How COVID-19 Spreads in a Closed Space

Graphics show how important wearing masks, regular ventilation, and reducing contacts is to stop the spread of the coronavirus.

We all love socializing over drinks or a good cup of coffee, reading the newspaper, or enjoying a snack while scrolling through Instagram in a lively environment.

However, one of the biggest consequences of the pandemic has been its huge impact on how we interact: After all, superspreading incidents can cause numerous new infections, and tracing them back from usually unaware victims often proves an insurmountable challenge.

According to El Pais, a COVID- surge in a nightclub produces an average of 27 infected hosts, compared to a mere 6 from attending a family gathering. The newspaper has presented an excellent graphic representation of how the coronavirus spreads in closed spaces and how effective wearing masks and regular circulation is in reducing the risk.

Here are various graphical representations of how COVID-19 spreads in a closed space, what we can do to prevent infections, and how different scenarios would play out over four hours within a bar, café, or eatery.

Patient Zero Enters the Space

The depicted bar’s capacity has been reduced by 50 %, with 3 staffers serving 9 customers. Windows are closed and the ventilation shut off.

How COVID-19 Spreads with no Masks, Measures, or Caution

If no further precautions are taken, an average of 9 persons will be infected within only four hours. This depiction shows the worst-case scenario.

Wearing Masks

If everyone in the space wears a masks, the number of infected people drops to “only” five within a four hour period.

Wearing Masks & Ventilation

Letting fresh air circulate through adequate ventilation and letting a draught in through the door, as well as shortening the duration of patrons’ stays and mandatory mask-wearing massively reduces the risk.

In such scenario, only one person is likely to get infected.

The Swiss Cheese Modell Against Covid-19

These interventions may seem individually small, but together they make the difference between a superspreading event with exponential growth and containing the virus.

The virology professor Ian MacKay has dubbed this strategy the “Swiss Cheese Respiratory Virus Pandemic Defense.” It recognizes that no single intervention is perfect at preventing spread. Each intervention (layer) has imperfections (holes), like a Swiss cheese.

But multiple interventions (layers) taken together improve the overall success massively.

Let’s do all our bit to stop the spread of the virus, with the help of these interventions and Swiss cheese.

Stay safe and stay healthy!

Daniel Jacob El-Sabeh
Daniel Jacob El-Sabeh
Daniel is half Austrian, with German Russian and Italian Lebanese roots, and grew up in Vienna and Lower Austria. Before joining Metropole, he worked as a Chef de Rang in numerous hotels. He's a hobby composer, film buff, and retro enthusiast.

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