A schoolgirl became infected with Corona within a very short time - even though she was 6.5 meters away from the positive person.
In some situations two meters is not enough.
This is shown by a
corona study from South Korea
.
There, a schoolgirl was
infected
with
Corona
*
within five minutes
- even though she was 6.5 meters
away
from the
Corona-positive person
.
Researchers suspect air currents and are making suggestions that could defuse the situation.
Seoul - How to behave
properly
in the
corona pandemic
?
For many months now, all the agencies in Germany dealing with the topic - from the Robert Koch Institute (RKI) to the Federal Ministry of Health - have been pointing out the so-called
AHA rules
: keep your distance, observe hygiene rules and wear an everyday mask.
In
Germany
, a
distance
of "at least 1.5 meters" is generally recommended.
The Federal Center for Health Education (BZgA) states: "The probability of coming into contact with virus-containing droplets and aerosols is increased, especially within a radius of one to two meters from a
person infected
with the
Sars-CoV-2 coronavirus
. "
Corona infection: In some situations, a distance of two meters is not enough
But now a
study from South Korea
shows
that a distance of one and a half or two meters may not be enough in certain situations
to protect
yourself from a
corona infection
.
A team of researchers led by epidemiologist Lee Ju-Hyung looked into
a
mysterious corona case
in the South Korean city of Jeonju
for the
study
, which was published in the Journal of Korean Medical Science
.
A schoolgirl there was infected with
Corona in
mid-June
- although there has not been a single
Corona case
in the city for two months
.
And the province in which the city is located had not
reported
any new
corona cases
for a month at this time
.
The infected schoolgirl had also
not
left
the region
.
According to the researchers, she moved mainly between her
home
and
school
.
With the help of smartphone location data, the researchers found that the path of the schoolgirl had for a short time intersected the path of a businesswoman visiting the city.
The businesswoman was
corona-positive
at the time of the overlap
, as the researchers knew.
Corona study from South Korea: schoolgirl infected within 5 minutes
The two women were in a restaurant at the same time for about five minutes - a period of time that, according to the researchers, was enough for the schoolgirl
to become infected with corona
.
And that although the businesswoman and the schoolgirl were far apart and apparently neither spoke to each other nor touched the same surfaces one after the other.
With the help of
video recordings
, the researchers reconstructed the brief encounter between the two women.
They found out the exact seat spacing between the restaurant visitors, determined how the
air conditioning was
set and which
seats
in the restaurant were occupied.
+
Schematic representation of the situation in the restaurant.
You can see the corona-positive businesswoman (B), the schoolgirl (A) and the other person who has become infected (C).
Person D is also marked as a confirmed corona case, but does not play a role in the study because the person was not yet contagious at the time in question.
© The Korean Academy of Medical Sciences
Corona study from South Korea: Corona infection in the restaurant over 6.5 meters away
In their
study
, the researchers describe in detail what the conditions were like in the
restaurant
: the schoolgirl was sitting at a table, accompanied, and talking
without a mask
.
The businesswoman was sitting 6.5 meters away from the schoolgirl and was also talking to an accompanying person without a mask.
Five minutes after the businesswoman entered the restaurant, the student left.
Another person who was also
infected
with
Corona
that day
entered the restaurant shortly afterwards and settled down at a distance of 4.8 meters from the
Corona-positive
businesswoman.
The two stayed that distance for 21 minutes before the businesswoman left the restaurant.
In order to rule out that the student and the other person had been
infected
with
corona
on another occasion
, the researchers examined the
genetic
properties of the
corona
viruses
with which the three patients were infected.
It turned out: The student and the other person had certainly been
infected
with
Corona
from the businesswoman
.
However, the
corona infection of
a fourth person present had no influence on the infection process in the restaurant, since the person was not yet contagious at the time in question.
Evidence of Long-Distance Droplet Transmission of SARS-CoV-2 by Direct Air Flow in a Restaurant in Korea (Journal of Korean Medical Science) https://t.co/WUV3Lw0PtU #svpol #pldebatt # COVID19 via @yvessmith pic.twitter .com / Ss3ewYt5eB
- rds (@ robotnr7312) December 15, 2020
Corona study: Airflow apparently played a role in the spread of the coronavirus
For their study, the researchers paid particular attention to the
air flow in the restaurant
and the
air conditioning
.
That was during the time in question
actively
and
moving the air in the restaurant
.
The
researchers measured the
following
airflow
speeds
in the restaurant:
Air flow between businesswoman and student: Maximum 1 meter per second (3.6 km / h)
Air flow between business woman and other infected person: maximum 1.2 meters per second (4.3 km / h)
No other people were infected in the restaurant - although some of them were much closer to the businesswoman.
The researchers' thesis:
They were not sitting in a
direct draft
and
therefore were not infected
.
The people accompanying the two newly infected people were also not infected with
Corona
- possibly because their faces were not directed towards the infected businesswoman, the researchers suspect.
Corona infection indoors: air movement has something to do with it
The conclusions of the researchers:
the
movement of air in the interior
may have transported droplets over a distance of 6.5 meters in the case in - so many that within a maximum of
five minutes
a person
with Corona infected
had.
From this, the researchers conclude:
Corona infection via droplets
can occur within a short period of time over a distance greater than two meters if there is
air movement
such as from an air conditioning system.
"The rules for quarantine and epidemiological investigation need to be updated to take these factors
into account
when controlling and preventing
Covid-19
," the researchers demand in their study.
They propose the following specific measures:
Greater distance between tables in indoor restaurants (more than 1-2 meters).
Alternatively: set up a windbreak that takes the air flow into account.
In environments such as restaurants, masks should only be removed while eating and worn the rest of the time.
But is the
Corona study from South Korea
currently relevant in Germany?
Restaurants have been closed for some time and the
lockdown
*, which came into
effect
on December 16, further restricted similar situations.
But especially in winter and on the upcoming Christmas
days
, the result of the
Corona study is
of interest: In winter, more people meet indoors instead of outdoors.
And especially at
Christmas
, visitors usually come home: Up to four closely related people from different households can come to visit at Christmas *.
+
The virus has an easy time indoors.
© Peter Kneffel / dpa
Inside,
situations can quickly arise in which the
coronavirus
can spread easily: It's
narrow
, it's
stuffy
and you
don't
wear
a mask
because you
feel safe with
your
family
.
Very few will have air conditioning installed at home, but at the same time the conditions are in most cases tighter than in restaurants.
The
Corona study
from
South Korea
can therefore be seen as a
warning
: Even at
Christmas
you should try to keep your distance as possible.
Because
you are nowhere safe
from the
coronavirus
- and under certain conditions, even the
distance rule
is not
enough
.
(Tanja Banner)
* fr.de is part of the nationwide Ippen-Digital central editorial team.
