in doing this work.
Sabrina Sholts:
Yeah. Yeah, and it's really incredible to think that all these people who are involved in making a map like the one that we were looking at, you said that that's based on decades and decades of data, and so there are so many people who have been out around the world, working and knowing. Probably most likely we were facing risks for another pandemic sooner or later and I'm curious, for you was it surprising when a new coronavirus emerged in late 2019. Honestly, why or why not?
Jonathan Epstein:
I think that just by the very fact that we stood up this exhibit on outbreaks to talk about how likely it is that we will see more of them and how important it is to communicate why they happen, that we did understand and believe all along that these things are happening with increasing frequency. So historically, we are seeing more and more emerging diseases, more and more outbreaks of zoonotic disease because of the influence that our growing human population is having on the natural world around us. It's based on a ton of evidence and what you're showing now here is really a historical map. This is almost the underlying basis for a lot of the hotspots analysis are historical outbreaks and this is a map that I've seen, this is ... Tony Fauci created this and he adds dots to the map almost every year as there are new outbreaks recognized, and will continue to do that.
But what I really want people to understand is that we don't have to feel like we're helpless victims when it comes to pandemics. It's scary, it's confusing, there's struggles right now to understand how we're in the midst of the pandemic we're in now, but at the same time, we know enough to understand what we have to do to reduce the likelihood of these happening again. So while on the one hand no it wasn't a surprise that we were going to eventually see something like this and I've been working and my colleagues at EcoHealth Alliance have been studying coronaviruses continuously since SARS, so for the past 15 years, and we're doing research and finding evidence to suggest that not only was this probably going to happen but that there was evidence that people in rural communities were being exposed to coronaviruses like SARS. So it was just a matter of time, but there are things we can do and importantly we understand what the major causes are for pandemics. Land use change, agricultural intensification, livestock development without biosecurity, meaning that as there's a growing demand for livestock and farms are getting bigger and more intensive, we have to pay attention to making sure there are barriers in place so that those livestock don't come into contact with wildlife and so that disease emergence can't happen on farms which has happened in the past. So that's an important driver and that's controlled by us.
Thirdly, wildlife trade. Taking wild animals out of their natural environment and bring them into a market system where they might end up in urban areas, in towns or cities where they're sold for food or for pets. This also creates risk when we bring lots of different animals together in very stressful and unhygienic conditions which is often the case through the wildlife trade. That can really create risk at every point in that chain, from catching the wildlife in the wild to transporting it to its ultimate location to mixing it with other species in a market system. All of these things have been connected to disease emergence and create risk.
So we understand the major activities that we need to rethink and change and in some cases stop to reduce risk and we also need to focus on understanding at a local level where spillover is likely to happen, and start putting policies in place, interventions that are going to reduce that risk of it happening.
Sabrina Sholts:
I think that's a really important message Jon, what you're saying, it's very positive in a way. I mean it's hopeful, it's empowering to be able to think of ... To be able to frame these pathogenic [inaudible 00:20:47] with the activities and behaviors that are within our control. So you've I think laid out really nicely what we can do I think, what we should be doing. Is there anything that you would say we're not doing right now or that we specifically and very strongly need to do more or better?
Jonathan Epstein:
Yeah, and unfortunately, I and others have given this a lot of thought and I think it's human nature that we're almost predisposed to putting out fires. We respond to crises, that's what tends to kick us into action, and too often, we respond to crises by throwing money at things like more laboratories, drugs and vaccines. Things that will detect outbreaks, things that will treat diseases once they exist. Now those are really important tools in the whole toolbox in terms of dealing with epidemics, but what we do too little of, and where we really need to start investing resources, money and effort, is in preventing spillover.
Going all the way upstream to that very first point of contact where an animal virus makes the jump from the wildlife that carries it into the group of people or individuals who have contact with that wildlife, and if we can do more to prevent those events from happening, it will obviate the need, it will reduce the need to be able to respond to these outbreaks and try to contain them and I think what we see time and time again is by the time we're actually aware of an outbreak in the human population, it's almost too late, because it's so easy to travel and because people move around so freely around the world, things spread very quickly, and by the time we're aware of it, it's already too late and we saw that in this pandemic where we're starting to realize retrospectively there were probably cases in the United States way earlier than we thought, early in 2020, perhaps even late 2019, when we didn't even think it was going to be an issue until February. So we were reacting too late.
So a lot of these strategies we have right now are reactive to outbreaks and what I think we need to do is focus on being preventative and really going upstream. But the challenge we have is that we're ... With prevention, and this is a challenge that any preventative field has is that if we're doing our job right, nothing happens, and it's very hard to demonstrate pandemics avoided or outbreaks averted and so it's much easier to say, "Hey, look how many vaccines and drugs we developed. Look how many labs we're building to help us detect these things faster." And again, important and useful, but not the answer for preventing pandemics.
Sabrina Sholts:
Yeah. So I wonder, I mean with all that you do, everything on your plate, you've found the time and had the interest to work on an exhibit with us, a museum exhibit. To my knowledge, you had not done this before. It was a huge time commitment. We really, really relied on your expertise. Was that part of your thinking about how [inaudible 00:23:51] preventative and the things that we can do and how we can use knowledge to better prepare ourselves? I guess I'm wondering if you want to talk a bit more about your involvement in the exhibit, how that was for you and what you think the outcomes were.
Jonathan Epstein:
Yeah. Well I mean first of all, I couldn't be more grateful and appreciative to be involved in an exhibit like this. And again, worth acknowledging Dan Lucey, really whose brainchild this was, but to be brought into the team and to help create this was a dream because I think science and maybe never more so than now but science is challenged and that there seems to be a lot of barriers between scientists and the research we do and the public and their understanding of what that means to them and in their lives. That's a communication issue and there is a lot of struggle to communicate why science matters to people in their everyday lives.
So a lot of what I do is communication and outreach as part of my job and I really am passionate about making sure that the science that is happening around health and one health is understandable to people. So this exhibit is, I mean I couldn't think of a better way to reach more people than a physical and immersive exhibit at one of the most visited museums in the world. This is from all strata of the public, all members of the public who can come through here freely to see this. So it was a tremendous opportunity and I think that certainly before the pandemic, one health or epidemiology or public health was really not in the conversation and I don't think people really thought about how our health is connected to that of animals and the environment, because while we talk a lot about diseases that start in animals and get into people, it really sounds almost menacing. "Oh, we're getting pelted with all these animal viruses." But it really is a circular connection in that we are influencing that pelting. We are the ones who are really creating these circumstances by which we're getting exposed to a lot of these viruses.
So one it's hopeful because we can change that, and change how this happens, but two, importantly, the answer is never to further divorce ourselves from nature. I mean that is something that has happened over time I think with people in many societies and certainly not in many parts of the world but talk about here in the U.S., we kind of get separated from nature and forget how important biodiversity and wildlife are to our well-being. So there's a real positive force that animals and natural environments have on us in lots of ways, and one of the negative consequences of us disrupting natural ecosystems are outbreaks and things that impact our health negatively.
Sabrina Sholts:
Well yeah, and to your point about people not thinking about wildlife, [inaudible 00:26:38] in this country, maybe not [inaudible 00:26:40] connected to it, and then the ways the Smithsonian has maybe highlighted some of those issues, intersections. I want to ask you actually about your thoughts on recent happenings at the Smithsonian during this pandemic, where some of the big cats at our zoo tested positive for COVID-19, and I think that that probably got a lot of attention, that's something that people can relate to. I think that very nicely illustrates spillover and I don't know if you call that a spill back, I mean that's certainly a zoonotic transmission, but I guess ... There must be so many more examples where pathogens have spilled over from humans to animals under our care and around us. I was wondering if you could tell us a little more about that.
Jonathan Epstein:
Yeah. It's a really important concept. We're very human-centric in the way we think. We're selfish as a species here but a lot of diseases that impact people have significant health consequences if they get into animals, and we don't talk about that as much or see it as much but I'll give you an example. Measles, measles virus which is highly transmissible and it's something that we largely control with vaccines, but we do have measles cases around the world. When that gets into great apes, gorillas and chimpanzees, it can be a fatal disease. So that's a human virus that when it gets into animals can have fatal consequences.
We also know that there are viruses out there that are already capable, genetically capable of infecting lots of different species, and I think SARS-CoV-2 is a good example of that where this is a virus that originates in bats and there's a lot of evidence to really suggest that that's the case, but it has shown that it is able to not only infect people, but infect lots of different animals including cats. Mink, we've seen evidence of COVID getting on mink farms where there's a high density of mink. The virus has circulated and one of the important things that can happen when a virus jumps back into animals from people is it gives it further opportunity to evolve. Viruses change when they jump into new hosts, and particularly new host species. So we've talked a lot about variants of COVID that have come up just by virtue of it circulating in so many people around the world, but we've also seen variants arise when the virus has jumped back into animals and that's what happened when it spread through mink farms in the United States and in Europe.
So we've seen some zoo animals get infected and fortunately not suffered too severe disease, but it was noticeable that big cats in several different zoos did get infected. So when so many people around the world are infected with COVID, it creates a really unique and unprecedented point in history where there's lots of opportunity for animals to get exposed to people who are sick, and so that's something we need to pay careful attention to because there might be opportunities for this virus to establish itself in other wildlife species naturally and start to circulate.
Sabrina Sholts:
Yeah. So are you saying, I understand that when an animal gets sick, even if not severely ill as we can do from COVID, that's not a reservoir. A reservoir host, [inaudible 00:29:59] is an organism that can carry that virus without symptoms of illness, correct?
Jonathan Epstein:
That's right. You think of a reservoir species is like a reservoir of water. It's a species that normally carries that virus, the virus can maintain itself within that species kind of indefinitely, that has what it needs. And then other animals that get infected or people we refer to as other hosts that can be infected.
Sabrina Sholts:
Yeah. So are you suggesting that we could be creating additional reservoirs for a virus like SARS-CoV-2? Would that then allow the virus to possibly re-emerge?
Jonathan Epstein:
Well that's certainly possible, and it's something that we're paying very close attention to. Now so far there is no evidence that COVID is circulating in wildlife populations on its own other than the bats it came from but it's something we do need to pay careful attention to and there have been studies to look at say bats in North America to see if they're likely to become reservoirs, it looks like that risk is very low. We're also paying attention to animals related to mink, like weasels or martins, other mustelids that are native to North America and the United States where they could become infected and could this circulate amongst them. So no evidence yet that it's established itself in other species, but we do have evidence of it jumping in other species and causing individual infections.
Sabrina Sholts:
That also suggests, I guess it's always in the case of a zoonotic pathogen or virus that you can't eliminate it if it has hosts beyond the human species, right? Because we certainly can't eliminate those hosts and therefore it is with us.
Jonathan Epstein:
That's right. So probably most of the time, when a virus jumps from animals into people, it doesn't really go anywhere. It might cause a few infections, but based on the ability of that virus to efficiently spread from person to person, most viruses aren't that capable, and so you might get a few cases or an isolated outbreak, but then it goes away in people and it stays in that animal reservoir and it may occasionally cause little localized outbreaks.
What we saw with SARS-CoV-2 was when it made the jump to people, it was already able to spread efficiently and rapidly spread around the world, and now, it's in the process of really establishing itself as a human virus. I mean we're probably at a point where so many people are infected and there are still so many people the virus can infect that it will continue to circulate and become what we call endemic in people. So this would be an emergence of a new virus that becomes a human coronavirus ultimately and so different viruses have different abilities to do that and it's probably more often the case that it doesn't happen, but it's what we're probably witnessing right now with COVID.
Sabrina Sholts:
Yeah, and that would make it ... Which of how many coronaviruses that are endemic among people at this point?
Jonathan Epstein:
Well it's really the seventh known coronavirus to infect humans but prior to this, there were really just four that circulated and most of them, coronaviruses in people were responsible or associated with common colds. Very, very mild viruses. It's why we never really paid much attention to coronaviruses until SARS emerged, and that caused a very serious pandemic, where with the original SARS outbreak in 2002, about 9% of the people died. That's more than triple what COVID is doing, and fortunately though it was easier to contain for reasons such as only symptomatic people spread SARS and so you could identify who was transmitting and isolate them and public health was able to eventually contain SARS. But COVID is so much more difficult because of asymptomatic transmission. So it's very spreadable, very contagious, although it has a lower fatality rate.
So this may be the fifth human coronavirus that really establishes itself in people, and it may be that we end up managing COVID as a seasonal illness or a mild illness or recurring illness, and we're going to have to wait and see how that shakes out. But fortunately we do have vaccines to really help protect people from serious illness due to COVID and so it's likely to become a manageable disease ultimately. But it's really still in the process of establishing itself and emerging.
Sabrina Sholts:
Yeah. Well, this is fascinating Jon, and we are starting to get questions from the audience. So if you are all right with it, let's take a few of those, and actually ... With this first one, we're going to, certainly we're staying within your wheelhouse. It's a question about bats, which I know you could tell us so much about, and it's from Richard asking, "Why are bats a particular concern? Should they be?" I think concern about ... Reservoirs of emerging infectious diseases.
Jonathan Epstein:
And it's funny, if you walk through the exhibit, the outbreak exhibit, you'll see that a lot of the diseases that we've experienced with have an association with bats but I'm going to start with a positive message about bats. Bats, when it comes to biodiversity, bats represent about one-fifth of all mammals on earth in terms of the number of species. So second only to rodents in terms of all the different types of bats there are. More than 1,400 species, and bats play a really important and beneficial role ecologically for us. There are bats that eat insects that really work to control agricultural pests, like moths and beetles. So a natural pesticide. Then there are fruit bats, fruit-eating bats, particularly as you see there a model of one, that are really important in terms of pollinating trees and dispersing seeds and so in nature, bats play an indispensable role.
Now by same virtue, because there are so many different types of bats and every species of animal is associated with its own community of microbes, bacteria, viruses, most of which are benign and some of which might cause disease. So by sheer numbers, we have a lot of opportunity to be exposed to bats, and I don't even mean directly being bitten or scratched by bats but more to the point of living in the same environment as bats, where we might be exposed to their excreta, so contamination of food with feces or urine, or people who go into bat caves to harvest bat guano as a fertilizer which is a common practice but might get exposed to viruses or bacteria or fungi that are contained within fecal material within the guano. So bats live everywhere people do on all six continents, and there's a lot of opportunity for exposure.
And because they're so diverse, there's a great commensurate diversity of viruses, some fraction of which have that ability to jump and now we have seen associations between some pretty well-known zoonoses, like Ebola and related viruses, Nipah virus which you see here which is a virus carried by large fruit bats across Asia that causes a very severe central nervous system disease when it does get into people, and has a very high fatality rate, about three-quarters of the people who get infected die from this disease. But it's been pretty relegated to parts of South and Southeast Asia so far.
So bats are associated with viruses that can cause pretty bad disease, and there's data to suggest that they may disproportionately carry viruses that can be pathogenic. What's interesting is we're just starting to understand that bats seem to have a different way of coping with viral infection than people or other mammals, and that is that they seem to be able to get infected with viruses and not suffer significant disease and sometimes not any disease and they're able to then deal with that virus, they transmit the virus, and they clear the virus, so their immune system works a little differently and that's been really interesting and it's a new field of study.
So bats do, they're not the only reservoir certainly for viruses that can impact people, but we are finding that there are associations between bats and zoonotic viruses. But the same is true for rodents and for non-human primates as well.
Sabrina Sholts:
When you think about that they're everywhere that we are, and therefore so much of what we do can intersect with what they're doing, which is certainly not trying to infect us but that is what happens, and we were looking at that Nipah section of the exhibit, which was such great fun to create that tableau with you, Jon, knowing that it was all based on your work and your colleagues' work, illustrating for example transmission of that virus from bats to people via [inaudible 00:38:39]. That's one example of how that can happen. In Malaysia, I know a different example via pig farms. So we've got a question here from Alyssa and you can certainly ... It's a general question, so you can talk about certain pathogens or examples if you like, but she's wondering "how common is the transmission from animals to humans and back to animals?" I imagine it depends, right?
Jonathan Epstein:
I think it's a fantastic question and the honest truth is we don't know the answer to that because it's actually pretty rare that we witness it. I'm sure it happens way more than we're away, but I'll give you an example. COVID is a situation where we're seeing and being able to document evidence of animals getting infected with SARS-CoV-2, the virus that causes COVID, where it's clear that they have been exposed to people who are infected and they're getting infected. But in other instances, we're just not paying careful enough attention to wildlife and other animals that might be infected by human illness. Now there are great studies that are shown, for instance in parts of Eastern Africa where people use human excrement as fertilizer. So they put human feces on crops to help fertilize it, and there have been local monkey populations that have been infected with bacteria that are only found in people's gut. So we know that we're sharing our pathogens with wildlife when we contaminate the environment with sewage, whether it's through fertilizer or through runoff with agricultural runoff or water, and the same is true for livestock, pathogens that may make their way into wildlife through agricultural runoff on farms.
So we do have examples that we've seen through research and study of wildlife getting exposed to livestock or human pathogens. But we just don't know to what extent that happens or how significant it is typically in terms of the health of wildlife populations, or whether it comes back again to people from there.
Sabrina Sholts:
Yeah. That was [inaudible 00:40:50] communication of what we don't know or what we're still learning, Jon I have to say.
Jonathan Epstein:
So much [inaudible 00:40:55].
Sabrina Sholts:
Yeah. There's a lot, yeah, obviously. We have a question here from Dorian, and it's switching gears again. Actually, I think this one goes back to the hotspots map and what you're doing at EcoHealth Alliance. The question is, "Do you use any satellite products such as data from NASA to help advise you when you predict, monitor and respond to outbreaks of vector-borne and water-related disease, and if so, which products?"
Jonathan Epstein:
Great, terrific question and the answer is yes, absolutely. Some of the research we do at EcoHealth Alliance looks at vector-borne diseases which are diseases spread by mosquitoes or ticks or other arthropod vectors and particularly with diseases like Rift Valley fever, which is a disease that impacts livestock in Eastern and Southern Africa, some of the patterns of outbreaks and infection can be tied to rainfall and periods of booming of mosquitoes and lower ... When it's dryer, there are fewer mosquitoes, and so remote sensing data, satellite data that looks at weather patterns, historical weather patterns and ties them to patterns of diseases outbreaks is really important for understanding and predicting outbreaks. So the answer is yes, we are using remote sensing and satellite data to answer some of these questions, particularly with vector-borne diseases.
Sabrina Sholts:
Very cool. Mariah wants to know what additional steps you recommend to be implemented to reduce global wildlife trade. "How can we improve enforcement of existing regulations internationally?" Do you have any thoughts about that?
Jonathan Epstein:
Oh yeah. It's an area of really intense debate right now, particularly with the notion that the original SARS and trying to understand whether COVID was associated with wildlife trade and wildlife markets and there are certainly other diseases as well that are linked to that, and there's evidence to show that wildlife trade can act as, the process can act as an amplifier for viral infection in animals that are going through market systems. So the question is what to do about that and there are a lot of different camps or sort of opinions about what the best approach would be, ranging from banning wildlife markets full-stop to monitoring and regulating them better to limiting them to species that are not considered to be high risk.
I think while there isn't one answer yet, I think it's important to understand that wildlife trade in some cases is linked to people's livelihoods. So it's never as simple as saying you can't do this anymore because now you're leaving people stuck with no source of income or nutrition and so it's very contextual in terms of what wildlife trade looks like in different parts of the world and different societies and I think that policies have to take that into account and think about it. But it is clear that more resources do need to be put into monitoring wildlife trade to reducing illegal wildlife trade, that's certainly important for biodiversity and so that means more resources into enforcement, into detection and really cracking down on what is really what amounts to organized criminal entities that are trafficking animals and animal parts around the world that contributes to loss of biodiversity and disease risk.
Sabrina Sholts:
Yeah, it's ... Enormous problems and actually, we're almost at the end of our conversation, Jon. I think we have time for one more question, and this one sort of follows up on what you said. I think it's a good question that relates to these huge challenges. "If we take human population growth as a given, what kind of development practices are going to help us reduce our risks for new zoonotic diseases?" So if we take population growth and density as a factor and I don't know, our food systems. What do you think? Do you have any thoughts on that?
Jonathan Epstein:
Because we understand that there are only a finite number of pathways that viruses tend to be able to get from wildlife into people, we can really focus on activities that we see as intensifying. So yes, with a growing human population and more demand for nutrition and protein, animal protein is a consequence of that so farming, intensified farming, but we can think about more alternatives to live animals or think about improving biosecurity around farming activities to really limit contact between wildlife and livestock as one measure to do what we're doing in a safer way.
We know that when we're developing cities, urban environments, suburban environments, we have to think about what that's going to mean in terms of pressure it puts on local animal communities, local ecosystems and how it might influence contact with people, and in thinking about that ahead of time, we can work with private industries, developers, multinational corporations that are actually driving land use change to think more strategically about the type of land they're converting.
Not all parcels of land are equal. You can think about doing what you do on land that has less biodiversity and will be less impactful to intact ecosystems and perhaps have lower risk for disease emergence, and we have worked with private companies and governments to think in that way. So I think we can anticipate some of these problems, but we can do them in a safer way, do these activities in a smarter way, and in some cases really just reduce and limit some of these activities that create risk for emergence.
Sabrina Sholts:
So we need to think about one health.
Jonathan Epstein:
We need to think about one health.
Sabrina Sholts:
Every day, not just on One Health Day?
Jonathan Epstein:
And it's not just for scientists. This is something to think about as consumers in the products we buy to continue to pressure companies that are driving a lot of global change to think differently about how they're doing that and I think one health really requires partnerships with private industry as well, not just with governments or scientific entities.
Sabrina Sholts:
Well Jon, with that, I think we are going to have to bring this conversation to a close unfortunately but it's on a nice note to remind everyone why we're speaking today and hopefully, I know that you've given folks a lot to think about and thank you so much again for your time and for all that you do.
Jonathan Epstein:
Yeah. Thank you.
Sabrina Sholts:
I would like our audience actually to virtually join me in thanking you and I also want to give a special thanks to those people who have helped make this program possible for us. Our donors, volunteers, those of you watching, thank you for your support and of course all of our partners who help us reach, educate and empower millions of people around the world today and every day, thank you.
So if you enjoyed today's event and you're interested in learning more about our other programs including our upcoming Outbreak series that will explore stigma and HIV/AIDS, that series is going to kick off on World AIDS Day, a very special day indeed for us, that's December 1 at 5:00 p.m. Please check back for more information and you're also going to see a link to a survey in the Q&A. Please follow that, please take a moment, please respond. We're really interested in your input, it's going to help us make these programs better and bring you more great content. So finally, again, thank you all, and I hope to see you again next time. Have a great day and a happy One Health Day.
