How It All Started

hold the clues to stopping the next one. Scientists have learned that the new coronavirus shares of its genetic makeup with the virus previously detected in a kind of bat known as the horseshoe bat from the Yu Non province in China. It turns out these bats are viralogical treasure troves, so many of the infectious agents we worry most about coexist invert dual harmony with these nocturnal creatures. Bloomberg Senior editor Jason Gale takes us back to the mid nineteen nineties.

We're a surprise finding by scientists in Australia led to the emergence of the Batpack, a group of researchers who not only discovered a whole genus of dangerous viruses, but found what could be the precursor of the novel coronavirus. They're also laying the groundwork for potential treatments. Here's Jason. The story of bats and viruses can be traced to

an Australian veterinarian, Dr Hume Field. The son of a policeman, Hume grew up in various parts of the northeastern state of Queensland, where he developed a fascination for Australia's native fauna. I've always had an interest in animals, and I guess growing up as a kid, I can remember my parents saying our human lives animals. He's going to be a vet And this was really a bit of a throwaway line because nobody in our family had ever been to university,

led alone to a five year vetinry course. But nonetheless the sort of seed took hold, I guess, at least with me. When I caught up with him, he was in his home office in a leafy coastal area southeast of Brisbane. You could hear chattering wildlife and vocal pets,

as well as drought breaking rain. Hu graduated from the University of Queensland in six He worked for a couple of years in a small animal practice, but his interest in wildlife led him to pursue further study in the evenings, first in environmental science than a doctorate in the mid It allowed him to combine his love of native animals with emerging diseases at a time when the state's agricultural authorities, we're trying to figure out the source of a deadly

horsed disease. It was a virus that infected twenty race horses stable in the Brisbane suburb of hend. It's thought to have started when a mare called Drama Series was brought to the stables after she had been grazing in a field at Cannon Hill, on the other side of the Brisbane River. Drama Series died two days later, and subsequently all of the other horses fell ill. Thirteen of them died. What was especially alarming about this disease was

that it crossed the species barrier. A trainer and another person tending to the horses became ill with a flu like illness within days of Drama Series death. The stable hand recovered, but the trainer died of respiratory and kidney failure. The virus was eventually isolated and named Hendra virus after the suburb where it was found. Hume was asked to help determine how drama series might have caught the virus. He went searching the paddock where she had been grazing

and presumably had become infected. He caught rodents, possums, feral cats and reptiles and tested them for hendravirus. When the results came back negative, he went searching for clues. By the people rescuing vulnerable wildlife here in Australia, they're sometimes referred to as wildlife carries. So when we subsequently broadened our search and started using wildlife cares as I as a conduit if you like, to be able to collect samples from sick and injured animals that were in their care.

And it was in that process, so again quite serendipulous that we actually sample. We were sampling kangaroos, we were sampling parsons, we were sampling the usual things, ducks, the whole range of things that would come into wildlife cares. And there were flying foxes. When you sample some flying foxes. This was over a period of months and lo and behold, we found antibodies to handra virus and some flying foxes.

So we looked at some more flying foxes, and then we looked at some flying foxes in captive populace and the zoos et cetera. And to how we identified flying foxes as being at that stage are possible rest of while then we went on to do further studies eventually detected an isolated virus etcetera, etcetera. And so now flying foxes or at least a couple of species of flying foxes in Australia are recognized as the primary reservoir hosts

of hendrovirus. Flying foxes aren't actually foxes. There are large fruit eating bat with a kind of fox like face and expression. They weigh up to a couple of pounds and their wings can span more than three ft. The finding of hendrovirus in bats was important not just because it helped identify the pathway by which horses and people were being infected. It also made scientists alert to other

viruses bats could potentially carry. About a year after humid the discovery of hendravirus and flying foxes, another opportunity to explore the ecology of viruses and bats presented itself, this time in Malaysia, where pigs and pig farmers were getting sick. By mid more than two hundred and sixty five people had fallen ill with encephalitis or inflammation of the brain. Of those cases were fatal. There were also eleven cases of either encephalitis or respiratory illness, including one death. In

neighboring Singapore, scientists found the viral source. It was named neiper virus, which had turned out was from the same

family as hendra virus. Hume was asked to help investigate the source and wanted someone who was who might be able to guide and work with him to find out the natural reservoive but so none of we knew about hender and a bat stand immediately focused not exclusively, but was certainly focused on flying foxes in Malasia, and it wasn't too long before we found the evidence of of nepavirus in species of flying fox there, just as hendra

virus did. The discovery of NIPA underscored their risks that emerge at the interface of wildlife, farm, animals and humans. Professor Trevor Drew is the director of the Australian Animal Health Laboratory at Geelong, just outside of Melbourne. It's carried out key research on both Hendra and Niper viruses. According to Trevor, the emergence of Hendra and then Niper identified the ways in which batborn viruses can spill over it

and infect other species. And Nipper virus was a disease also of fruit bats in Malaysia initially, and that virus got into pigs because the they were starting to put pig farms into more forested areas, and the feces from the bats got into the pig styes and was thought to have infected the pigs that way, and it killed hundreds of pigs, if not thousands of pigs. Nipper isn't

just confined to Malaysia over the past decade. It's caused outbreaks in India and Bangladesh that have killed dozens of people.

We also now as also know from incidents in Bangladesh of outbreaks of NIPA virus that you don't need the pick that the that the bat can actually also infect humans directly via drinking out of vessels of palm sap that are put onto the tree to to harvest the palm sap, and people drink this palm sap, but so does the bat, and they will come down and the saliva from the bat can contaminate the palm sap and

infect the human directly. So we know that that that is one incident, but certainly in Malaysia now they're very very careful not to have pig farms near bat roosts, and even more dramatic outbreak occurred just a few years later. Severe acute respiratory syndrome or SARS emerged in southern China in two thousand and two. It's a deadly a cousin of COVID nineteen. They're quickly spread across the world. Hum

Field was usked to help investigate its source. And because of our experience with bats and hand virus and neatle virus, and growing awareness that there seemed to be something special about bats and these spillover viruses, then we hypothesize that bats may play a role in the the origins of stars,

and so we went down that track. It's interesting to reflect on the significance of the discovery of species of bats and flying foxes as the natural reservoir of hendra virus, because really that finding, I think has potentially colored the identification of bats or you know, sort of underlying the identification of various species of bats being associated with this suite of other emerging diseases that we're seeing over time.

If we have the group that Hume just referred to also includes a bowl of viruses and lists of virus which causes rabies, as well as a number of coronaviruses, including stars and most likely the one responsible for the COVID nineteen pandemic. So what is it about bats that makes them such great virus vectors. That's a quite unique if you think about it in terms of them being

a mammal that can fly. So so bats are mammals, they produce milk, they cyclely young, they but they've got this amazing evolutionary adaptation or ability to be able to fly so highly mobile. They also typically live in large populations, colonies roost, whether it's the big fruit bats or flying foxes, whether it's small microbats in caves, and typically these groups have mixed species as well. Um they're relatively long lived

animals as as a taxa. You know, flying fox are certainly recorded I think in captivity to live well into twenties. Certainly wouldn't live that long in nature, but certainly, you know, they live for years, so all of these factors are very attractive for mammalian virus survival and dissemination, if you like.

According to Hume, bats have evolved and adapted to coexist with the viruses that infect them, and so the thinking was that, well, you know, these are just viruses of bats, and the bats are used to them because they've evolved with them, and that's why the bats don't get sick with these viruses. But if they spill into other naive, immunologically naive species, then they have a dramatic, typically a

dramatic and often fatal infection. But more recent people have dug a bit further to try to understand if there isn't doing something else going on with bats, and it seems that there isn't. Hume now works as a science and policy adviser with the Eco Health Alliance. It's a New York based NGO that works to protect wildlife and public health from the emergence of disease. Spill over events

are becoming more risky. Bats, as we heard, are coming into closer contact with farm animals, but they're also coming into closer contact with humans. A key reason for that is that bats are losing their habitat. Critically, they're losing their natural food source. What you're hearing is the sound of gray headed flying foxes roosting. It's dusk and I'm sitting on a grassy bank of the Torrens River in

the center of Adelaide, the capital of South Australia. I'm literally a stone throw from the University of Adelaide, my Alma Marter behind me, and the Adelaide Zoo on the other side of the river. This is a popular place for the twenty thousand bats hanging upside down from the eucalyptus trees above me. It's a familiar place for Dr Mark Ship, Australia's chief ventinarian, who is based in Canberra but also grew up in South Australia. Mark is the

president of the World Organization for Animal Health. He told me that bats have taken up residency in Adelaide and

other urban centers, but not by choice. Yes, almost every city in Australia now has a resident roost of flying foxes, and the fruiting and the flowering trees that these bats normally feed on have been largely removed from rural Australia, and so they've been forced into urban centers and suburban parkland where there is some flowering trees and some fruiting trees, but these are not the preferred diet of the flying

foxes and they're putting those flying foxes under stress. We've seen a number of incidents in Australia over recent years with large scale mortalities of flying foxes due to heat events. Here in Canberra we had a large hail storm event which killed over three hundred flying foxes. It reflects that their their in centers where they would normally not be present, and that they're under stress when they're in those centers.

There's another concern with mats roosting places like this where horses are being kept less than a mile from here. For us, that the concern is that where we have parkland, we often have horses. And we know that flying foxes can transmit hendra virus two horses, and that those horses in turn can transmit that virus to humans, and and that's a fatal ease of both horses and of humans.

And then and then that there is the risk that the bats themselves will will transmit directly to human populations, and there are a number of coronaviruses and other viruses that bats carry and can transmit to the human population, but there are other consequences of the loss of that habitat. While these animals can carry some pretty nasty viruses, they perform functions vital for the Australian ecosystem. They play very important roles in terms of insect control, of pollination and

of seed dispersal. The role that they play in keeping down insect numbers which and and insects can transmit disease, particularly in Northern Australia, is very important. And then that the role that they play in pollinating plants as they move between plants and then dispersing see it's where they eat fruits and disperse the sards so that those plants become established in other areas is very important and is a role that no other participant in the ecosystem can ploy.

In the mammalian world, lifespan is generally proportional to body size and metabolic rate. That's defined both these rules. One bat species weighing just seven grams or a quarter of

an ounce, can live for more than forty years. It's one of a number of quirks of these critics, Professor Linda Wang has been unlocking the secrets of bats since the nine He was the scientist who isolated and characterized hendra virus and identified its viralogical cousin neiper Actually it was Lindfa who named the genus to which they both belong, hennepervirus. Back then he was working at the Australian Animal Health

Laboratory just outs out of Melbourne. He now heads the Emerging Infectious Diseases Program at Singapore's Duke and US Medical School. For the past thirteen years, he's devoted his career to studying bat biology and bat immunology, particularly its defense against viruses. He's brought a number of researchers along with him in Australia, Singapore and now China, where he was born and did his undergrad degree in scientific Circles. Lympha is sometimes known

as the Batman. People give me the nickname of Batman that I tried to cut them, that I actually don't started bad bat. Morris Lympha serves on the World Health Organization's Emergency Committee, advising the Director General on the current

COVID nineteen pandemic. It's a reflection of the knowledge he in his twenty person lab have amassed on these animals, and we have been focusing on the question of why that's, why that's are so different, why they can carry so many whiles and themselves do not get sick, and why that's lives so long, consider they're living in my moments, and also the strap they have during fly and also the pastern and they're exposed is much much more than

a non flying mammal. It turns out that the immune system of these flying mammals is different to that of terrestrial mammals. Bat's react to infections at an earlier stage, arresting them before they cause any disease. That enables bats to avoid the damaging inflammatory immune response. Other mammals, including humans, often mount in response to virulent infections. So our current working hypothesis is that that's have a much better the Torrents.

Pathologists studying COVID nineteen and other pathogenic viruses have observed that when the body initially recognizes an infection, various white blood cells that consume pathogens and help heal damage tissue act as first responders. In some severe infections, the body's effort to heal itself maybe two robust, leading to the destruction of not just virus infected cells, but healthy tissue.

It's that inflammatory response that ends up being deadly. Bats don't suffer the same fate that can defend themselves launch this inflammation, but they don't go over. Okay. So this is a very big area of research, and I think we human can live Lympha says he's convinced bats offer important insights into the regulation of the immune system that may inform ways the human body can better tackle COVID

nineteen and other viral diseases. So my slogan now is my study is basically learning from that that have so much of the teachers For one thing, lymph is intrigued that species of that that way is just seven grams, has a heart that beats more than one thousand times per minute during flight. It flies for five to eight hours daily and can live for forty three years. This is all down with the same heart without any medication, with any in the hygiene. You imagine that, right, It's incredible.

It's little wondered that Lindfa is working with cardiologists who study the heart muscles of bats just one of a number of medical disciplines he's recruited into his backpack have been able to mobilize, not in passion disease to people, genomics, people, immunologists and the case of bologists and now cardiologists are collaboys. Need just started back. My personal dream you have enough money,

is to statue a bad institute. I think that we have lots to learn from back that can help us identify what viruses of pandemic potential are lurking in nature, as well as ways we might be able to mitigate their threat. They're just one example of how humans are profoundly affected by what happens in global ecosystems. To anticipate, prevent, and respond to disease threats like COVID nineteen means taking an increasingly why right angled look at the natural world.

And that's it for this special episode of the Prognosis Daily Edition. For more on the pandemic from our bureaus around the world, visit Bloomberg dot com slash Coronavirus, and if you like the podcast, please take a moment to rate us and leave us a review on Apple Podcasts or Spotify. It helps more listeners find our global reporting. The Prognosis Daily edition is hosted by Me Laura Carlson. The show was produced by Me. Top foreheads Jordan Gaspore

and Magnus Henriksson. Reporting by Jason Gale. Original music by Leo sidran Our editors are Francesca Levi and Rick Shine. Francesco Levi is Bloomberg's head of podcasts. Thanks for listening.