“Not If, But When”: David Quammen on Why the Pandemic Was Inevitable
David Quammen’s 2012 book Spillover: Animal Infections and the Next Human Pandemic describes how and why zoonotic diseases, those passing from animals to humans, occur. The stories he tells — of Hendra, Ebola, HIV, malaria, Q fever, simian foamy virus, Lyme disease, Marburg, swine flu, avian flu, SARS, and many others — show how environmental disruption can lead to outbreaks, some of which have all the qualities needed to go global. Columbia Journalism School’s M.A. science journalism class spoke with Quammen last week about zoonotic disease and the current pandemic. The Q & A that follows has been edited for concision and clarity.
— Muriel Alarcón, Leo De Luca, Sarah Hurtes, Alison Kentish, Sofia Moutinho, Aayushi Pratap, Ellie Shechet, and Marguerite Holloway
Question: Did you know when you heard about this coronavirus in December that it was going to be a pandemic?
David Quammen: As soon as I heard the words “market, China and coronavirus,” I knew that this could be a pandemic and started being seriously concerned about it. I knew from scientists having told me 10 years ago that coronaviruses stand at the top of the watch list because they evolve quickly. They live in a lot of bats and sometimes they get pulled into markets in places such as China. With SARS, it was southern China; with this one, it was central China. I was already among those waiting: What will be the next big one? Not if, but when.
Q: What are the parallels that you see now, looking back at SARS?
DQ: The first important parallel is that the SARS virus was a coronavirus. And it was an outbreak that was so scary to the professionals that some of them who had worked on Ebola found SARS much scarier. Coronaviruses evolve especially quickly. They have a high mutation rate and therefore there is a lot of variation; the virus particles are competing against one another for access to the infected person’s cells. And so what do you have? You have evolution by natural selection. You have Darwin 1.0. So that’s what you have with coronaviruses: fast-evolving viruses, meaning they can adapt well to new hosts and adapt to transmission from one host to another. The SARS scientists I talked with said: “Beware of coronaviruses: coronaviruses are one of the groups that are at the top of the watchlist.”
The SARS virus also rode airplanes well. People didn’t get too sick before they were showing symptoms. Ebola makes people very sick very fast and that’s just one of the reasons why Ebola hasn’t ridden airplanes very much. There are other reasons too: it tends to strike poor people in remote African villages, who don’t have access to airplanes. This coronavirus and the SARS virus ride airplanes well. SARS got on airplanes in Hong Kong and rode to Toronto and Singapore and Bangkok and Hanoi and Beijing. Likewise, this virus has ridden airplanes quite proficiently.
Those are a couple of similarities, but there are differences. SARS had almost 10 percent case fatality rate. This is running at about 2 percent to 3 percent, except in Italy where it’s now at about 7 percent, partly because their health system is overwhelmed.
Q: Is there one factor that would explain why this new coronavirus spread so much and became this pandemic, while SARS, which had a higher fatality rate didn’t end up becoming this crazy pandemic we’re living now?
DQ: I don’t know exactly what the answer is. I think that probably part of the answer is that, like SARS, this has some super-spreaders, people who spread to many more than the average secondary cases do. I think that this virus is probably even more effective than the SARS virus at silent spread.
The other thing with SARS that was important was that by lucky chance, the places that it spread to from Hong Kong by airplane were places that had very good medical systems and very strong governments. They had control, as well as medical preparedness. Singapore: a very controlled place. Beijing. Hanoi. Controlling governments, centralized governments or authoritarian governments, depending on what word you want to use. Toronto. Not an authoritarian government, but a very strong medical system and a strong government. SARS did not burn out at 8,000 cases and 774 fatalities. It was stopped by really good fast science, good fast strong public health measures, and luck.
Q: You talk in the book about two things happening together: ecological destruction and the failure of the medical system to be able to respond or be prepared. Do you think COVID-19 is going to bring greater environmental awareness?
DQ: I’m trying to say to as many people as possible that this is not something that’s happening to us. This event is part of a pattern of events that reflect things that we are doing. We are disturbing the natural world more than ever before because there are 7.7 billion of us. We’re very hungry for resources, not just food. We’re hungry for energy. We’re hungry for minerals. We travel a lot.
Even if you don’t eat wildlife that comes from Chinese markets, or bats or penguins or whatever, if you’re a consumer, then you’re part of this problem. If you have a cell phone, if you have a laptop, then you are a consumer of the mineral coltan, which is necessary to make a certain kind of capacitor. Where is coltan acquired? It’s mined in the southeastern corner of Democratic Republic of the Congo in an area adjacent to rich rainforest with lowland gorillas, Eastern lowland gorillas, and a lot of kinds of bats and a lot of other creatures. And what do those workers eat who work in those mines? They probably eat bushmeat because there’s nothing else for them to eat. So that gives you some responsibility for this whole phenomenon of spillover from bats or any other kind of animals into humans. You need to understand that you have bought into this situation.
Q: Can you talk about how veterinary science and the medical sciences are increasingly coming together?
DQ: This is a whole new field. Some people give it the label “One Health,” meaning, animal health, human health, it’s all one. Animal diseases, human diseases, these kinds of things show us that those can be the same diseases, same pathogens. It’s an important new field of science. These disease detectives, they’re very, very interesting, admirable, courageous people. They tend to be cross trained. They tend to be people who have, for instance, a PhD in ecology, and then also maybe a Master’s in Public Health, or a PhD in ecology, maybe an MPH and also a medical degree or a veterinary degree, or they might be, they might have a veterinary degree and a PhD in biology. This mix of training makes them very valuable and allows them to do what they do.
Q: Can we expect that if the wild markets ended we could avoid the next pandemic?
DQ: The end of the wild markets in China would help a lot. But there are still lots of other ways where these spillovers can happen — lots of other places where they can happen. I mentioned the southeastern corner of fDemocratic Republic of Congo, where they’re mining coltan. So those things are going on. Energy development in tropical forests is going on. It’s not unique to China and it’s not unique to the live markets where bats and other wild animals are caught and brought in. Certainly right now it’s the most conspicuous starting point and it’s probably also one of the most dangerous kinds of starting point — one of the highest probability situations to produce spillovers like this — but there are lots of others around the world, so shutting down those markets is not going to be the end of zoonotic pandemics.
Q: Because of what we are seeing and the scale of what we are seeing, do you think we will do what is necessary to prevent the next one?
DQ: I am hopeful in that sense that this is already bad enough that it will be hard to ignore after it is over. But the problem is that spending to prepare for the next one, to get excess hospital capacity and to get massive development of vaccine capacity and massive development of the ability to create new diagnostic tests quickly, all of that preparedness work is expensive, very expensive…not as expensive as this. But it is expensive. And it is spending money to prevent things that might or might not happen. That is a big part of what makes it difficult to persuade policy makers or the people who control the wheels of government to do that. They are spending a lot of money to prevent things that might not happen anyway.
Q: Should we expect to see more pandemics clustered more closely together than historically?
DQ: The people at EcoHealth Alliance have done a study based on an examination of a large number of these outbreaks, not pandemics, but dangerous zoonotic outbreaks that they found were two to four times more frequent in the last 50 years. It is very hard to know how to take that metric because people are paying more attention. But it is probable that these spillovers are happening more frequently now and therefore there is a chance that pandemics will happen more frequently too.
Q: Could you talk about how this is not the bats’ fault and what is so interesting about bats. Is it the down-regulation of the immune system because of flight?
DQ A lot of these diseases, these zoonotic diseases that pass from non-human animals into humans, come from bats. Bats are what are called the reservoir host, the kind of animal in which the particular virus lives sort of permanently, inconspicuously, chronically, without really causing disease or symptoms. Even though a number of these viruses come from bats, what is the solution? It is not to kill all the bats! Don’t kill the bats! It is not their fault. It happens because we come in contact with them. So the logical conclusion is, leave the bats the hell alone. And then these viruses will reside in them, and they will never become human viruses, and will never become a problem. We need bats. Bats contribute to our ecosystems. They play an important role. So don’t demonize bats.
But still there is a question: Why bats? Why do bats seem to be overly represented as the reservoir hosts of these emerging viruses? And there’s a couple of probable reasons. One is that bats are the most diverse order of mammals. One in every four species of mammal on the planet is a species of bat. They are extraordinarily diverse. Beyond that, bats can live a long time. They roost, many of the species, in dense aggregations. You talk about social distancing, it is not social distancing. So that is a situation where the bats can be passing a virus from one to another and circulating it in their population.
Finally, there is a hypothesis that scientists are starting to look at, which is that bats have immune systems that are less sensitive — that have been down-regulated, is the term. Bats are the only truly flying mammal, and flying puts a lot of stress on physiology, on metabolism. It is possible, and this is a hypothesis, that doing that causes stress in the bats that busts open cells and leaves what they call naked DNA floating around in their bodies and in their bloodstream. The bat immune system could react to that and attack it, which would be a form of autoimmune disease. But if the bats’ immune system has evolved to the point it is forgiving, is less sensitive, is able to ignore strange things floating around in the body, then the bat is not going to be suffering autoimmune disease. So maybe that is what happened and the consequence is their immune systems are more tolerant of viruses floating around.
Q: What kind of lessons should this pandemic give us in our relationship with the environment?
A: Well, it is a big reminder that first of all, humans are part of nature. We are connected to nature, we are not separate from it. A bat virus can become a human virus. Why is that? Well, because we are related to bats. We belong to the same class of animals, mammals. So that is a good reminder. That bats are our relatives. That we are part of the natural world.
