Speaker 1: Welcome to Prognosis. I'm Laura Carlson. It's day one and
Speaker 1: twenty four since coronavirus was declared a global pandemic. Today's
Speaker 1: main story. Much of what we know suggests the virus
Speaker 1: is transmitted through tiny droplets from infected people, but researchers
Speaker 1: are now looking at tiny air assaults that linger in
Speaker 1: the air and whether they too can infect us. But first,
Speaker 1: here's what happened in virus news today. The World Health
Speaker 1: Organization had a sobering message at a briefing this morning.
Speaker 1: COVID nineteen won't disappear quickly, and it's unrealistic to hang
Speaker 1: our hopes on a perfect vaccine emerging soon. You h
Speaker 1: Joe head tatris at Anam Gabrie Sus said strong government
Speaker 1: leadership was necessary and that fighting the virus is a
Speaker 1: long term commitment. In the US, the virus is making
Speaker 1: a comeback in states that thought they had already endured
Speaker 1: the worst of it. California, Louisiana, Michigan, and Washington State
Speaker 1: are seeing case counts climb again after months of declines.
Speaker 1: It's not just a matter of more testing, hospitalizations, and
Speaker 1: in some places, deaths are rising too. Experts say the
Speaker 1: diseases on the rise in these states for the same
Speaker 1: reasons it's breaking records in places like Florida. Those reasons
Speaker 1: include a population no longer willing to stay inside, Republicans
Speaker 1: who refuse face masks as a political statement, street protests
Speaker 1: over police violence, and young people convinced the virus won't
Speaker 1: seriously hurt them. Early in the pandemic, New York had
Speaker 1: one of the worst outbreaks in the US and took
Speaker 1: some of the strictest lockdown measures that has paid off.
Speaker 1: This weekend, New York City had its first day without
Speaker 1: a COVID nineteen death since the outbreak, But even there,
Speaker 1: officials are seeing a worrying trend. Cases are rising among
Speaker 1: people aged twenty nine. Today, Mayor build A Blasio said
Speaker 1: the city will work to educate young people on the
Speaker 1: importance of wearing masks and keeping socially distant. And now
Speaker 1: for today's main story, we're learning more about how stars
Speaker 1: cove two, the virus that causes COVID nineteen, is spread
Speaker 1: from person to person. For the most part, it happens
Speaker 1: when we're in close contact with an infected person who
Speaker 1: we met. Tiny liquid particles by coughing, sneezing, speaking, or singing.
Speaker 1: These droplets come out even when we just breathe. Normally,
Speaker 1: you get the virus by inhaling the droplets, having them
Speaker 1: travel into your ears or nose, or getting one stock
Speaker 1: on your hand which you then absentmindedly used to touch
Speaker 1: in orifice. But at a New Year's lunch in China,
Speaker 1: a group of people got sick in a way that
Speaker 1: suggested there might be another way you can get COVID nineteen,
Speaker 1: Bloomberg Senior editor Jason Gale reports on the latest worry
Speaker 1: that virus laden aerosols floating in gas clouds could infect us.
Speaker 1: In China, the holidays main mass migration. People travel across
Speaker 1: the country to catch up with relatives, enjoy reunion dinners,
Speaker 1: and hand out cash filled red envelopes to children. A
Speaker 1: family from Wuhan, the central Chinese city where the coronavirus emerged,
Speaker 1: was part of that mass movement. Back in January. This
Speaker 1: family of ten quarter train to the southern city of
Speaker 1: Guangzho the day before, having lunch in a crowded restaurant.
Speaker 1: It was the eve of the lunar New Year. What
Speaker 1: they didn't know at the time was that one of them,
Speaker 1: six year old art, was coming down with COVID nineteen.
Speaker 1: A few hours after leaving the restaurant, the retiree developed
Speaker 1: a fever and cough. It means she was probably at
Speaker 1: her most infectious when she squeezed into a seat at
Speaker 1: a round table at the back of the restaurant as
Speaker 1: the family enjoyed lunch and air conditioner blue air across
Speaker 1: the back of the room where they were seated. That
Speaker 1: was a few feet from two other families at neighboring tables. Importantly,
Speaker 1: their air conditioning unit on the wall facing the aren't
Speaker 1: incubating COVID was blowing air over all three tables, and
Speaker 1: it turns out that warm breeze and lunch were the
Speaker 1: only things these families shared. A week and a half later,
Speaker 1: on February five, nine more of the diners had come
Speaker 1: down with COVID nineteen, four members of the Wuhan family
Speaker 1: plus five members of the two other families, but none
Speaker 1: of the waiters or seventy three other patrons in the
Speaker 1: room contracted the disease, and neither did anyone back at
Speaker 1: the Guangzho Hotel. Whether the Wuhan family was staying researchers
Speaker 1: investigating the outbreak were in luck. There was a close
Speaker 1: circuit television camera in the restaurant, and the footage showed
Speaker 1: no close contact between each table's guests, aside from several
Speaker 1: seats being back to back. So to figure out how
Speaker 1: the virus spread over several meters, the researchers simulated the
Speaker 1: air flow across the three tables, and it pointed to
Speaker 1: what many scientists had feared. That is that the virus
Speaker 1: could be suspended and moved about in the ambient air
Speaker 1: long enough and far enough to cause multiple infections. That
Speaker 1: this could occur is no surprise for Professor Ben Cowling,
Speaker 1: head of epidemiology and bios Statistics at the University of
Speaker 1: Hong Kong, then assisted China in the early study of
Speaker 1: the coronavirus. Is transmission dynamics. When I hear that transmissions
Speaker 1: going on after prolong closed contact, it makes me think
Speaker 1: that aerosols are playing a role mostly at short range,
Speaker 1: but in rooms where there's poorer ventilation, people spend a
Speaker 1: longer period of time. You might see a little bit
Speaker 1: a long way to transmission. And we have seen outbreaks
Speaker 1: in coll centers. Enquired practices in restaurants and bars and nightclubs,
Speaker 1: and that's the kind of situations where where if their
Speaker 1: ventilation is not as good, you could see a bit
Speaker 1: of aerosols happening. The outbreak in the Guangho restaurant has
Speaker 1: become the touchstone in a global debate about how the
Speaker 1: coronavirus can spread in poorly ventilated spaces and the x
Speaker 1: your measures that may be required to halt it. At
Speaker 1: the heart of the controversy remained lingering questions about how
Speaker 1: often such airborne transmission occurs. After all, the gang incident
Speaker 1: shows a majority of diners in the restaurant remained healthy,
Speaker 1: and so did roughly half of the people at the
Speaker 1: table where the infected woman from Woohan was sitting, and
Speaker 1: at the tables on either side of hers. He's been
Speaker 1: calling again. Yes, So in Hong Kong, we've we've done
Speaker 1: a bit of that analysis. We've found that seventy of
Speaker 1: copy cases didn't pass infection to anyone else, and it
Speaker 1: was just a minority. It was a minority that caused
Speaker 1: on was transmission, and that's presumably a minority of cases
Speaker 1: are more contagious, and then among those, some of them
Speaker 1: have the potential to spread to lots of others, and
Speaker 1: so we have this super spreading phenomenon. And I think
Speaker 1: when there is super spreading going on, the most likely
Speaker 1: explanation for that is also aerosoul transmission. But that's not
Speaker 1: to scare everybody. That's just to state that the fact
Speaker 1: that viruses can spread in this way and we need
Speaker 1: to be aware of that, and ventilation can be particularly important.
Speaker 1: The World Health Organization updated a scientific paper about the
Speaker 1: transmission of the Sasko V two virus on Thursday. It
Speaker 1: said it doesn't rule out the possibility of airborne transmission
Speaker 1: in crowded areas or indoor venues with poor ventilation. However,
Speaker 1: the Geneva Base Agency said more researchers needed because in
Speaker 1: such cases there may be alternative explanations as to how
Speaker 1: people got sick, such as respiratory droplets that fell onto surfaces.
Speaker 1: The w h O faces pressure from scientists led by
Speaker 1: Lydia Morawska, director of the International Laboratory for Equality and
Speaker 1: Health at Queensland University of Technology in Australia. Lydia argues
Speaker 1: that hamwashing and physical distancing alone aren't enough to stem
Speaker 1: infections because in the air and to research over the
Speaker 1: past three months found the presence of the spirals in
Speaker 1: the air and retrospectively that it incurreted people. Lydia and
Speaker 1: a colleague published an open letter in a medical journal
Speaker 1: last week calling on the w h O and other
Speaker 1: international groups to address the airborne transmission of COVID nineteen.
Speaker 1: The letter documented research that was backed by two d
Speaker 1: and thirty nine scientists. It asked officials to consider such
Speaker 1: precautions as increasing ventilation and avoiding recirculating potentially virus late
Speaker 1: and air, and buildings like hospitals and schools to avoid
Speaker 1: the kind of scenario played out in the restaurant in
Speaker 1: Guangzho in January. What's being debated isn't what happens when
Speaker 1: an infected person coughs or sneezes globes of virus laden liquid.
Speaker 1: That's a long established murder of infection. Rather, it's where
Speaker 1: the tiny particles known as microdroplets and aerosols stay afloat
Speaker 1: long enough to be inhaled and cause infection deeper in
Speaker 1: the lungs, and therefore what troll measures to use. Resolving
Speaker 1: these questions is becoming increasingly urgent as workplaces, schools, and
Speaker 1: colleges reopen in the United States, President Donald Trump has
Speaker 1: rejected school reopening guidelines that included increasing the circulation of
Speaker 1: outdoor air as too difficult. I spoke with Lydia in
Speaker 1: late June, a week before her letter came out to
Speaker 1: help clear up some questions I had. Um. I think
Speaker 1: people have kind of mistakenly thought that there are droplets
Speaker 1: and then there are aerosols, and that it's very sort
Speaker 1: of binary, when in fact, there's a whole gradient of
Speaker 1: size of these particulars that come out of one's respiratory tract.
Speaker 1: Can you talk about that, Well, there is a very
Speaker 1: big mess in in relation to the terminology, and it's
Speaker 1: often considered that this small part ticles emitted excribed by
Speaker 1: people are called aerosols and the pick are called droplets.
Speaker 1: It's nothing like this. Aerosols. The definition of aerosols are
Speaker 1: liquid and solid particles in the air. Now droplets are
Speaker 1: liquid particles, So basically droplets are liquid aerosols. So therefore
Speaker 1: we are not talking smaller be It has nothing to
Speaker 1: do with size. Our breath isn't usually visible, but when
Speaker 1: it's really cold, we can see it as puffs of stain.
Speaker 1: Lidia said it's a helpful visualization of how virus leading
Speaker 1: particles of varying sizes can be expelled from an infected
Speaker 1: person in a turbulent gas cloud. But are these virus
Speaker 1: leading aerosols infectious? This depends on the condition of the
Speaker 1: of the environment. Viruses of the skype are like cool
Speaker 1: air and drysh conditions, so if these are the conditions
Speaker 1: like in many office buildings, for example, this could be
Speaker 1: both conditions. If, on the other hand, we go outside
Speaker 1: where there is hot and in addition new we radiation,
Speaker 1: well within very short period of time, they will be deactivated,
Speaker 1: which suggests being outside is less risky for catching the
Speaker 1: coronavirus than being indoors well, very much so. But this
Speaker 1: is not the only aspect, since you'll be radiation. It
Speaker 1: is the very fast dilution outdoors, which is a well
Speaker 1: large reservoir. Dilution is very fast, so therefore the airborne
Speaker 1: transmission outdoors has very little chances to walk. Of course,
Speaker 1: there is still that contact if you are standing next
Speaker 1: to somebody for long time and this person's misses that
Speaker 1: you or something like this, that's the close contact. But
Speaker 1: otherwise in the airborne transmission it's much less likely to
Speaker 1: occur outdoors. In her letter last week, Lydia recommended high
Speaker 1: efficiency air filtration and jem sidle ultra violet lights they
Speaker 1: used to reduce the risk of airborne transmission. She also
Speaker 1: pointed to simpler protective measures like supplying clean out or
Speaker 1: air and avoiding overcrowding on public transport. Since siskov to emerge,
Speaker 1: Lydia's written or contributed to more than a dozen papers
Speaker 1: on the potential for the pandemics airborne spread. This makes
Speaker 1: me even sort of more on acced determined to get
Speaker 1: something done about this, because once this pandemic is over,
Speaker 1: probably won't happen dead quickly at once the pandemic is over. Again,
Speaker 1: this and this is not the issues are not recognized
Speaker 1: and not taking Carl and we are we were in
Speaker 1: the same situation during the next person. Evidence for airborne
Speaker 1: transmission of the coronavirus is still emerging and incomplete examples
Speaker 1: like the Gango restaurant suggests it's the most plausible explanation
Speaker 1: for how people were infected in some situations. While scientists
Speaker 1: conduct further research to better understand why, how, and to
Speaker 1: what extent these microscopic particles can spread, COVID nineteen. There
Speaker 1: are things we can do to mitigate that risk. Stay
Speaker 1: home if you're sick, coffin, sneeze into your elbow, observe
Speaker 1: physical distancing recommendations, avoid crowded, poorly ventilated indoor spaces, and
Speaker 1: where it's appropriate, where a face mask. That was Jason
Speaker 1: Gale in Melbourne. And that's it for our show. For
Speaker 1: coverage of the outbreak from one and twenty bureaus around
Speaker 1: the world, visit Bloomberg dot com slash coronavirus and if
Speaker 1: you like the show, please leave us a review and
Speaker 1: a rating on Apple Podcasts or Spotify. It's the best
Speaker 1: way to help more listeners find our global reporting. The
Speaker 1: Prognosis Daily edition is produced by Topher Foreheads Jordan Gaspore,
Speaker 1: Magnus Hendrickson and me Laura Carlson. Today's main story was
Speaker 1: reported by Jason Gale. Original music by Leo Sidran. Our
Speaker 1: editors are Rick Shine and Francesca Levi. Francesca Levie is
Speaker 1: Bloomberg's head of podcasts. Thanks for listening.