Sars-CoV-2 is highly infectious: If you know these risks, you are right

While most people are happy about the loosening of the Corona-measures, fears of a biologist Erin Bromage, they can lead to a rise in new infections. The adopted Social Distancing measures can’t protect the people ihmzufolge sufficient before the infections.

“It seems that many people currently seem to be easier, and I’m not sure why,” begins American biologist Erin Bromage a blog entry that he wants to the risks of the corona crisis point, which remain in spite of the Lockdown to continue to exist.

Relaxation could go to the Infection flare-up lead

The scientist who has put his emphasis on infectious diseases, immunity and epidemiology, feared a wide up of the new infections in the flames by the loosening of the measures. Also the Use of Social Distancing, he looks in certain contexts is critical.

According to Bromage’s important to remember where and how people become infected with the Virus.

Breathe, Touch, Speak: So the Virus gets in the human body

For this, he first distinguishes various ways the Virus in our body. “In order to infect, you have an infectious dose of the Virus will be exposed to,” says Bromage. Studies on other coronaviruses have shown that only a small amount of virus particles is necessary for a Person to infect. Bromage for his remarks, therefore, a risk of Infection from 1000 virus particles.

This might RUB a potential victim by a single breath, even the Eyes, or within ten breaths of 100 viral particles, or 100 breaths, each with ten virus particles to record: “Each of these situations can lead to an infection.”  

Reported corona virus cases in Germany (click on your state)


Erin Bromage explains in his post, where and how people infect his observations, that most likely with Sars-CoV-2:

  • In the bathroom: A Transfer by the chair, it is not yet proven. In bathrooms there are, however, plenty of other entry points for the Virus: As surfaces that are frequently touched are there, such as door handles and water taps. In addition, the toilet flushing, so Bromage could aerolisieren, infectious droplets. A risk of Infection lurking, especially in public toilets.
  • Breathe and Speak: A breath-by-breath sets according to the Bromage 50 to 5000 droplets in the nasal breathing be it rather less. Most of them fell quickly to the ground. Since exercising when Breathing in addition, in the rule, no pressure, not the viruses are excreted from the lower respiratory tract. Therefore, the breath includes a relatively small dose of virus particles. For Influenza virus studies have found in the past that when you Breathe to a maximum of 33 infectious particles per Minute are emitted.
    Talk can this amount, however, will increase tenfold. As the debate is damp, hanging out, among other things, of the volume, and the Loud, explains environmental medicine Claudia Traidl-Hoffmann from the Helmholtz Zentrum München and the Institute for environmental medicine at the Technical University of Munich. The “th” from the English, as in “thunderstorm” (a Storm) or sibilants were wonderful for demonstrations: “If an Infected person is in front of me and ‘thunderstorm’ says, there is a great risk to infect me.”
  • When coughing: How many viruses also spread Sars-CoV-2 through the air. As a droplet infection, but also in the Form of so-called Aerosol particles. The smallest suspended particles. In the meantime, there are several studies that suggest that these aerosols are a risk of Infection with the novel Virus. A single Huster, according to Bromage, up to 3000 droplets, which move with a speed of up to 80 kilometres per hour. Most of them are large and would quickly fall to the ground, some, however, were still in the air, and could travel in a few seconds by a whole room.
  • When Sneezing: When you Sneeze we will give about 30,000 droplets in our environment – at a speed of up to 30 kilometers per hour. In the droplets of an infected Person could be located according to the Bromage up to 200 million virus particles. This would be made when Sneezing to a large area of its surroundings.

The highest risk of Sars-CoV-2 to infect, is, accordingly, so if a infected you in the face coughs or sneezes. Then the critical value of 1000 inhaled virus particles is quickly reached.

Virus particles remain in the air, and spread indoors

The precipitated virus particles remain in the smallest of amounts, however a few minutes in the air, explains Bromage, therefore, it be could that you can become infected, if an infected Person a few minutes ago in a room coughed or sneezed has.

A study from China also suggests that the Corona-concentration inside buildings is usually higher than in public places. To this realization comes Bromage, and some concrete examples. He believed that 90 percent of all Transfers place indoors. In America, for example, there have been the biggest Virus outbreaks in nursing homes, prisons, religious sites and in workplaces such as call centres and meat factories.

The Corona-pandemic restricts the everyday life of the people in Germany. Especially for vulnerable groups such as seniors, everyday tasks are associated with a risk of infection. Therefore, now asked for solidarity! FOCUS Online has therefore launched the campaign “#corona care: Germany helps”. With you! All of the information you find here.

“Virus breeding grounds”: Where you use caution should

In terms of the back-up of the public life, considers that he, particularly public facilities in interior spaces as a possible “Virus breeding grounds”. Such as: Guangzhou Center for Disease Control and Prevention , researchers from Guangzhou have the air flow in a Chinese Restaurant studied. Red circles mark the future Infected.

  • Restaurants: carrier of the virus, the other people sitting at a table, or a Buffet to share, can the Virus via droplets and smear infection of the neighbor pass – through coughing, Breathing or touching of objects, as an experiment in Japan recently showed.
  • Offices: Several people spend a lot of time in the same rooms, and be able to the Virus so no longer will be exposed to. CDC blue marker shows the jobs of the Infected in a call center
  • Choirs: Sing more virus particles excreted as in Speaking and the people are usually for a longer period of time in a room together.
  • Family celebrations: birthdays, weddings, or funerals, according to the Bromage also a super spreader be. He points out that, unknowingly, with the Virus infected Person is supposed to be this way for the outbreak in Chicago responsible.

    Covid-19-Experiment in the Restaurant shows that After 30 minutes, the Virus has spread to everyone at the table spread

    FOCUS Online/Wochit Covid-19-Experiment in the Restaurant shows that After 30 minutes has Virus on everyone at the table spread

Social Distancing measures only show in the fresh air really effect

It is always a formula important: viral load * time. According to Bromage, each face-to-face contact more than ten minutes dangerous. He advises: “Social-Distancing measures are only in the fresh air for a brief Virus exposure.” There, Wind, solar radiation, air volume, et cetera would contribute to the reduction of infection. In the inside they are rooms, but not fully helpful.

Good ventilation but could be beneficial: For the evaporation of the droplets is crucial that the humidity in addition to temperature. The higher this is, the worse the evaporation of drops, explains Bernhard Weigand, of the Institute for thermodynamics of the air and space at the University of Stuttgart, among other things, to drop dynamics research. In General the faster the evaporation, the lower the risk of infection to say: The hotter and drier. Drafts blow in turn, the drops and boosts the evaporation.

The correct level of relative humidity in indoor environments plays a role

“What is important is the relative humidity.” This should not be, if you can be regulated to low. Then the drops fell so fast, and the heavier droplets fall more to the ground. “In addition, the mucous membranes dry out and become more susceptible to viruses.” Air conditioning systems could swirl the air in addition, well-equipped devices even virus filters from the air, he says.

It is crucial also to where the drops of velvet virus to arrive, and how infectious you are, adds Claudia Traidl-Hoffmann from the Helmholtz Zentrum München. On the nasal mucosa, it schnäuze you quickly. “If you inhale, you directly deep into the lungs, they are the greatest harm.”

More on Coronavirus

  • Symptoms, infection, incubation: we know about the Coronavirus

  • Interferon-Turbo: Sars-CoV-2 uses this perfidious Immune mechanism

  • “Surprisingly”: pathologist explains what Covid-19-Dead can tell you about the Virus

  • What can you do to strengthen your immune system

  • Use your judgment: What the next few months should be aware of

    Bromage appeals because of the known risk factors of the human mind: “Watch your environment and you can judge for yourself. How many people are there, how much air is circulated, and how long you will be in this environment?“

    Virus outbreaks due to purchases according to the Bromage by the way, is rather unlikely. He leads back to the fact that people in super markets and spend only a little time. In addition, no crowds, and thus, sufficient air is due to the contact restrictions available to circulate.

    For the employees the Whole look, however, is different. As they spend more time in the Shop, also increases your risk of infection.

    The lowest is the risk, are researchers around the world agree, in the fresh air.  

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    FOCUS Online/Wochit “Setting of infection with the disease is equal to”: According to this statement there is silence in the ZDF-Studio