From The Asian Reporter, V30, #11 (October 5, 2020),
pages 8 & 12.
Tiny airborne particles may pose a big
coronavirus problem
By Malcolm Ritter
The Associated Press
NEW YORK — At a University of Maryland lab, people infected
with the new coronavirus take turns sitting in a chair and
putting their faces into the big end of a large cone. They
recite the alphabet and sing or just sit quietly for a half
hour. Sometimes they cough.
The cone sucks up everything that comes out of their mouths
and noses. It’s part of a device called "Gesundheit II" that is
helping scientists study a big question: Just how does the virus
that causes COVID-19 spread from one person to another?
It clearly hitchhikes on small liquid particles sprayed out
by an infected person. People expel particles while coughing,
sneezing, singing, shouting, talking, and even breathing. But
the drops come in a wide range of sizes, and scientists are
trying to pin down how risky the various kinds are.
The answer affects what we should all be doing to avoid
getting sick. That’s why it was thrust into headlines last month
when a U.S. health agency appeared to have shifted its position
on the issue, but later said it had published new language in
error.
The recommendation to stay at least 6 feet apart — some
authorities cite about half that distance — is based on the idea
that larger particles fall to the ground before they can travel
very far. They are like the droplets in a spritz of a window
cleaner, and they can infect somebody by landing on their nose,
mouth, or eyes, or maybe being inhaled.
But some scientists are now focusing on tinier particles, the
ones that spread more like cigarette smoke. Those are carried by
wisps of air and even upward drafts caused by the warmth of our
bodies. They can linger in the air for minutes to hours,
spreading throughout a room and building up if ventilation is
poor.
The potential risk comes from inhaling them. Measles can
spread this way, but the new coronavirus is far less contagious
than that.
For these particles, called aerosols, "6 feet is not a magic
distance," says Linsey Marr, a leading researcher who is
studying them at Virginia Tech in Blacksburg. But she says it’s
still important to keep one’s distance from others — "the
farther the better" — because aerosols are most concentrated
near a source and pose a bigger risk at close range.
Public health agencies have generally focused on the larger
particles for coronavirus. That prompted more than 200 other
scientists to publish a plea in July to pay attention to the
potential risk from aerosols. The World Health Organization
(WHO), which had long dismissed a danger from aerosols except in
the case of certain medical procedures, later said that aerosol
transmission of the coronavirus can’t be ruled out in cases of
infection within crowded and poorly ventilated indoor spaces.
The issue drew attention recently when the U.S. Centers for
Disease Control (CDC) and Prevention posted and then deleted
statements on its website that highlighted the idea of aerosol
spread. The agency said the posting was an error, and that the
statements were just a draft of proposed changes to its
recommendations.
Dr. Jay Butler, CDC’s deputy director for infectious disease,
told The Associated Press that the agency continues to believe
larger and heavier droplets that come from coughing or sneezing
are the primary means of transmission.
Butler told a scientific meeting in August that current
research suggests aerosol spreading of the coronavirus is
possible but it doesn’t seem to be the main way that people get
infected. Further research may change that conclusion, he added,
and he urged scientists to study how often aerosol spread of the
coronavirus occurs, what situations make it more likely, and
what reasonable steps might prevent it.
Marr said she thinks infection by aerosols is "happening a
lot more than people initially were willing to think."
As a key piece of evidence, Marr and others point to
so-called "superspreader" events where one infected person
evidently passed the virus to many others in a single setting.
In March, for example, after a choir member with coronavirus
symptoms attended a rehearsal in Washington state, 52 others who
had been seated throughout the room were found to be infected
and two died. In a crowded and poorly ventilated restaurant in
China in January, the virus evidently spread from a lunchtime
patron to five people at two adjoining tables in a pattern
suggesting aerosols were spread by the air conditioner. Also in
January, a passenger on a Chinese bus apparently infected 23
others, many of whom were scattered around the vehicle.
Butler said such events raise concern about aerosol spread
but don’t prove it happens.
There could be another way for tiny particles to spread. They
may not necessarily come directly from somebody’s mouth or nose,
says William Ristenpart of the University of California, Davis.
His research found that if paper tissues are seeded with
influenza virus and then crumpled, they give off particles that
bear the virus. So people emptying a wastebasket with tissues
discarded by somebody with COVID-19 should be sure to wear a
mask, he said.
Scientists who warn about aerosols say current
recommendations still make sense.
Wearing a mask is still important, and make sure it fits
snugly. Keep washing those hands diligently. And again, staying
farther apart is better than being closer together. Avoid
crowds, especially indoors.
Their main addition to recommendations is ventilation to
avoid a buildup of aerosol concentration. So, the researchers
say, stay out of poorly ventilated rooms. Open windows and
doors. One can also use air-purifying devices or
virus-inactivating ultraviolet light.
Best of all: Just do as much as you can outdoors, where
dilution and the sun’s ultraviolet light work in your favor.
"We know outdoors is the most spectacularly effective
measure, by far," says Jose-Luis Jimenez of the University of
Colorado-Boulder. "Outdoors it is not impossible to get
infected, but it is difficult."
The various precautions should be used in combination rather
than just one at a time, researchers say. In a well-ventilated
environment, "six feet (of separation) is pretty good if
everybody’s got a mask on" and nobody stays directly downwind of
an infected person for very long, says Dr. Donald Milton of the
University of Maryland School of Public Health, whose lab houses
the Gesundheit II machine.
Duration of exposure is important, so there’s probably not
much risk from a short elevator ride while masked or being
passed by a jogger on the sidewalk, experts say.
Scientists have published online tools for calculating risk
of airborne spread in various settings.
At a recent meeting on aerosols, however, Dr. Georges
Benjamin, executive director of the American Public Health
Association, noted that preventive steps can be a challenge in
the real world. Keeping apart from other people can be difficult
in homes that house multiple generations. Some old buildings
have windows that were "nailed shut years ago," he said. And "we
have far too many communities where they simply don’t have
access to clean water to wash their hands."
It might seem strange that for all the scientific frenzy to
study the new coronavirus, the details of how it spreads can
still be in doubt nine months later. But history suggests
patience.
"We’ve been studying influenza for 102 years," says Milton,
referring to the 1918 flu epidemic. "We still don’t know how
it’s transmitted and what the role of aerosols is."
The Associated Press Health and Science Department receives
support from the Howard Hughes Medical Institute’s Department of
Science Education. The AP is solely responsible for all content.
* * *
From The Asian Reporter, V30, #11 (October 5, 2020),
page 8.
A look at the impact of the coronavirus
By The Associated Press
As it marched from east to west this year, the coronavirus
pandemic sank economies and transformed social interactions. It
shut schools and businesses, stopped the sports and
entertainment industries dead in their tracks, and even brought
low the Olympic Games.
And it killed. One million deaths have been recorded
worldwide to date, according to data tracked by Johns Hopkins
University.
The effects were global — but also personal. The virus
changed how people socialized and shopped, worked and dressed.
It changed how they cared for their loved ones and how they
mourned them.
It even changed the language they used. The word "hero" was
employed with more frequency — and the definition expanded to
include delivery and sanitation workers, cleaners and waiters.
And, of course, healthcare workers, who in China and Italy, Iran
and South Africa, the United States and Brazil toiled in hazmat
suits for hours on end to treat the sick.
The virus changed how people interacted and how they thought
about interaction. People isolated to stay healthy — and then
worried about what isolation was doing to their health.
In Spain, one of the hardest-hit countries, nursing home
residents were shut off from the outside world for months in an
effort to protect them. When visitors were allowed again,
husbands and wives pressed lips to plastic sheeting for several
minutes; mothers and daughters clutched each other through the
film.
Many people were unable to say goodbye to their loved ones
because of restrictions at hospitals; others held them in their
final moments, draped head-to-toe in protective gear. Funerals
were also sterile affairs, if they happened at all.
And still the pandemic is far from over. The toll is
climbing. By around 5,000 a day, a death every 17 seconds
somewhere in the world.
* * *
From The Asian Reporter, V30, #11 (October 5, 2020),
pages 8 & 15.
Fact check: How can I tell the difference between the flu and
COVID-19?
By The Associated Press
How can I tell the difference between the flu and COVID-19?
It’s impossible to tell without a test. Influenza and
COVID-19 have such similar symptoms, you may need to get tested
to know what’s making you miserable.
Body aches, sore throat, fever, cough, shortness of breath,
fatigue, and headaches are symptoms shared by the two.
One difference? People with the flu typically feel sickest
during the first week of illness. With COVID-19, people may feel
the worst during the second or third week, and they may be
sicker for a longer period.
Another difference: COVID-19 is more likely than the flu to
cause a loss of taste or smell. But not everyone experiences
that symptom, so it’s not a reliable way to tell the viruses
apart.
That leaves testing, which will become more important as flu
season ramps up this fall in the Northern Hemisphere. Doctors
will need to know test results to determine the best treatment.
It’s also possible to be infected with both viruses at the
same time, said Dr. Daniel Solomon, an infectious
diseases expert at Brigham and Women’s Hospital and Harvard
Medical School in Boston.
Whether you get tested for one or both viruses may depend on
how available tests are and which viruses are circulating where
you live, he said.
"Right now we are not seeing community transmission of
influenza, so widespread testing for the flu is not yet
recommended," Solomon said.
Both the flu and coronavirus spread through droplets from the
nose and mouth. Both can spread before people know they are
sick. The flu has a shorter incubation period — meaning after
infection it can take one to four days to feel sick — compared
to the coronavirus, which can take two to 14 days from infection
to symptoms.
On average, COVID-19 is more contagious than the flu. But
many people with COVID-19 don’t spread the virus to anyone,
while a few people spread it to many others. These
"super-spreader events" are more common with COVID-19 than flu,
Solomon said.
Preventing the flu starts with an annual flu shot tailored to
the strains of the flu virus that are circulating. Health
officials would like to see record numbers of people get flu
shots this year so hospitals aren’t overwhelmed with two
epidemics at once.
There’s no vaccine yet for COVID-19, although several
candidates are in the final testing stages.
Precautions against COVID-19 — masks, social distancing,
handwashing — also slow the spread of the flu, so health
officials hope continued vigilance could lessen the severity of
this year’s flu season.
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