Enlarge /. Scientists around the world are not only working to eradicate the current COVID-19 pandemic, but they're also trying to prevent an even worse outbreak in the future.
As much damage as the current coronavirus pandemic has done to the world as a whole – over 230,000 American citizens alone and nearly 1.2 million people worldwide have been killed to date – scientists know that there are other viruses lurking out there, one of which could be as contagious as it is COVID-19, but much more deadly. And they know we need to be prepared for such an outbreak.
That is the central message of Virus Hunters, a new documentary that premieres tonight on the National Geographic channel. The documentary follows award-winning ABC News foreign correspondent James Longman and Harvard ecologist and epidemiologist Chris Golden as they travel to hot spots around the world: Liberia, Thailand, Turkey and (yes) the US. It is a companion piece to a special edition of National Geographic magazine published in mid-October and dedicated to COVID-19.
As a National Geographic Fellow, Golden's interest in studying the effects of environmental change on human health dates back to childhood when he took nature walks with his mother. "I've seen her react to nature, this connection between mental health and nature, and I've followed this throughout my educational experience," he told Ars. After graduating from Harvard with a bachelor's degree, his own major a mix of courses in ecology, medical anthropology, and developmental studies, he received his PhD in epidemiology and ecology from the University of California at Berkeley.
Golden's lifelong obsession with Madagascar – "It all started with a National Geographic problem with lemurs on the cover" – led this region to become a central focus of his research and the motivation for the establishment of the nonprofit health and environmental research in Madagascar (MAHERY ) represented. When I lived with local communities, "I began to see the forest through their eyes," he said. "I realized that there is such a strong link between the integrity and health of the environment and the health of local communities." We sat down with Golden to learn more about his experience filming Virus Hunters – no less in the midst of a global pandemic.
Ars: Given the current COVID-19 pandemic, this is a particularly timely documentary special, but epidemiologists and other scientists like you have been warning of such spillover events for a long time.
Golden: That is absolutely correct. For decades, researchers have been at the forefront of research who have really invested in characterizing and chronicling all types of viruses, bacteria, and pathogens found in wildlife communities because they know these are the very types of things that could be spilled over into human populations. COVID-19 is no surprise, because that's how SARS, MERS, HIV, Ebola, and swine flu began. This type of pathogen transmission mechanism is nothing new. Even novel corona viruses are things that the Department of Defense and USDA in the United States have warned about as a threat to national security. It is really just a failure of action and preparation on our part because we know these threats exist.
Enlarge /. Harvard University ecologist and epidemiologist Chris Golden.
Ars: What was it like to make a documentary about deadly viruses during an actual global pandemic?
Golden: In the beginning it was very uncomfortable. I mean, I had hardly left my apartment to go down the street to the grocery store when I went to film this. Travel is a risk factor, although I don't think that is the biggest risk factor that we face here in the US. When we got to these places there were so many better protocols. As an example, we arrived in Liberia and everyone who got off the plane was temperature checked. Everyone wore a mask, there were hand-washing stations outside every building across the city, and all public health recommendations were met with tremendous compliance. This was one of the reasons they have had fewer than 200 cases in their country since the pandemic started: they started acting in late January. Because of their tragic past experiences with Ebola, they knew they were taking it seriously and they acted appropriately.
Ars: I was impressed by how many viruses with spillover potential come from bats in particular. Why are bats so important vectors?
Golden: There are really two factors. For one, there are just over 6,000 species of mammals worldwide, a quarter of which are bat species. Even from a statistical likelihood perspective, these viruses are more likely to originate from bats than any other animal because there are more bat species than many other broad animal species. Second, from a physiological and evolutionary point of view, bats are the only mammals that have developed a flight, and through this evolutionary process they have also developed really interesting immune systems, which in many cases are resistant to viruses. So this allows viruses to replicate in their own bodies and allows viruses to overflow without actually damaging them.
Because of the way they settle, and because of the way they live, their disease dynamics are very easy to spread in their own colonies. You can then make modifications or even mutations of viruses or diseases within a bat colony. Bats are also unique from an ecological and behavioral point of view. They are not animals that live exclusively in a forest or in remote areas. They have adapted very well to life in the city, life in barns and life in agricultural fields. And so there is a lot of human interface there. It makes a virus more likely to jump from bats to humans.
Ars: Was there anything that particularly surprised you on your travels?
Golden: One of the most surprising days for me was the day we visited the bush meat market in Monrovia, Liberia. This is a completely different system than the work I do in Madagascar. I've been there for 20 years. There really is no wildlife market in this country, and if you go to Monrovia and see this incredibly urban area flooded with meat from all other parts of the country, you will see all the vendors selling primates or deer or various forms of ungulates, Offering porcupine and cane rats – It was mind blowing to see the level of biodiversity, the demand from people who really wanted to eat this, and all of this in urban markets.
/. Jim Desmond, a disease and wildlife interventionist, is another scientist on Virus Hunters.
Ars: As I looked at this segment, I thought about how human behavior and ingrained cultural traditions – even those born out of necessity – can make it more difficult to control the spread of deadly viruses. How do you address such variables?
Golden: I think this question is really important, but it has a nuanced answer. In many regions of the world, these types of markets play an important role in food security. If they are dissolved or banned, it will have serious implications for the health and well-being of the local people, both economically and nutritionally. They are driven into these activities out of poverty, not because it is a luxury food item or because they are trying to make money. So if you give up the bushmeat hunt hard in this place, it has serious health consequences that can really pale a zoonosis when compared to the number of people who get sick or die from diet-related effects. However, there are many places where it is driven by luxury goods and economic demand. In that case, you could prohibit (such activities) without the same ethical consequences.
Ars: In the last section, you visit Wisconsin and speak to a deer hunter, among other things, about the likelihood of such diseases occurring in the US. There is a tendency, particularly among Americans, to assume that this risk is limited to overseas.
Golden: The decision to include this segment really depends on the fact that these viruses don't have to show up in remote or exotic locations. They could certainly happen right here on our own soil. If you look at the 1918 flu, the best possible guess where it came from is actually in Kansas. It only takes one instance of an animal virus that spreads to humans to begin. The entire deer segment was fascinating to me. It's a part of America that I haven't been allowed to visit often.
In Wisconsin, they kill over 400,000 deer each year. That one hunter we interviewed said he gets about six deer a year there – maybe 50 pounds of meat from each, with no guts, bones and so on. That's 300 pounds of meat, a pound of deer a day for his family. This is an important contribution to his food system. It really reflects a lot of the work I do in Madagascar in an almost bizarre way. It's this cultural connection, this food connection with the animal world. The disease we were looking at was not necessarily one that we were very concerned about for zoonotic transmission, but "bush meat" doesn't just happen elsewhere. Our own country has a huge market and a strong hunting tradition.
Ars: The main message from Virus Hunters is that COVID-19, bad as it is, is acting as a wake-up call. There could also be contagious, far more deadly viruses lurking that could spill over into human populations. Are you optimistic about the future or does it seem rather bleak from your point of view?
Golden: I think that you have to remain hopeful in my field, otherwise you will get depressed. In the field of conservation biology, you write these obituaries for so many natural systems, pristine systems, and it gets depressing at times. I really try to hope that events like this can be transformative and that we can align our society around the things that are important, that we can focus on the health of the planet and the health of people. And that we can use technology and research to drive this reorientation.
Virus Hunters will air on Sunday, November 1, 2020 at 9:00 p.m. to 8:00 p.m. on the National Geographic Channel.