Speaker 1: Welcome to Prognosis. I'm Laura Carlson. It's day thirty one
Speaker 1: since coronavirus was declared a global pandemic. Today we're bringing
Speaker 1: you a special episode of the podcast. It's a close
Speaker 1: look at how the novel coronavirus lived before it entered
Speaker 1: humans and who it lived in bats. They are almost
Speaker 1: certainly the source of this pandemic, but they may also
Speaker 1: hold the clues to stopping the next one. Scientists have
Speaker 1: learned that the new coronavirus shares of its genetic makeup
Speaker 1: with the virus previously detected in a kind of bat
Speaker 1: known as the horseshoe bat from the Yu Non province
Speaker 1: in China. It turns out these bats are viralogical treasure troves,
Speaker 1: so many of the infectious agents we worry most about
Speaker 1: coexist invert dual harmony with these nocturnal creatures. Bloomberg Senior
Speaker 1: editor Jason Gale takes us back to the mid nineteen nineties.
Speaker 1: We're a surprise finding by scientists in Australia led to
Speaker 1: the emergence of the Batpack, a group of researchers who
Speaker 1: not only discovered a whole genus of dangerous viruses, but
Speaker 1: found what could be the precursor of the novel coronavirus.
Speaker 1: They're also laying the groundwork for potential treatments. Here's Jason.
Speaker 1: The story of bats and viruses can be traced to
Speaker 1: an Australian veterinarian, Dr Hume Field. The son of a policeman,
Speaker 1: Hume grew up in various parts of the northeastern state
Speaker 1: of Queensland, where he developed a fascination for Australia's native fauna.
Speaker 1: I've always had an interest in animals, and I guess
Speaker 1: growing up as a kid, I can remember my parents
Speaker 1: saying our human lives animals. He's going to be a
Speaker 1: vet And this was really a bit of a throwaway
Speaker 1: line because nobody in our family had ever been to university,
Speaker 1: led alone to a five year vetinry course. But nonetheless
Speaker 1: the sort of seed took hold, I guess, at least
Speaker 1: with me. When I caught up with him, he was
Speaker 1: in his home office in a leafy coastal area southeast
Speaker 1: of Brisbane. You could hear chattering wildlife and vocal pets,
Speaker 1: as well as drought breaking rain. Hu graduated from the
Speaker 1: University of Queensland in six He worked for a couple
Speaker 1: of years in a small animal practice, but his interest
Speaker 1: in wildlife led him to pursue further study in the evenings,
Speaker 1: first in environmental science than a doctorate in the mid
Speaker 1: It allowed him to combine his love of native animals
Speaker 1: with emerging diseases at a time when the state's agricultural authorities,
Speaker 1: we're trying to figure out the source of a deadly
Speaker 1: horsed disease. It was a virus that infected twenty race
Speaker 1: horses stable in the Brisbane suburb of hend. It's thought
Speaker 1: to have started when a mare called Drama Series was
Speaker 1: brought to the stables after she had been grazing in
Speaker 1: a field at Cannon Hill, on the other side of
Speaker 1: the Brisbane River. Drama Series died two days later, and
Speaker 1: subsequently all of the other horses fell ill. Thirteen of
Speaker 1: them died. What was especially alarming about this disease was
Speaker 1: that it crossed the species barrier. A trainer and another
Speaker 1: person tending to the horses became ill with a flu
Speaker 1: like illness within days of Drama Series death. The stable
Speaker 1: hand recovered, but the trainer died of respiratory and kidney failure.
Speaker 1: The virus was eventually isolated and named Hendra virus after
Speaker 1: the suburb where it was found. Hume was asked to
Speaker 1: help determine how drama series might have caught the virus.
Speaker 1: He went searching the paddock where she had been grazing
Speaker 1: and presumably had become infected. He caught rodents, possums, feral
Speaker 1: cats and reptiles and tested them for hendravirus. When the
Speaker 1: results came back negative, he went searching for clues. By
Speaker 1: the people rescuing vulnerable wildlife here in Australia, they're sometimes
Speaker 1: referred to as wildlife carries. So when we subsequently broadened
Speaker 1: our search and started using wildlife cares as I as
Speaker 1: a conduit if you like, to be able to collect
Speaker 1: samples from sick and injured animals that were in their care.
Speaker 1: And it was in that process, so again quite serendipulous
Speaker 1: that we actually sample. We were sampling kangaroos, we were
Speaker 1: sampling parsons, we were sampling the usual things, ducks, the
Speaker 1: whole range of things that would come into wildlife cares.
Speaker 1: And there were flying foxes. When you sample some flying foxes.
Speaker 1: This was over a period of months and lo and behold,
Speaker 1: we found antibodies to handra virus and some flying foxes.
Speaker 1: So we looked at some more flying foxes, and then
Speaker 1: we looked at some flying foxes in captive populace and
Speaker 1: the zoos et cetera. And to how we identified flying
Speaker 1: foxes as being at that stage are possible rest of
Speaker 1: while then we went on to do further studies eventually
Speaker 1: detected an isolated virus etcetera, etcetera. And so now flying
Speaker 1: foxes or at least a couple of species of flying
Speaker 1: foxes in Australia are recognized as the primary reservoir hosts
Speaker 1: of hendrovirus. Flying foxes aren't actually foxes. There are large
Speaker 1: fruit eating bat with a kind of fox like face
Speaker 1: and expression. They weigh up to a couple of pounds
Speaker 1: and their wings can span more than three ft. The
Speaker 1: finding of hendrovirus in bats was important not just because
Speaker 1: it helped identify the pathway by which horses and people
Speaker 1: were being infected. It also made scientists alert to other
Speaker 1: viruses bats could potentially carry. About a year after humid
Speaker 1: the discovery of hendravirus and flying foxes, another opportunity to
Speaker 1: explore the ecology of viruses and bats presented itself, this
Speaker 1: time in Malaysia, where pigs and pig farmers were getting sick.
Speaker 1: By mid more than two hundred and sixty five people
Speaker 1: had fallen ill with encephalitis or inflammation of the brain.
Speaker 1: Of those cases were fatal. There were also eleven cases
Speaker 1: of either encephalitis or respiratory illness, including one death. In
Speaker 1: neighboring Singapore, scientists found the viral source. It was named
Speaker 1: neiper virus, which had turned out was from the same
Speaker 1: family as hendra virus. Hume was asked to help investigate
Speaker 1: the source and wanted someone who was who might be
Speaker 1: able to guide and work with him to find out
Speaker 1: the natural reservoive but so none of we knew about
Speaker 1: hender and a bat stand immediately focused not exclusively, but
Speaker 1: was certainly focused on flying foxes in Malasia, and it
Speaker 1: wasn't too long before we found the evidence of of
Speaker 1: nepavirus in species of flying fox there, just as hendra
Speaker 1: virus did. The discovery of NIPA underscored their risks that
Speaker 1: emerge at the interface of wildlife, farm, animals and humans.
Speaker 1: Professor Trevor Drew is the director of the Australian Animal
Speaker 1: Health Laboratory at Geelong, just outside of Melbourne. It's carried
Speaker 1: out key research on both Hendra and Niper viruses. According
Speaker 1: to Trevor, the emergence of Hendra and then Niper identified
Speaker 1: the ways in which batborn viruses can spill over it
Speaker 1: and infect other species. And Nipper virus was a disease
Speaker 1: also of fruit bats in Malaysia initially, and that virus
Speaker 1: got into pigs because the they were starting to put
Speaker 1: pig farms into more forested areas, and the feces from
Speaker 1: the bats got into the pig styes and was thought
Speaker 1: to have infected the pigs that way, and it killed
Speaker 1: hundreds of pigs, if not thousands of pigs. Nipper isn't
Speaker 1: just confined to Malaysia over the past decade. It's caused
Speaker 1: outbreaks in India and Bangladesh that have killed dozens of people.
Speaker 1: We also now as also know from incidents in Bangladesh
Speaker 1: of outbreaks of NIPA virus that you don't need the
Speaker 1: pick that the that the bat can actually also infect
Speaker 1: humans directly via drinking out of vessels of palm sap
Speaker 1: that are put onto the tree to to harvest the
Speaker 1: palm sap, and people drink this palm sap, but so
Speaker 1: does the bat, and they will come down and the
Speaker 1: saliva from the bat can contaminate the palm sap and
Speaker 1: infect the human directly. So we know that that that
Speaker 1: is one incident, but certainly in Malaysia now they're very
Speaker 1: very careful not to have pig farms near bat roosts,
Speaker 1: and even more dramatic outbreak occurred just a few years later.
Speaker 1: Severe acute respiratory syndrome or SARS emerged in southern China
Speaker 1: in two thousand and two. It's a deadly a cousin
Speaker 1: of COVID nineteen. They're quickly spread across the world. Hum
Speaker 1: Field was usked to help investigate its source. And because
Speaker 1: of our experience with bats and hand virus and neatle virus,
Speaker 1: and growing awareness that there seemed to be something special
Speaker 1: about bats and these spillover viruses, then we hypothesize that
Speaker 1: bats may play a role in the the origins of stars,
Speaker 1: and so we went down that track. It's interesting to
Speaker 1: reflect on the significance of the discovery of species of
Speaker 1: bats and flying foxes as the natural reservoir of hendra virus,
Speaker 1: because really that finding, I think has potentially colored the
Speaker 1: identification of bats or you know, sort of underlying the
Speaker 1: identification of various species of bats being associated with this
Speaker 1: suite of other emerging diseases that we're seeing over time.
Speaker 1: If we have the group that Hume just referred to
Speaker 1: also includes a bowl of viruses and lists of virus
Speaker 1: which causes rabies, as well as a number of coronaviruses,
Speaker 1: including stars and most likely the one responsible for the
Speaker 1: COVID nineteen pandemic. So what is it about bats that
Speaker 1: makes them such great virus vectors. That's a quite unique
Speaker 1: if you think about it in terms of them being
Speaker 1: a mammal that can fly. So so bats are mammals,
Speaker 1: they produce milk, they cyclely young, they but they've got
Speaker 1: this amazing evolutionary adaptation or ability to be able to
Speaker 1: fly so highly mobile. They also typically live in large populations,
Speaker 1: colonies roost, whether it's the big fruit bats or flying foxes,
Speaker 1: whether it's small microbats in caves, and typically these groups
Speaker 1: have mixed species as well. Um they're relatively long lived
Speaker 1: animals as as a taxa. You know, flying fox are
Speaker 1: certainly recorded I think in captivity to live well into twenties.
Speaker 1: Certainly wouldn't live that long in nature, but certainly, you know,
Speaker 1: they live for years, so all of these factors are
Speaker 1: very attractive for mammalian virus survival and dissemination, if you like.
Speaker 1: According to Hume, bats have evolved and adapted to coexist
Speaker 1: with the viruses that infect them, and so the thinking
Speaker 1: was that, well, you know, these are just viruses of bats,
Speaker 1: and the bats are used to them because they've evolved
Speaker 1: with them, and that's why the bats don't get sick
Speaker 1: with these viruses. But if they spill into other naive,
Speaker 1: immunologically naive species, then they have a dramatic, typically a
Speaker 1: dramatic and often fatal infection. But more recent people have
Speaker 1: dug a bit further to try to understand if there
Speaker 1: isn't doing something else going on with bats, and it
Speaker 1: seems that there isn't. Hume now works as a science
Speaker 1: and policy adviser with the Eco Health Alliance. It's a
Speaker 1: New York based NGO that works to protect wildlife and
Speaker 1: public health from the emergence of disease. Spill over events
Speaker 1: are becoming more risky. Bats, as we heard, are coming
Speaker 1: into closer contact with farm animals, but they're also coming
Speaker 1: into closer contact with humans. A key reason for that
Speaker 1: is that bats are losing their habitat. Critically, they're losing
Speaker 1: their natural food source. What you're hearing is the sound
Speaker 1: of gray headed flying foxes roosting. It's dusk and I'm
Speaker 1: sitting on a grassy bank of the Torrens River in
Speaker 1: the center of Adelaide, the capital of South Australia. I'm
Speaker 1: literally a stone throw from the University of Adelaide, my
Speaker 1: Alma Marter behind me, and the Adelaide Zoo on the
Speaker 1: other side of the river. This is a popular place
Speaker 1: for the twenty thousand bats hanging upside down from the
Speaker 1: eucalyptus trees above me. It's a familiar place for Dr
Speaker 1: Mark Ship, Australia's chief ventinarian, who is based in Canberra
Speaker 1: but also grew up in South Australia. Mark is the
Speaker 1: president of the World Organization for Animal Health. He told
Speaker 1: me that bats have taken up residency in Adelaide and
Speaker 1: other urban centers, but not by choice. Yes, almost every
Speaker 1: city in Australia now has a resident roost of flying foxes,
Speaker 1: and the fruiting and the flowering trees that these bats
Speaker 1: normally feed on have been largely removed from rural Australia,
Speaker 1: and so they've been forced into urban centers and suburban
Speaker 1: parkland where there is some flowering trees and some fruiting trees,
Speaker 1: but these are not the preferred diet of the flying
Speaker 1: foxes and they're putting those flying foxes under stress. We've
Speaker 1: seen a number of incidents in Australia over recent years
Speaker 1: with large scale mortalities of flying foxes due to heat events.
Speaker 1: Here in Canberra we had a large hail storm event
Speaker 1: which killed over three hundred flying foxes. It reflects that
Speaker 1: their their in centers where they would normally not be present,
Speaker 1: and that they're under stress when they're in those centers.
Speaker 1: There's another concern with mats roosting places like this where
Speaker 1: horses are being kept less than a mile from here.
Speaker 1: For us, that the concern is that where we have parkland,
Speaker 1: we often have horses. And we know that flying foxes
Speaker 1: can transmit hendra virus two horses, and that those horses
Speaker 1: in turn can transmit that virus to humans, and and
Speaker 1: that's a fatal ease of both horses and of humans.
Speaker 1: And then and then that there is the risk that
Speaker 1: the bats themselves will will transmit directly to human populations,
Speaker 1: and there are a number of coronaviruses and other viruses
Speaker 1: that bats carry and can transmit to the human population,
Speaker 1: but there are other consequences of the loss of that habitat.
Speaker 1: While these animals can carry some pretty nasty viruses, they
Speaker 1: perform functions vital for the Australian ecosystem. They play very
Speaker 1: important roles in terms of insect control, of pollination and
Speaker 1: of seed dispersal. The role that they play in keeping
Speaker 1: down insect numbers which and and insects can transmit disease,
Speaker 1: particularly in Northern Australia, is very important. And then that
Speaker 1: the role that they play in pollinating plants as they
Speaker 1: move between plants and then dispersing see it's where they
Speaker 1: eat fruits and disperse the sards so that those plants
Speaker 1: become established in other areas is very important and is
Speaker 1: a role that no other participant in the ecosystem can ploy.
Speaker 1: In the mammalian world, lifespan is generally proportional to body
Speaker 1: size and metabolic rate. That's defined both these rules. One
Speaker 1: bat species weighing just seven grams or a quarter of
Speaker 1: an ounce, can live for more than forty years. It's
Speaker 1: one of a number of quirks of these critics, Professor
Speaker 1: Linda Wang has been unlocking the secrets of bats since
Speaker 1: the nine He was the scientist who isolated and characterized
Speaker 1: hendra virus and identified its viralogical cousin neiper Actually it
Speaker 1: was Lindfa who named the genus to which they both belong, hennepervirus.
Speaker 1: Back then he was working at the Australian Animal Health
Speaker 1: Laboratory just outs out of Melbourne. He now heads the
Speaker 1: Emerging Infectious Diseases Program at Singapore's Duke and US Medical School.
Speaker 1: For the past thirteen years, he's devoted his career to
Speaker 1: studying bat biology and bat immunology, particularly its defense against viruses.
Speaker 1: He's brought a number of researchers along with him in Australia,
Speaker 1: Singapore and now China, where he was born and did
Speaker 1: his undergrad degree in scientific Circles. Lympha is sometimes known
Speaker 1: as the Batman. People give me the nickname of Batman
Speaker 1: that I tried to cut them, that I actually don't
Speaker 1: started bad bat. Morris Lympha serves on the World Health
Speaker 1: Organization's Emergency Committee, advising the Director General on the current
Speaker 1: COVID nineteen pandemic. It's a reflection of the knowledge he
Speaker 1: in his twenty person lab have amassed on these animals,
Speaker 1: and we have been focusing on the question of why that's,
Speaker 1: why that's are so different, why they can carry so
Speaker 1: many whiles and themselves do not get sick, and why
Speaker 1: that's lives so long, consider they're living in my moments,
Speaker 1: and also the strap they have during fly and also
Speaker 1: the pastern and they're exposed is much much more than
Speaker 1: a non flying mammal. It turns out that the immune
Speaker 1: system of these flying mammals is different to that of
Speaker 1: terrestrial mammals. Bat's react to infections at an earlier stage,
Speaker 1: arresting them before they cause any disease. That enables bats
Speaker 1: to avoid the damaging inflammatory immune response. Other mammals, including humans,
Speaker 1: often mount in response to virulent infections. So our current
Speaker 1: working hypothesis is that that's have a much better the Torrents.
Speaker 1: Pathologists studying COVID nineteen and other pathogenic viruses have observed
Speaker 1: that when the body initially recognizes an infection, various white
Speaker 1: blood cells that consume pathogens and help heal damage tissue
Speaker 1: act as first responders. In some severe infections, the body's
Speaker 1: effort to heal itself maybe two robust, leading to the
Speaker 1: destruction of not just virus infected cells, but healthy tissue.
Speaker 1: It's that inflammatory response that ends up being deadly. Bats
Speaker 1: don't suffer the same fate that can defend themselves launch
Speaker 1: this inflammation, but they don't go over. Okay. So this
Speaker 1: is a very big area of research, and I think
Speaker 1: we human can live Lympha says he's convinced bats offer
Speaker 1: important insights into the regulation of the immune system that
Speaker 1: may inform ways the human body can better tackle COVID
Speaker 1: nineteen and other viral diseases. So my slogan now is
Speaker 1: my study is basically learning from that that have so
Speaker 1: much of the teachers For one thing, lymph is intrigued
Speaker 1: that species of that that way is just seven grams,
Speaker 1: has a heart that beats more than one thousand times
Speaker 1: per minute during flight. It flies for five to eight
Speaker 1: hours daily and can live for forty three years. This
Speaker 1: is all down with the same heart without any medication,
Speaker 1: with any in the hygiene. You imagine that, right, It's incredible.
Speaker 1: It's little wondered that Lindfa is working with cardiologists who
Speaker 1: study the heart muscles of bats just one of a
Speaker 1: number of medical disciplines he's recruited into his backpack have
Speaker 1: been able to mobilize, not in passion disease to people, genomics, people,
Speaker 1: immunologists and the case of bologists and now cardiologists are collaboys.
Speaker 1: Need just started back. My personal dream you have enough money,
Speaker 1: is to statue a bad institute. I think that we
Speaker 1: have lots to learn from back that can help us
Speaker 1: identify what viruses of pandemic potential are lurking in nature,
Speaker 1: as well as ways we might be able to mitigate
Speaker 1: their threat. They're just one example of how humans are
Speaker 1: profoundly affected by what happens in global ecosystems. To anticipate, prevent,
Speaker 1: and respond to disease threats like COVID nineteen means taking
Speaker 1: an increasingly why right angled look at the natural world.
Speaker 1: And that's it for this special episode of the Prognosis
Speaker 1: Daily Edition. For more on the pandemic from our bureaus
Speaker 1: around the world, visit Bloomberg dot com slash Coronavirus, and
Speaker 1: if you like the podcast, please take a moment to
Speaker 1: rate us and leave us a review on Apple Podcasts
Speaker 1: or Spotify. It helps more listeners find our global reporting.
Speaker 1: The Prognosis Daily edition is hosted by Me Laura Carlson.
Speaker 1: The show was produced by Me. Top foreheads Jordan Gaspore
Speaker 1: and Magnus Henriksson. Reporting by Jason Gale. Original music by
Speaker 1: Leo sidran Our editors are Francesca Levi and Rick Shine.
Speaker 1: Francesco Levi is Bloomberg's head of podcasts. Thanks for listening.