Ep 128: Homo pathogenesis? (with Sabrina Sholts)
How does human behavior contribute to disease transmission? What can our history with infectious disease teach us about modern epidemics?
On this episode, we talk with Sabrina Sholts, Curator of Biological Anthropology in the Department of Anthropology at the Smithsonian’s National Museum of Natural History (NMNH). Sabrina’s research explores the intersection of human, animal, and environmental health. She was the lead curator for the exhibit “Outbreak: Epidemics in a Connected World”, which inspired her new book, The Human Disease: How We Create Pandemics, from Our Bodies to Our Beliefs. In our conversation with Sabrina, we discuss what it was like to curate the Outbreak exhibit, how human social behavior can underpin pandemics, and the historical context of infectious disease.
Cover art: Keating Shahmehri.
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Cameron Ghalambor 0:06
Hey, Marty, so, as you might predict, it's pretty cold and snowy here in Norway today.
Marty Martin 0:10
You don't say. Cam, you know, I feel like half of our conversations these days start with you grumbling about the weather.
Cameron Ghalambor 0:12
Okay, sure. But I do love Norway, aside from the cold and darkness. And speaking of cold, I was actually super sick last week, and I started thinking about cold weather and the word cold and how they kind of like are related to one another.
Marty Martin 0:37
Let me guess it has something to do with the idea that maybe you got sick from the cold?
Cameron Ghalambor 0:41
Sort of. According to the Oxford English Dictionary, the word cold was first used to define illness back in the 1400s. It was used to describe symptoms that were similar to those someone would experience due to cold exposure, like a runny nose, shivering, and red eyes.
Marty Martin 1:00
And after 600 years of medical research, moms across the world still warn us to wear a jacket when we go out so we don't get sick.
Cameron Ghalambor 1:08
Yeah, I know that blaming cold alone for making you sick bothers you, being an infectious disease researcher and all.
Marty Martin 1:16
Yeah, because becoming infected by one of the viruses that causes the common cold has nothing to do with cold temperatures!
Cameron Ghalambor 1:23
Oh, you can see you're fired up now, but at risk of poking the bear, why are respiratory infections much more common during cold months compared to like the summer?
Marty Martin 1:34
Well, there's a lot of ideas about that. My former mentor, Randy Nelson, who's chair of neuroscience at West Virginia University, he makes the really strong case that some of these patterns have to do with seasonal rhythms in our immune system. But that's a story for another day. A different reason for sure is that when temperatures get cold outside, people tend to spend more time gathered inside- eating, talking and spreading their pathogens around.
Cameron Ghalambor 1:57
So people came to associate cold weather with the symptoms of viral colds, even though temperature itself has little impact on getting sick?
Marty Martin 2:08
Well again, sort of. High body temperature or fever definitely plays a major role in mitigating some infections. But many animals even become heterothermic when infected, they ramp up and they cool down their body temperatures for reasons we don't yet understand.
Cameron Ghalambor 2:22
Okay, okay, but we're talking about people's behavior and how it influences the spread of disease. You can save the immunity lecture for another time.
Marty Martin 2:31
Okay, fine, but especially because our guest today, Sabrina Scholts, a Curator of Biological Anthropology at the Smithsonian, has a lot to say about how human behavior and infectious disease come together. Her new book, "The Human Disease: How We Create Pandemics, from Our Bodies to Our Beliefs," summarizes how infectious disease has been so consequential, and our evolutionary past and our modern experience.from smallpox
Cameron Ghalambor 2:52
From smallpox to Ebola to SARS2, pathogens have left a major mark on human populations.
Marty Martin 2:59
And Sabrina's perspective is that that mark has been so profound because we're such a social species.
Cameron Ghalambor 3:05
Sabrina's book derives from an exhibit she led at the Smithsonian Museum in Washington, DC, which debuted just a bit before the COVID pandemic overtook all of our lives.
Marty Martin 3:16
That exhibit, which was called outbreak, was an inspiration for her to dig more into the details of our history with infections.
Cameron Ghalambor 3:23
Thanks for your support.
Marty Martin 3:24
I'm Marty Martin
Cameron Ghalambor 3:25
And I'm Cameron Ghalambor
Marty Martin 3:26
And this is Big Biology.
Marty Martin 3:40
Sabrina Sholts, thank you so much for joining us today on Big Biology. We're going to talk about your new book,"The Human Disease: How We Create Pandemics, from Our Bodies to Our Beliefs". I really enjoyed it. It was a great trip through our history with infectious disease, from back before the time of dinosaurs right up to modern day pandemics like COVID and Mpox and avian flu. So we're going to get on to a lot of those in just a minute. But I have to ask, how did you get into this area and the Outbreak exhibit at the Smithsonian, which I understand was sort of the one of the main reasons for writing the book. So you're a biological anthropologist, but working in the Smithsonian on an exhibit about infectious disease that led to a book put those pieces together for us.
Sabrina Sholts 4:28
Yeah, I know it's not a it's not a typical story, and it's really not a typical place to be a biologist anthropologist, you know, the a museum or a natural history museum, particularly this one, which is a public museum, and therefore there's a component of public service, you know, I think, and public engagement that is just intertwined with everything I do. So, you know, when I arrived here 10 years ago, okay, it was 2014 I was, you know, I have been following this very traditional path in academia, thinking that I would probably end up being a professor at a university, you know, teaching and doing research and so on. You know, you look on my CV, for example, there's no preparation, nothing in my record to show that I was preparing to do an exhibit or any kind of, you know, public communication that way. I don't have a certificate in Museum Studies. I don't have any extensive expertise with that kind of project. But, you know, I did arrive with, you know, a good background in biological anthropology with some big ideas in how human health is connected to everything else around us.
Sabrina Sholts 5:39
And you know, in that particular moment, this was in early 2014, I was just fixated on what was happening in West Africa, which was an emerging and quickly becoming out of control epidemic of Ebola virus disease And so, you know, as that progressed, it just became more and more worrisome. This was a part of the continent that had not experienced the disease before. The healthcare systems were so quickly overwhelmed. There just was a confluence of factors that just made this a really, really frightening situation of how fast the disease was spreading and how many people were being infected and dying. And amid all of this, you know, little did I or anybody else know here at the museum that there was one of those disease physician by the name of Dan Bockmann. He was out of those front lines, you know, trying to treat patients, and had this idea, you know, he was based in Washington, DC, and I think he had it for quite a while that this, and so you should do an exhibition about outbreaks, about epidemics that have a zoonotic origin, but they're caused by pathogens, so they're shared between humans and other animals, and that are often spilling over from, you know, our livestock, our food animals, and have some sort of origin wildlife, which we believe was the case with with Ebola in 2014 and so many other examples. And so it was really an idea that came from Dan, and he proposed the idea to the museum that we should do the exhibit. I was a brand new, fresh curator with enough knowledge, you know, to at least step into the role of the lead curator to do this exhibition. But it was a huge team that came together to do this work.
Sabrina Sholts 7:30
And so, you know, we decided that, yes, this museum is not only a place that can tell this story right as a natural history museum, we can look at that interface, we can show that point of emergence, that the place of humans within the natural world, as part of the natural world, that is, you know, a big part of all of these activities and other human drivers that contribute to these outbreaks, help people understand that story and see in a broader context, as well as, you know, to be a place that should tell that story, because we do have so many visitors, because, you know, we are the National Museum. And so that was where it all started. This is a major exhibition that we began to work on, 2014 we had, as I said, a lot of people on board, a lot of agencies and collaborators and partner organizations. This is, you know, everybody from folks at NIH to the Fauci, you know, came over quite early, as well as WHO and CDC and so on and so forth. And to, you know, provide this experience to help people just better understand, not only you know, where pandemics can come from and have and do, increasingly in the 21st century, but also things we can do collectively and individually to stop or prevent or reduce the spread of infectious disease.
Marty Martin 8:38
So I've never seen Outbreak. I think. I can't, I can't exactly remember why I know it was in DC at the time. But how much was it based on Ebola? It was a smattering of all sorts of zoonotic diseases, but the impetus was Ebola. So was Ebola featured? Or can you give us just a snapshot of, you know, what it was comprised of?
Sabrina Sholts 9:06
So the exhibit had the main message of One, Health, okay, that human, animal, environmental health, are all connected. All of our exhibits have a main message, you know, something very succinct, you know, something short that people can just, you know, kind of see, and hopefully remember, even if they're just walking through to find the diamond or the dinosaurs or the bathrooms, which I think a lot of people do. And I'm not surprised that you didn't see Outbreak, most people didn't. But within that theme, we just want to tell stories. Ebola was certainly one of them. It was the catalyst. It was featured in a section that actually was focusing on the role of healthcare workers helping address and, you know, and fight against an outbreak. We featured, you know, this tableau of like an emergency treatment unit like they had in West Africa. This was focusing on the community, you know, that had to sort of come together and change behaviors in order to reduce those risks. Other diseases, they ran the gamut. I mean, we focused on viruses, actually, zoonotic viruses, and those that lend themselves to stories, or certain aspects of stories. We talk about Nipah virus in Malaysia and Bangladesh that we're certainly looking at, you know, the interface of humans, animals and the environment. And sometimes you can catch it, you can catch an outbreak before it becomes an epidemic. We actually had a whole section about coronaviruses, right? That that was our that was our feature of, like the international spread of disease, alright. So keep in mind, we started developing this in 2014 it opened in 2018 you know, Covid did not exist at that time. And so there was, you had MERS, you had SARS, that was the big story there. Which, of course, have so many parallels with what we saw happen with Covid-19, Covid-19 being how things went wrong. You know, you go from that section about SARS and MERS, and we added some about Covid-19 to the pandemic section. That was a section that featured HIV/AIDS, because that was at the time we're developing the exhibit in our mind, and I think still arguably, the pandemic that defines our time.
Cameron Ghalambor 11:12
Okay so you have this exhibit Outbreak. And so how did you go from working on the exhibit to then transitioning to thinking about writing a book and maybe you could just tell us, maybe briefly, about what you wanted the main message to be, and who you wanted to target in terms of your audience.
Sabrina Sholts 11:41
Sure. Well, I was not thinking about writing a book, to be honest. I mean, the exhibit itself was very well consuming and a big, big project. Yet, you know, as I mentioned, like we opened in 2018 and, okay, everyone, you know, that's great. It's exciting to see it open, have it conversations. But come 2019, end of 2019, early 2020 all of a sudden, you know, we and every other place around us, is shutting down. Right? The Smithsonian basically closed to the public for a period of time in March 2020. So I liked most of the rest of us was at home. I was at home, unable to do any lab work and the research that, you know, I was just planning to do at that moment, still trying to communicate and do what we could to reach the public, even though our doors were shut. And so we started to do virtual programming. You know, that was, that was my first experience with webinars, and, you know, zoom and all of this.
Sabrina Sholts 12:51
And so the first series that we decided to put together was about vaccines in a time of COVID 19. We did this before there were any vaccines for COVID 19. But you know, we had colleagues, some of our Outbreak supporters were part of developing these vaccines, NIH, for example. And we knew that the public was going to have questions about everything from how are they made, to manufacture and tested and then distributed? And then, you know, so from an anthropological perspective, what happens when, you know, we have to go from vaccines to vaccination and people need to accept them. And so it was through the course of actually doing this webinar series that people start tuning in. And one of them happened to be involved in publishing, and reached out to me and suggested that, you know, had I considered outlining, you know, maybe proposing working on a book related to the exhibit, but also building on the work that went into it. And so I hadn't, but I thought, I thought that I might give it a try. It was really difficult to see how at that time again, you're at home like everyone else, you're depressed and scared like everyone else you know, there's also been a million people out there giving their opinions, weighing in and, you know, being the person that everyone should listen to, thinking that I had something different to say, or important to say, you know, I had to sort of think about what that would be. And in thinking about it, I did realize that I had not read, and I read a lot about pandemics, epidemics, all through this subject, I have not read anything that put together the unique and special human features and factors that contribute to the spread of disease, why humans are so good at spreading disease. And that's what, that's what I wanted the book to be about. I hope that what people take from the book is the understanding that, you know, pandemics reflect, you know, many of our unique human features, both you know that work work against us. You know in ways that we are in some ways uniquely good at spreading disease, but also some things that can help us if we choose, the brain power that we have, the adaptability of our species. I mean, that is just an extraordinary capability that, you know, we can harness if we choose and if we understand. So I think we just have to understand, you know, we have to understand where our risks are, as well as our opportunities. And, you know, with all of this couched in a broader perspective natural history, I do hope that people take away the understanding that you can't understand pandemics, not understanding natural history, and that humans are part of natural history,and the natural world, not separate from it.
Cameron Ghalambor 15:29
So I'm not a disease ecologist like Marty, but when I was in grad school, I became obsessed with Richard Preston's book The Hot Zone, and I think that was my first time really thinking about how a pandemic and how disease could really how scary it could be. And I guess you allude to this in the book, and in the time since, I think maybe some of the symptoms of Ebola were a bit exaggerated in that book. But it also, I think, you know, sent a message about, like, at least for me, this how you deal with the balance between educating people and communicating the severity of potential pandemics. I mean, in a time before we had to deal with the global pandemic versus like, what the appropriate level of like, caution or vigilance should be? And I'm curious, like, as you were writing this book, did you, did you have, were you consciously weighing, kind of, the two sides of like, trying to educate and be honest about, like, you know, here are the real threats versus not being alarmist or, I don't know if that's the the right contrast, but, but do you know what I mean in terms of, like, finding that balance?
Sabrina Sholts 16:54
I do. I do. It's a good question, and I struggle with that a lot. Actually, certainly that's something we thought about in developing the exhibition. Again, the exhibition was about before Covid-19, so people had, very few people had any experience with the pandemic personally, right? Certainly not that they spend Covid-19 the way everyone has now. And we try to be as not positive, because it's not the right word, but I suppose you know you what you want to give people some hope, or at least you want to give them something that they can do. Action is hopeful. Knowledge is hopeful. It makes people feel empowered. It does empower people to learn more and to do more just by better understanding something that maybe they didn't before. And so with the exhibit, for example, we had this visual motif, you know, called on the upside. It was an up arrow, and it was a way where you could, you could read about something. And maybe this is a very maybe it's something very difficult, or, you know, sort of some new information, and then that might be depressing or scary, and then something that would point to, you know, some success with a research project, for example, or initiative in order to, you know, control an outbreak of a sweater disease, or just letting people know something that they could do that would make a difference potentially.
Sabrina Sholts 18:27
And so with the book, I always kept that mind that was really hard to do in 2020, 2021, sitting there trying to be positive about anything particularly in the US at that time, seeing so much going on that, you know, just seemed like just, it was just, it was really upsetting. You felt a lack of control over any of it. In Washington, you know, that's a whole different level of, you know, difficulty. And so trying to bring that to the book, and I, I thought very hard about trying to be clear with some of the messaging. And so the main ideas that are, you know, a bit nuanced. I don't want people to come away from the book thinking that, "Oh well, you know, because you know what I do to spread disease, that's, I'm just human. That's just being human. I'm human. Nothing I can do about it, and don't blame me for it. I'm human." That's not really what I'm trying to get at. Like, yes, there are things. Are just things humans do, okay, ways that we bury and care for our dead, for example, you know the role of funerals for disease transmission, I talk about that, but it's very much a human thing. The same with gathering together and sharing food all right, in restaurants and other contexts, commensality, okay? Again, that is uniquely a human thing, extents to which we just need to share food and drink all time and time. Talking, talking to each other, when we gather in person like we are the only species that has that, such a sophisticated, complex, amazing system of communication. We have any other unique anatomical, you know, and cognitive traits that allow for that. That is all being human. But I argue that because of all of that, in addition to just our extraordinary intellectual capacity and abilities for innovation and adaptation that that's not an excuse. That is with that knowledge of what our risks are, that we can make better choices, better informed choices, and we can actually use that information to make ourselves and each other safer
Marty Martin 20:34
Yeah one of the mantras I preach on my evolutionary medicine class. That might be an explanation for human behavior, but it's never an excuse.
Sabrina Sholts 20:40
I know, and I think that just understanding can make people feel better. So that's what again, I tried to just find hope in not necessarily you know that we're going to prevent something on the scale of COVID happening again. I know. I say very clearly that there will be another, but you know, the extent, the scale, the magnitude of harm and disruption, that is to some extent, in, you know, literally and figuratively, our human hands. And I hope that people find some assurance in that, that if we're part of the problem, we're also a big part of the solution.
Cameron Ghalambor 21:22
So it'd be good to maybe cover the the sort of historical context of how, how we came to know what we what we know, and and I, I really enjoyed reading about the the historical factors and people that were involved in in discovery of like, things that now I think we we often take for granted. So you mentioned Pasteur, but you also talk about Mervyn Henry Gordon and his experiments in the chamber of parliament in the UK. Can you talk about like, how he helped us or helped the parliamentarian sort of understand their role in spreading disease?
Sabrina Sholts 22:07
Sure. Yeah, I like that story a lot, actually. And, I mean, so what we're talking about, right and germ theory, right? Which, you know we, certainly, most of us accept today this theory that, you know, many diseases are caused by specific microbes. I mean, that was first proposed kind of, by Fracastoro, this Italian scientist in, like, the 16th century. But not really it was just sort of, if you were the germs, the seeds of that theory began at that point. You know, we didn't have any visualization of microbes until van Leeuwenhoek, you know, with his, with his microscope, in the 17th century. And then, you know, just not until, you know, we reached the golden age of microbiology, really, in the mid, late 19th century, right? That we start to see this really extraordinary period of scientific innovation and discovery, right, into which Mervyn Henry Gordon enters. I always try to think about what people knew, so what was accepted, and what was controversial or unknown at any period or any point of research, right? Especially the really impactful studies. And so for him, I mean, there were tools to see and photograph bacteria. There were these processes, you know, for manipulating and filling them, like pasteurization, right? So, like growing a virus in new environments it becomes less pathogenic. And then these techniques for culturing them right? So just by growing experimenting with bacterial colonies, people were doing that at that time with agar plates, these petri dishes, you know, so that you know, they could, really, they could, they could grow these, these microbes in this gel, so that it's stable, you know, and they can do things with it.
Sabrina Sholts 24:04
And so all this was sort of, you know, underway and available in it was 1903 when the House of Commons in the UK Parliament was hit by a wave of flu. And so this bacteriologist, Gordon, he was brought in to investigate whether the air, you know, or the, basically, the contamination of the debating chamber in the House of Commons that that might have been something to do with it, you know, It's called the debating chamber, of course, because that was where the MPs would would get their speeches, you know, and gather and talk, or, as Gordon described it in his, in his in his writings, or they would articulate loudly, right? And, you know, you really ask the question, you know, could this have a role in possibly contaminating the atmosphere, right, with their emissions? You know, respirator emissions as they were speaking. And so in order to figure out how far microbes might travel from a single MP, a single individual giving speech in the debating chamber, and like, what kind of infection, you know, just one order might be able to cause. What Gordon did is that he gargled with this liquid culture, the bacteria
Marty Martin 25:14
Sacrifices for his work.
Sabrina Sholts 25:16
A bacterium yeah yeah yeah, which, at that time is thought to be, thought to be a harmless it's not. It's not that's something we know today. It's an opportunistic pathogen. But we have no record that he was harmed for this experiment, thankfully. And so he filled his mouth with his microbes, basically. And he got up to this dispatch box where give their speeches. And I love this part of it. He spent an hour just reciting Shakespeare, which just sounds lovely. I mean, what a fun experiment, right? And his audience for his Shakespeare, for his recitations, was just rows and rows of agar plates at various distances from where he was standing. And so what he found was, just by speaking, just by doing that, as any one of the MPs could have done, these plates were producing a dark colonies of the bacteria as far as, like, 21 meters away. Okay, we're talking 40 feet or something like that. Just a really, really far distance. And so that experiment that was, you know, supported by and consistent with others, you know, that followed in, you know, ensuing decades and even, you know, especially during the 1918 influenza pandemic, reinforcing the role of speech and respiratory transmission. I think it's really, it's, it's interesting to, you know, see what people were able to know, you know, at that time, just with the tools that were available.
Sabrina Sholts 26:34
But also what they didn't know. For example, at that time, no one, no one could see a virus. You know, they had an idea what a virus was, but they weren't seen until the development of electron microscopy in the 1930s and I don't know how well they even really understood what the mechanisms of respiratory transmission were, you know, or what about speaking, you know, actually allowed that to happen, that kind of, that kind of transmission. And we do have some great research that's come out of recent studies that are shedding some light on those questions as well. You know, we know that, you know, when we speak, you know, we're generating these very tiny particles, you know, that are emitted, and that they can carry very small pathogens, like measles virus, for example, or COVID 19. And because they're so small, they can hang in the air for longer than, say, you know, particles produced by a cough, right? And they can also kind of penetrate further down into our respiratory tract, you know, of someone who's susceptible. And so in these ways, I write in the book, you know, speaking can play a larger role in respiratory transmission and actions, and then we realize even more than, you know, maybe coughing or sneezing, and that feels to me with the way that the vocal holds vibrate, you know, when we're speaking, there's a lot of complexity that goes into it, but Mervyn Gordon, his work certainly, I think, plays a really interesting and fun contribution to your understanding. Yeah,
Cameron Ghalambor 28:03
Yeah I think what, what struck me about that was it was a relatively straightforward, simple experiment, but also something that, like anybody could really easily grasp. And so, in a way, it's more powerful, in terms of communicating spread, than, you know, more modern, sophisticated ways that we might, we might talk about, you know, how a disease spreads. And I really appreciated reading that, and thought like, you know, everybody should know about this kind of study, because it really makes it obvious.
Sabrina Sholts 28:42
Yeah and I tried to highlight studies and explain, you know, research in a way that I hope to be very accessible and have that kind of effect. You asked me, who was the target audience for the book, and I always tell people like my mother, you know, or just like, and my Mom is a smart woman, but she's not an academic. And you know, she knows as much as she knows by being with my mother about this stuff, but, you know, likes to learn new things. And I did, you know, there aren't any graphs or figures that I felt were overly complicated in this book. I actually simplified a few of them. I tried to just make them very understandable. I mean, if I needed more than a glance at something to really understand what it was doing, like it I felt like, in some ways, you know, somebody misunderstanding, you know, something that's been published because over complicated. Can do us no good. So, yeah, with that study and others, I think, I think that there are some pretty compelling and easy, understandable ways to represent and communicate this information.
Marty Martin 29:50
Yeah. So I think that you know that this whole section of the book, when I initially started reading it, I was skeptical about the sort of your standpoint that. Humans are exceptional with respect to, you know, either getting or amplifying or transmitting or, I guess, I guess we're pretty bad. Maybe, is your message. "Bad" in the sense of consequential for others, for a lot of others? And, yeah, I guess I wonder, like in the case of the of the talking, that's a unique, for the most part, human trait, lots of things, vocalize, but the but the part that stands out making us bad is not just that we speak, it's largely that others listen, right? It's that we're in these big groups, and for certain pathogens, there's no way to make new pathogens unless you find that that next host for the pathogen. So it's us speaking and somebody caring to listen. It's this disposition to be communicative and live in groups and live in intimate groups and have long relationships, like all of these other things about people that makes a lot of sense.
Sabrina Sholts 30:52
I think that's, yeah, that's really well put. And by the way, I do recognize that, you know, it's also sort of a tricky message, that the antithesis of One Health is anthropocentrism, okay, this idea of putting humans at the center of everything. I certainly don't want to do that, but here I am saying like humans are different, humans are special. At the same time that I do want to say that there's so much we share, you know, with other animals. We are an animal too. We are part of nature. We are not separate or, you know, so distinct or untouched by anything. We do have features that are, if not unique, quite special, quite distinctive of our species that, unfortunately, do, I argue, combined with others to create pandemic risks.
Marty Martin 31:41
Yeah, well, and it's hard to it's hard to argue against that for so many diseases. I think we should circle back to this but, but I actually brought this up Sabrina, because something about this section, it helped me realize it was because you introduced another conspicuous character in the history of infectious disease, Mary Mallon. So it's impossible to argue that Mary isn't a special wasn't a special human, because she's one of those focal points for this concept of asymptomatic transmission. So I guess, instead of talking about human behaviors that dispose us to be problems as regard disease, this is almost the lack of behavior like Mary didn't get sick and therefore created havoc for the rest of us. So, like that was a powerful way for me to thinking about. Think about, is it something that humans can do? What are the characteristics of humans that you know, maybe when other species get infected, they suffer. Are there things that happen to us when we get infected that dispose us to transmit, as opposed to getting sick and dying? And that was a pretty cool, a pretty cool example there. Well, thank you.
Sabrina Sholts 32:45
And I mean, for any listeners who don't know what we're talking about, so Mary Mallon, you might know her as typhoid Mary. She features in one of the chapters in the book, actually the section about our hands, the human hand as being a quite special vehicle of transmission, right? Because our hand is unique to the extent that you know, there's no other ape that has as long the thumb in proportion to the other fingers on the hands. And there's no other primate that can make, you know, the fingers, a pose so forcefully, which, again, there's it's sort of a combination of things. It's not that no other species can, can hold or touch things as we do, but to the extent that we do in the ways that we do, that's quite special. And so I tie that to Mary Mallon as another historical example of, like, what we knew when, right? So, I mean, this is again, in the early 1900s, right at the same time when Gordon was doing his experiments in the house of parliament over the UK. Mary Mallon was a household cook in New York City, making food for wealthy families, who happened to be a chronic carrier of bacteria that caused typhoid fever. A carrier means she infectious, but she didn't show any symptoms. And so, you know, she was shedding these bacteria when she used the bathroom, and she was carrying them with her into the kitchen on her hands because she wasn't washing them. She's preparing food, serving food, you know, causing a string of outbreaks in the families that eat her meals. Because, you know, it's not that she was trying to hurt anyone. She didn't see how being healthy could make someone ill, right? And so she didn't wash your hands. Public Health always tracked her down. You know, they were, like, telling her, maybe not in, like, the best ways and most convincing ways, you know, that she was infected with this bacteria, but she didn't buy it. She refused to stop. Her story also features, it appears again in the book, you know, sort of in discussion about personal liberties, you know, and how we balance public health with individual rights. But yeah, she she is certainly an example where she was predisposed to spread disease, because she's the asymptomatic carrier and spreader of the bacteria, but through her activities, through what she chose to do and what she chose not to do, you know, by not utilizing, you know, hygiene measures that were known at that time, by the way, known very well, being promoted, that that was another way that she was certainly not reducing risks of spreading and actually increasing them.
Cameron Ghalambor 35:12
Yeah, I had no idea that. I mean, I knew that she had been identified and arrested, but she was actually released and then got people sick again, and then rearrested a second time. And so that was really interesting. And I mean, you mentioned that she comes up again later, but, you know, we talk about these, the lesson of not being aware of what the route of transmission actually is. But then there's also just this like psychological component of like that also seems very uniquely human to be sort of in denial, and despite being presented with evidence that, look, you're you're spreading disease and you should wash your hands or be more careful or do something else, still, in the face of that, continue to do what you want to keep doing.
Sabrina Sholts 36:07
Yeah, there was certainly sort of a willful, you know, resistance, deny, on her part. But also it's a complicated story. You know, there are different aspects of it. I can see how Mary Mallon had no reason to trust the people who were investigating her and following her and arresting her and quarantining her, eventually, for the rest of her life. And alsoI'm not sure how much of a choice she had in cooking or not, if that was the only means she had to make a living, for example. The public health authorities in New York, they were aware of other carriers. She wasn't the only one. It wasn't common, but it certainly wasn't unique to her, and I think that she was not offered as many opportunities for education and rehabilitation and different means of making a living than perhaps somebody who wasn't a foreign born, frankly, poor female, she's marginalized from the get go. And that also, you know, ties into other topics discussed in this book.This "othering" being, you know, just a huge, huge factor in how we see and create difference that maps onto health disparities, because of how people are made more vulnerable, you know, and structurally, you know, disadvantage when it comes to the spread of disease.
Marty Martin 37:29
Yeah. So there's a couple of different things that you introduce there and in sake of time, I think that's that's perfect. One of them is about the context in which any individual finds themselves, and what role they can play. So let's really maybe talk about that one. First, there's so much that we could cover here, how many chickens there are on the planets, how big cities are and how much bigger they're going to be, but, but so if Mary Mallon would have lived thousands of years ago, and somehow we had the abilities to track it, would have been very different, because the densities of populations and the numbers of opportunities she would have had to spread is nothing like what it was when she was cooking in New York, when she was when she was active. So cities in the context in which people find themselves, what it means for an environment to be a city, it has a lot of different ramifications for infectious disease. So maybe talk about what you think to be what's most important with understanding the role of cities in zoonotic disease pandemics, and especially where we're going, because a lot of big cities right now, because where the biggest cities are won't be the same. You know, most of the big cities are going to be by 2100 in Lagos, Kinshasa, Dar es Salaam. So Asia and Africa are going to be the centers of human population, not necessarily where they are today. So how do we think about cities? And especially, how do we think about the futures of cities? Yeah, and
Sabrina Sholts 38:58
Yeah I certainly don't want to suggest that cities are like these centers of gravity and disease and filth, and I'm a city dweller life long urbanite. I love cities. They're incredible. Really, what we're talking about are some of the structural, just some of the factors that go into what cities are, or essentially, how they've developed, right? Because it's only in the past few thousands of years that we've seen this kind of massive growth of cities, and the kind of mega city that we're talking about. I mean, that's, that's, that's a really, fairly recent invention. Cities are crossroads of trade, essentially by origin, right? That's sort of how they came to be, that they are not places where you produce food, but as places where people live. Today, I think some of the biggest factors that make cities so vulnerable to these large outbreaks of. Infectious disease are, of course, the huge, densely populated centers. You know, there's so many people living in close proximity, interacting all the time. You know, within those sort of, you know, more defined spaces, as well as their connectedness to each other, not just roadways, but that's certainly part of it. I mean, what we saw going back to Ebola, which was, you know, sort of the start of a lot of this for me, Ebola in West Africa in 2014 because Ebola, that's not a new disease, and it wasn't at that time, Ebola had been known to science. In the 1970s there had been a number of outbreaks in different countries throughout Africa over the years are usually fairly contained and somewhat small, certainly compared to what happened in West Africa, which was, you know, by comparison of dozens or hundreds, you know, of people infected or who died. We're talking about, you know, almost 30,000 people who were infected, you know, around 11,000 who died, you know, within that short period of time. And what happened there was urban Ebola. Okay? Ebola reached a city, a major city, for the first time, actually, three of them, three capital cities in West Africa. And what allowed that to happen was the development of roads that were taking people there from more rural parts of countries into these urban areas, as well as how many people there were susceptible once that virus came to town. And combined with that, we saw Ebola in 2014 go overseas. Because what we have now are airports and global travel and trade. It is the global connectedness of our major cities that are also making it possible for a virus to essentially anywhere in the world within 24 hours, sometimes before anybody knows if they're sick. Right, and so that is something that, again, is a recent phenomenon since the 20th century, and that is what is driving some of what we're seeing, I think, with these increasing threats and the greater likelihood that we are going to see a pandemic, which we define as simultaneous, you know, occurrence, as a community spread of a disease around the world, different countries, continents all over the place, that that is just becoming more and more likely with the way that we're living, seeing, with the increasing urbanization of the world, more than half of us live in cities today. And as you say, that's not going to increase, but also that's going to be shifted to where people are living and what, what parts of the world you know that really, we're going to see a lot of that growth happening in the global South, in Africa in particular. And again, that is not to say that there's anything inherently Africa is not to blame for this or anyone there, but that is simply where we're going to a confluence of a lot of the factors, and where we need to be focusing our attention and thinking about, you know, where we need surveillance, where we need to be looking for those risk factors and building capacity and making sure that we're addressing those problems.
Marty Martin 43:02
Yeah. I mean, I think one of the dimensions, as you say, Africa is not to blame, but one of the things to be concerned about is that the origins of a lot of the zoonotic pathogens in the last several decades has come from some of the places that are being most extensively urbanized. And, you know, a lot of the spillover is just coming from more extensive and more intimate contact between human populations and wildlife. As cities are expanding into, you know, otherwise unmodified areas, it just increases the chance for something to leave bats or rodents, or whatever it might be, and enter human populations. So it's not only cities because of the cities and densities, it's the location of the cities on the world, and you know what has been the relative as the recent origins of most zoonotic pathogens?
Sabrina Sholts 43:46
Oh, yeah. I mean, certainly if we're talking about zoning machines, absolutely we're talking the the wildlife origins of some of these pathogens. I mean, where are those reservoir hooks, right? The bats that are natural reservoirs for Ebola virus, for example, or Marburg as another example. I mean, I actually speaking on Africa, you know, we had a very good example of an extraordinary successful outbreak response in Rwanda, where actually I work now, of their first, their first outbreak of Marburg, they were able to act very quickly and effectively, and they have largely contained it looks like. And just, you know, in a really efficient and safe way, this very, very dangerous virus with limited tools in terms of treatment, experimental vaccines and so that is possible, you know, but you just need to have, you know, people who who can identify the problem and act quickly and in coordination and collaboration. I mean, there was sort of some issue with that Marburg outbreak where you had, like the US getting out in front of it and saying, like, we're gonna start screening people who are traveling and all this stuff and not acting coordination with outbreak CDC. You know, we can do better. But. But you know, we do need to think about, as you say, not only these cities, and among all their different properties and characteristics, you know, where are they, and what is the ecological relationships that we're looking at, and what are the ecosystems that are being that are being impacted and changed by human activities, and what are those forces that are driving that kind of attraction, that are putting us at risk.
Cameron Ghalambor 45:24
It's interesting. So I'm, I live in Norway now, and two weeks ago, we got the official, sort of annual emergency preparedness sort of document. And it was, it was, is very interesting, something I don't think people, for example, in the US, are familiar with but it said, like, you know, basically, like, in the event of a natural disaster, you should be prepared to spend you should have, like, food for 10 days. You should, you know, be able to help your neighbor. You should have a source of heat. You should have a certain amount of food, etc, etc. But the thing that was most interesting was you should also be aware that during times of like concern like this, misinformation can also spread, and be very questioning of where that information is coming from, and make sure that you get your information from a legitimate source, and maybe it gave, of course, the government like, sort of like, news organization and arcade. But I guess, you know, all I was thinking as I was reading this is that, you know, although Marty and I try with with this podcast, to do science communication and and, you know, get the word out, a lot of people that live within, you know, certain bubbles, and this goes across the political spectrum, they they don't always get the right information. And to me, that seems like the one big challenge that we face. Because on one hand, we have the power to educate people in large numbers very quickly. And at the same time, we can also mislead large numbers of people very quickly. So yeah, it's an interesting time, for sure.
Sabrina Sholts 47:13
For sure, it is, it is, and I do take hope, inspiration, and certainly guidance and ideas from other countries. You know, I think it's really important that we look to each other the lessons. And that's very interesting. That's very interesting, you know, that misinformation becomes part of like, the warnings that one has to consider and needs in advance of a crisis. And I think that's absolutely true unfortunately,
Marty Martin 47:42
Yeah, well, Sabrina, we really appreciate your time. We wish you the best success with the book. We really enjoyed the chat, and before we go, we always like to give our guests the chance to sort of touch on anything that we didn't prompt you. Is there anything else you wanted to talk about that we didn't give you the chance to say, oh gosh,
Sabrina Sholts 47:59
I don't. And I would just say that, yeah, I when people are hearing this, you know, I'm trying to imagine what, what more will know or not know you know, where things will be in the world, and what the latest you know, sort of outbreak or epidemic might be in the news. And I do hope that you know this book remains among, you know, many that are out there. I think that people can look at some if they want to better understand, you know, what's going on that day or at that time, because, you know, this is, this is something that we have to, we have to be thinking about and talking about, I think more and more great.
Cameron Ghalambor 48:35
Great, Well, thanks so much.
Marty Martin 48:37
Yeah, thank you.
Sabrina Sholts 48:37
Thank you so much.
Cameron Ghalambor 48:52
Thanks for listening to this episode. If you like what you hear, let us know via Twitter, Facebook, Bluesky, Instagram, or leave a review wherever you get your podcasts, and if you don't like what you hear, well, we'd love to know that too. All feedback is good feedback.
Marty Martin 49:07
Thanks to Steve Lane, who manages the website, and Molly Magid for producing the show.
Cameron Ghalambor 49:10
Thanks also to interns, Dayna de la Cruz, Caroline Merriman, Brady Quinn for helping with this episode. Keating Shahmehri produces our awesome cover art.
Marty Martin 49:20
Thanks to the College of Public Health at the University of South Florida, the National Science Foundation and our Patreon and Substack subscribers for support.
Cameron Ghalambor 49:27
Music on the episode is from Podington Bear and Tieren Costello.