A Korean Air employee.
- The Korea Centers for Disease Control and Prevention confirmed the Korean Air flight infected with coronavirus serviced a flight to Israel with 31 reported cases of the virus.
- The South Korean passengers onboard the flight were returned to South Korea, with the flight attendant reportedly servicing additional flights after returning.
- South Korean media is reporting that the flight attendant worked flights between Seoul and Los Angeles, a popular route for the airline.
The South Korean Center for Disease Control and Prevention has confirmed that the Korean Air flight attendant diagnosed with coronavirus was onboard a flight from Seoul to Tel Aviv where 31 cases of the virus were reported. The flight was operated on February 15 with around 200 passengers onboard, the Times of Israel reported.
Though Korean Air has not released the flight attendant's full routing since contracting the virus, it's believed that the employee worked additional flights to and from Seoul in the days following the flight to Israel, according to South Korean news outlets, including flights between South Korea and the US.
As reported cases of the virus began to rise in South Korea, multiple Asian nations began restricting entry on visitors from the country, Israel included. South Koreans traveling on the flight to Israel's second most populous city were denied entry to the country, returning home on the same aircraft, according to the New York Times.
The US Centers for Disease Control and Prevention issued a travel warning for South Korea on Monday, advising against non-essential travel.
Korean Air Boeing 777
The flight attendant serviced KE957, Korean Air's only scheduled service from Seoul to Tel Aviv, on February 15. As Israel's primary airport, Ben Gurion International Airport serves as the main airports for both Tel Aviv and Jerusalem, as well as most cities in the northern half of the country, with most visitors to Israel passing through the airport.
The flight was operated by a Boeing 777-200, according to FlightAware data, which seat over 200 passengers. The Times of Israel reported that around 200 South Koreans were on board the flight, with over 30 being diagnosed with the virus, according to the South Korea Center for Disease Control.
After returning to Seoul, the Los Angeles Times reported that the flight attendant may have operated two additional flights between the South Korean capital and Los Angeles. The flights that were serviced by the flight attendant, KE17 and KE12, reportedly took place on February 19 and 20, respectively, with a one-night layover in Los Angeles, the LA Times reported.
Korean Air operates multiple daily flights between Seoul and Los Angeles with some of its largest aircraft including the Airbus A380 and a Boeing 747-8i. The flights that the flight attendant reportedly worked were operated by the Airbus A380, the world's largest passenger jet seating over 400 passengers in Korean Air's configuration.
Passengers who flew from the Chinese
city of Wuhan, the epicenter of a pneumonia-causing new coronavirus, go through
quarantine at Narita airport near Tokyo on Jan. 23, 2020. Seen in the
foreground is a thermographic monitor set up to check their body temperatures.
PHOTOGRAPH BY KYODO VIA AP
IMAGES
SCIENCEEXPLAINER
Here’s how
coronavirus spreads on a plane—and the safest place to sit
Global travel
opens new roads for outbreaks, like coronavirus and the flu—but which is more
dangerous, and how can you stay safe?
7 MINUTE READ
BY AMY MCKEEVER
PUBLISHED FEBRUARY 6, 2020
WHEN AN OUTBREAK strikes, it is natural to become leery of
hopping on an airplane. It is even more alarming when two serious viruses are
circulating at once.
The world is gripped by a new coronavirus that
started in China and has since moved into more than two dozen other countries,
including the United States. Meanwhile, it is also flu season, which so
far has caused 10,000 deaths in the U.S.
Major airports have begun screening passengers for
the coronavirus, and more than three dozen airlines—including Delta, American and United—have
cut their flights to mainland China. But those measures may not provide much
solace to anyone who has to board a flight.
After all, you can avoid the person who is sneezing in line at Cinnabon, but you’re more or less left to fate once you’ve strapped on that seatbelt inside a flying metal canister.
After all, you can avoid the person who is sneezing in line at Cinnabon, but you’re more or less left to fate once you’ve strapped on that seatbelt inside a flying metal canister.
While there is still much to learn about the Wuhan
outbreak, scientists do know a bit about similar coronaviruses and other
respiratory illnesses like influenza. So how do those viruses spread—and
specifically on airplanes? And how serious is the coronavirus threat compared
to the likes of influenza? Let’s take a look.
How do
respiratory illnesses spread in general?
If
you’ve ever sneezed into your arm or steered clear of an office colleague with
a hacking cough, you already know the basics of how respiratory illnesses
spread.
When an infected person coughs or sneezes, they
shed droplets of saliva, mucus, or other bodily fluids. If any of those
droplets fall on you—or if you touch them and then, say, touch your face—you
can become infected as well.
These droplets are not affected by air flowing
through a space, but instead fall fairly close to where they originate.
According to Emily Landon, medical director of antimicrobial stewardship
and infection control at the University of Chicago Medicine, the hospital’s
guidelines for influenza define exposure as being within six feet of an
infected person for 10 minutes or longer.
“Time and distance matters,” Landon says.
Respiratory illnesses can also be spread through
the surfaces upon which the droplets land—like airplane seats and tray tables.
How long those droplets last depends both on the droplet and the surface—mucus
or saliva, porous or non-porous, for example. Viruses can vary dramatically in
how long they last on surfaces, from hours to months.
There’s also evidence that respiratory viruses can
be transmitted through the air in tiny, dry particles known as aerosols. But,
according to Arnold Monto, professor of epidemiology and global public health
at the University of Michigan, it’s not the major mechanism of transmission.
“To be sustained, to allow true aerosols, the virus has to be able to survive in that environment for the amount of time it’s exposed to drying,” he says. Viruses would rather be moist, and many fade from being infectious if left dry for too long.
“To be sustained, to allow true aerosols, the virus has to be able to survive in that environment for the amount of time it’s exposed to drying,” he says. Viruses would rather be moist, and many fade from being infectious if left dry for too long.
What does that
mean for airplanes?
The World Health Organization defines contact with an
infected person as being seated within two rows of one another.
But people don’t just sit during flights,
particularly ones lasting longer than a few hours. They visit the bathroom,
stretch their legs, and grab items from the overhead bins. In fact, during the
2003 coronavirus outbreak of the severe acute respiratory syndrome (SARS), a
passenger aboard a flight from Hong Kong to Beijing infected people well
outside the WHO’s two-row boundary. The New England Journal of Medicine noted that the WHO criteria “would have missed 45 percent
of the patients with SARS.”
Inspired in part by that case, a team of public
health researchers set out to study how random movements about the airplane
cabin might change passengers’ probability of infection.
Passengers in window seats have the lowest likelihood
of coming in contact with an infected person...
Probability of direct contact with the infected person
...but illnesses are most likely to be transmitted only to
passengers within one row of the infected person.
Probability of being infected
Less than 1 percent
5 to 20
80 to 100
The “FlyHealthy Research Team” observed the
behaviors of passengers and crew on 10 transcontinental U.S. flights of about
three and a half to five hours. Led by Emory University's Vicki Stover Hertzberg and Howard Weiss,
they not only looked at how people moved about the cabin, but also at how that
affected the number and duration of their contacts with others. The team wanted
to estimate how many close encounters might allow for transmission during
transcontinental flights.
“Suppose you’re seated in an aisle seat or a
middle seat and I walk by to go to the lavatory,” says Weiss, professor of
biology and mathematics at Penn State University. “We’re going to be in close
contact, meaning we’ll be within a meter. So if I’m infected, I could transmit
to you...Ours was the first study to quantify this.”
As the study revealed in 2018, most passengers left their seat at some
point—generally to use the restroom or check the overhead bins—during these
medium-haul flights. Overall, 38 percent of passengers left their seats once
and 24 percent more than once. Another 38 percent of people stayed in their
seats throughout the entire flight.
This activity helps pinpoint the safest places to
sit. The passengers who were least likely to get up were in window seats: only
43 percent moved around as opposed to 80 percent of people seated on the aisle.
Accordingly, window seat passengers had far fewer
close encounters than people in other seats, averaging 12 contacts compared to
the 58 and 64 respective contacts for passengers in middle and aisle seats.
Choosing a window seat and staying put clearly
lowers your likelihood of coming into contact with an infectious disease. But,
as you can see in the accompanying graphic, the team’s model shows that
passengers in middle and aisle seats—even those that are within the WHO’s
two-seat range—have a fairly low probability of getting infected.
Weiss says that’s because most contact people have
on airplanes is relatively short.
“If you’re seated in an aisle seat, certainly
there will be quite a few people moving past you, but they’ll be moving
quickly,” Weiss says. “In aggregate, what we show is there’s quite a low
probability of transmission to any particular passenger.”
The story changes if the ill person is a crew
member. Because flight attendants spend much more time walking down the aisle
and interacting with passengers, they are more likely to have additional—and
longer—close encounters. As the study stated, a sick crew member has a
probability of infecting 4.6 passengers, “thus, it is imperative that flight
attendants not fly when they are ill.”
What does it mean
for the new coronavirus?
As
Weiss points out, we don’t know yet the preferred way that the new coronavirus
transmits. It could be primarily through respiratory droplets, physical contact
with saliva or diarrhea followed by oral consumption of viral material, or
perhaps even aerosols.
He notes that this model doesn’t include the
transmission of aerosols, though the FlyHealthy team hopes to research this
topic in the future. In the study, the researchers also warn that this model
cannot be directly extrapolated for long-haul flights or airplanes with more
than one aisle.
Landon agrees that we don’t yet know how the
coronavirus transmits, but believes the results of this study are applicable.
All previous coronaviruses have transmitted through droplets, she notes, so it
would be unusual if this new pathogen was different. And indeed, the new
coronavirus is behaving much like SARS in many respects. Both are zoonotic, meaning they started in animals before jumping
to humans, and both appear to have started in bats. The pair also transmit from
human to human and have a long incubation period—up to 14 days for the Wuhan coronavirus, compared to
about two for influenza—which means that people might be sick and
transmitting the disease before symptoms show up.
With all that in mind, Landon suggests following
the CDC guidance for infectious diseases when you’re on an
airplane.
That includes washing your hands with regular soap
or using an alcohol-based hand sanitizer after touching any surface—especially
since there’s evidence that coronaviruses last longer on surfaces than other
illnesses, around three to 12 hours.
You should also avoid touching your face and
contact with coughing passengers by whatever means possible.
What’s worse, the
coronavirus or influenza?
There are many ways to estimate the risk posed by a
disease, but let’s focus on two numbers often used by public health
researchers: the reproduction number and the case-fatality ratio.
The reproduction number—R0 or “r naught”—simply refers to the
number of additional people that an infected person typically makes sick. Maia
Majumder, a faculty member at Boston Children’s Hospital and Harvard Medical
School, has been tracking exactly that.
Her preliminary results indicate a transmissibility rate for the new coronavirus
ranging from 2.0 to 3.1 people. That’s higher than influenza—1.3 to 1.8—but
similar to SARS, which has a basic
reproduction number in the 2 to 4 range. So, coronaviruses are
slightly more prone to spreading between people.
With flu we have vaccines, a couple antivirals. We
don’t have those for this coronavirus.
ARNOLD MONTO, UNIVERSITY OF MICHIGAN
The case-fatality ratio—or death-to-case ratio—is
the number of people killed by disease divided by the number of people who
catch it. Seasonal influenza, despite being considered a global scourge,
technically kills a relatively small proportion of its cases, with a
case-fatality ratio around 0.1 percent. The reason the flu is an annual public
health emergency is because it infects boatloads of people—35.5 million in the U.S. across 2018 and 2019, which led to
490,000 hospitalizations and 34,200 deaths. That’s why health officials perpetually
recommend that people receive a flu shot.
The case-fatality ratio also helps explain why
public health agencies send up alerts over emerging outbreaks of coronaviruses.
SARS had a case-fatality rate of 10 percent, about 100 times higher than
influenza, and the rate for the new coronavirus is currently near 3 percent,
which is on par with the 1918 Spanish influenza pandemic.
If SARS or the Wuhan coronavirus ever reached
millions of people, it could be devastating. Unlike with influenza, Landon
says, the entire human population is susceptible to this coronavirus because no
one has ever had it before—and there is no specific treatment like a vaccine.
Health officials and the public are dependent on infection control, such as washing hands, reducing contact with afflicted individuals and quarantines. Monto suggests that these public health measures could make a difference in turning the tide against this coronavirus as they did with SARS.
Health officials and the public are dependent on infection control, such as washing hands, reducing contact with afflicted individuals and quarantines. Monto suggests that these public health measures could make a difference in turning the tide against this coronavirus as they did with SARS.
“That’s the hope here, that
it can be controlled by standard public health measures—because that’s what
we’ve got,” he says. “With flu we have vaccines, a couple antivirals. We don’t
have those for this coronavirus.”
Editor’s Note: This story originally published on January 28, 2020. It has been updated to reflect the latest statistics and news on airline cancellations.
Editor’s Note: This story originally published on January 28, 2020. It has been updated to reflect the latest statistics and news on airline cancellations.
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