A century ago, the Spanish flu swept across the globe, wreaking such devastation that it earned itself the haunting title of “one of the deadliest disease outbreaks in recorded history.” All said, the pandemic is estimated to have infected 500 million people (one-third of what was then the world’s population) and killed at least 50 million of them.
We’ve learned a lot since then, but so have the diseases that threaten us. To try to understand what has changed since 1918, and whether we’re really prepared (or preparing) for the next pandemic, I spoke by phone with Sonia Shah, a science journalist and the author of Pandemic: Tracking Contagions From Cholera to Ebola and Beyond. Our conversation has been edited and condensed for clarity.
Mia Armstrong: 2018 marks 100 years since the Spanish flu, and obviously in those 100 years, we’ve seen other flu pandemics, we’ve seen other troubling outbreaks—Ebola, Zika, cholera. At the same time, we’ve also had a lot that has changed in our ability to detect and treat these sorts of diseases. Given all that, are we more or less vulnerable than we were in 1918?
Sonia Shah: I’m not sure I can answer more or less. I mean, we have more threats today, right? So over the past 50 years, we’ve had over 300 infectious pathogens that have either sort of newly emerged or re-emerged into places where we’ve never seen them before. We have new kinds of influenza, we have viruses like Zika—which has been around for a few decades but is now popping up in places where it’s never been seen before—West Nile virus, Ebola, tickborne diseases, drug-resistant bacteria. These are all relatively new pathogens that we’ve seen just in the last few decades. We have a lot more pathogens we have to worry about, and that’s because of the way we live now.
About 60 percent of the new pathogens we’re seeing today originate in the bodies of animals. [When you] put humans and wildlife into novel intimate contact, it creates sort of a bridge where the microbes that live in their bodies can come over into our bodies, where they can become pathogenic, and Ebola’s an example of that. Human invasion of wild habitats continues as our cities grow, as our industrial activities expand, etc. We’re creating new opportunities for these pathogens to amplify. Around half of the human population [live] within cities now. By 2030 or so, the majority of people will live in cities, and they’re not going be nice tidy cities like Washington, D.C. They’re going to be cities like Freetown and Monrovia in West Africa. We’re going to have a couple billion people living in slums.
What can go wrong when people are living in those types of conditions?
So, when we’re crowding people together like that in places where there’s not a lot of infrastructure, we create opportunities for these pathogens to spread from one person to the other. And we saw with Ebola in 2014, that already is creating opportunities for what might’ve been a small outbreak in the past to become a major regional epidemic. Before 2014, we had Ebola outbreaks since at least the ’70s and probably even before that unrecognized, but it had never gotten into a place with more than a few hundred thousand people. But within weeks of breaking out in the Guinea forest region in 2014, Ebola spread to three capital cities with a combined population of like 3 million people.
And it’s not just humans that are crowding. We also are crowding all of our livestock together, which is an undernoticed risk factor. We have more livestock today than in the last 10,000 years of domestication until 1960 combined. A greater and greater proportion of them live in sort of the animal equivalent of a slum, which is factory farms, where you have like millions of individuals crowded really close together. That means they’re breathing on each other more, they’re touching each other more, they’re being exposed to each other’s waste more. All of that creates opportunities for pathogens to spread between them.
Beyond the ways we live, and our animals live, are there other things we’re doing that make us more vulnerable?
Since 1918, of course, we’re traveling around, right? We’re bringing all this stuff everywhere we go. So you have an outbreak in some little town, in some remote area. Well, it doesn’t take very long for someone to pick that up, get on an airplane, and carry it around to a dozen countries at once.
The other thing that I find particularly alarming is the rise in xenophobia, and we saw this from the beginning with pandemics in the 18th and 19th centuries—that cholera would break out, and people, instead of looking for the true cause, which was really kind of hiding in plain sight, people blamed the Irish, people blamed the Muslims, people blamed poor people, they blamed alcoholics, and that kind of scapegoating really prevented people from actually adequately addressing the epidemic. It forces people to go underground so they’re ashamed. They don’t want to seek out help, and so you’re letting that pathogen spread unimpeded.
That kind of scapegoating is really dangerous. I think that it’s related to the growing number of outbreaks we do have now. I don’t think it’s unrelated. We have the growing threat of emerging pathogens. We also have this growing phenomenon of xenophobia where you see in the EU and the U.S., migrants, refugees are facing closed borders.
At the same time, since 1918, all of the ways in which we’re connected that make us more vulnerable to epidemics spreading between us also gives us a lot of strength, right? Because pathogens can spread really quickly, but information can also spread really quickly, and information is our biggest weapon against these things. If we know how a pathogen spreads, if we know its mode of transmission, then we can change our behavior.
As you say, that’s a lot of factors that could, put together, create some massive problems. Are we doing enough to prepare for future outbreaks?
I mean, the thing is, once we have a pandemic, it’s already too late.
What we really need to do is stanch outbreaks before they start to spread, so it’s not so much [asking] Do we have enough hospital beds? once we have a major pandemic underway. That’s an important question, but by that time, we’re already going have a huge mortality, morbidity, all those things are going be pretty substantial because we’ve already allowed the epidemic to spread into a pandemic.
So what we need [is] surveillance, and we need to change our behaviors in a way that doesn’t allow pathogens to spread in the first place.
What kinds of key behaviors do we need to change?
Well, we don’t know. I mean, there’s microbes all over the world, right? And there’s a huge number of them that we just don’t even know they’re out there. So how do we find out which ones we need to stanch?
Some microbes are going to be spreading around, and it’s fine. They’re not going to cause any problem. But some of them could become pathogenic. How do we predict that? How do we know where to go to find those hotspots?
That’s something we can figure out now. We know what the conditions are that allow microbes to turn pathogenic. What are the opportunities that allow that to happen? There’s places where there’s a lot of crowding of people, a lot of slums, a lot factory farming, a lot of invasion of wildlife habitat, a lot of people coming and going like through the airport.
So you can look at all of those risk factors and figure out, well, where are the hotspots where it’s most likely that a pandemic-causing pathogen would emerge? We have this map of the world, and we know where the hotspots are, and so in those places we should be doing active surveillance.
What we do right now is passive surveillance. So, [we] wait for an outbreak to happen and then, “Oh! There’s a cluster of cases in some hospital somewhere. Maybe it’s an outbreak. Let’s go see.” Well, by then, the pathogen has already started to spread. People are already starting to infect other people, and that’s why you have a cluster of cases showing up at a hospital that you can see, and you can detect that.
But by then, arguably, our response is linear. Meanwhile, the pathogen’s already starting to spread exponentially, so there’s a certain disconnect. But if we surveil in hotspots for pathogens, microbes that might be turning into pathogens, and if we alter the conditions that allow them to do that, then we can prevent them from spreading in the first place. So we kind of cut off the curve before it starts to grow.
Disease surveillance has improved a lot, but at the same time, there are the existence of these kind of data deserts around the world, particularly in developing countries where there’s not good data. Is there any way to kind of address those sorts of data deserts?
We have a lot of surveillance in places where it’s easy for us to do surveillance, but we don’t have a lot in the places where it’s hard to do it. This goes back to the role of international cooperation and trust: The erosion of that is a huge, huge obstacle, and we need to engage in the global economy and in international relations that build trust between nations so that we can do this work. And not every country has the capacity to do it, but we do, and we should be able to send our people and our resources into places so that we can build up that surveillance capacity.
And that’s something that I feel like we’re going in the wrong direction with the current administration’s attitude toward international relations.
What are the biggest barriers to establishing that trust and cooperation?
Right now, we have political leaders who are actively undermining trust in our institutions, actively undermining trust in science. The overriding fear I have today is about the breakdown in trust in our news media, that we have leaders who are actively undermining public trust in our information-gathering sources, and in our scientific leaders, and our scientific agencies.
Beyond all the other things that kind atomize us and make us distrust each other, at least we should have leadership that is saying, “Yes, trust your public health authorities. Yes, trust your reputable news sources.” Because when an epidemic happens, that’s exactly what we’re going to need. We’re going to need information we can trust from people who know what they’re talking about.
A lot of your work has looked at past outbreaks in order to predict and inform what may happen in the future and how we should respond to that. So if you had to crystallize a couple of key things that you think we can learn from the past that we should use as we’re moving into the future, what would those things be?
We prevent outbreaks every day by doing things like protecting the safety of our water, the cleanliness of our air, ensuring that our schools are safe, our workplaces are safe. The tragedy of public health is when it’s successful, nobody notices. Their greatest success is nothing happens. But we need to really make that obvious because I think today in the current climate, that kind of work is becoming very much marginalized, and it’s so important.
In the larger picture, we need to do things like changing the underlying conditions that cause pandemics in the first place. We can do things like restore wild habitats so that the microbes that live inside animals stay inside animals instead of crossing over into our bodies and adapting to our bodies.
We can do things like protect the health for the most vulnerable people among us. They are the people who are on the front lines of new diseases. So whether that’s animals who live in factory farms or refugees who are being deprived of asylum, or people who live in slums, anyone else whose health is being damaged by being deprived of their human rights—our health depends on their good health.
We can’t escape all infections. Having infectious diseases and living with microbes is part of living on this planet—and really, microbes were here first.
Outbreaks are inevitable, as [epidemiologist] Larry Brilliant put it, but pandemics are really optional.
This piece originally misstated the date of Future Tense’s event on the 100th anniversary of the 1918 influenza pandemic. It was Oct. 25, not Oct. 26.