“We have to keep a distance from each other out of respect,” said the Chancellor in her television address to the German population.
Angela Merkel repeated what experts from the Robert Koch Institute, virologists, Minister of Health Jens Spahn and, last but not least, politicians from other countries who are even more affected by the coronavirus pandemic than Germany have said: Against the spread of Covid-19 currently helps best to reduce his social contacts as much as possible.
The Federal Government is thus following a strategy that other countries have already pursued – in China or South Korea, “social distancing” seems to have played a decisive step in containing the outbreaks. The procedure is also propagated on social media under the hashtag #flattenthecurve, i.e. flattening of the breakout curve, which rises steeply without measures. Nevertheless, on sunny afternoons you can still see groups of people in front of the remaining open cafes.
The health system can only withstand the pandemic if Germany manages to spread the expected number of illnesses over several months. If the number of cases exceeds the capacity of the health system, similar scenarios are threatened in Germany as in Italy, where medical personnel are reported to have to make decisions about life and death such as in the event of war.
To date, there is no vaccine or medication to treat Covid-19. In severe cases, doctors can only treat the symptoms of the sick. Since the virus first appears, there is still no immunity in society. Sars-CoV-2 can currently spread virtually unhindered – unless we don’t give the virus an opportunity to do so.
So what if we all stick to staying largely at home? In order to present the efficiency of the measures imposed in theory, we have simulated three scenarios, which, however, are not fully transferable to the current Covid 19 outbreak:
How would an infectious disease likely go if it were no measures restricting movement would give?
How could an infectious disease go if the population looked at “Social distancing” would keep – so everyone stays at home if possible and reduces social contacts?
What effect would one have? Curfew on the spread of an infectious disease?
The simulation shows how quickly an invented infectious disease could potentially spread in a city with 200 inhabitants – and how quickly the capacities of the healthcare system would be overloaded.
In the example, we assume that a healthy person would always be infected when in contact with a sick person. In the case of Covid-19, this need not necessarily be the case. Furthermore, we ignored deaths in the simulation and assumed that all 200 residents would be healthy again.
Even the severity of some disease courses is not shown in the simulation: It is assumed that the disease is the same for everyone. Likewise, the representation cannot represent the actual capacities of the health system, which are not only very different internationally, but also in Germany from region to region.
How #flattenthecurve works theoretically
So let us assume that the freedom of movement would not be restricted at all and that we would continue our public life as before: The 200 people in the simulated city (blue dots) move at random. A person gets sick (orange). Every time you come into contact with a healthy person, she infects them – the blue person also turns orange and infects other people. The entire city is infected within a short time, with some of the very early sick people recovering again (light blue).
The bar above the simulation shows how quickly the capacities of the health system of the invented city would have been exceeded if the simulated outbreak had gone uncontrolled.
Now let’s take a look at what happens if 75 percent of city dwellers stick to limiting social contacts as much as possible and stay at home as much as possible: These 75 percent are shown in the simulation as blue, static dots. A quarter of the population continues to move freely.
Another person of the 200 inhabitants falls ill and infects others. Because a majority of the points people do not move, the invented disease spreads much more slowly. While almost all of them were sick at once in the first simulation, many are now healthy again while new ones become infected.
The bar chart above the simulation shows that the capacities would hardly be exceeded, the course would have been stretched over a much longer period. The Federal Government is trying to achieve a similar scenario with its current measures. But this only works if everyone voluntarily adheres to the guidelines.
Spain, France and Italy have shown that there could be another escalation level: the curfew. It could be imposed if it does not appear in a few days that the measures taken will have an effect – or if it becomes apparent that the population does not comply with the request to voluntarily reduce social contacts.
In the event of a curfew, we should probably only be able to leave the house if we want to go to the doctor, the pharmacy or to go shopping. Even people with systemically important jobs are still allowed outside. Everyone else would have to endure in their apartments, otherwise they could face fines. It is uncertain how many would be affected by the curfew. For the simulation, we assumed that around 87 percent of the 200 invented residents were not allowed to move freely. So only about every eighth would move.
The simulation shows that this measure would have by far the greatest effect in containing the invented disease: only a quarter of the city’s 200 residents would fall ill and the health system would not even have come close to the limit. In the last graphic, however, we assume that the curfew already existed when the first illness occurred.
However, since there are already more than 12,000 infected people in Germany (the number of unreported cases is probably much higher), such a scenario is no longer possible. Nevertheless, the graphic shows that an extreme restriction of freedom of movement, such as was now imposed in the Bavarian city of Mitterteich, could probably slow down the spread.
The highly simplified simulations are intended to illustrate the possible spread of a fictitious disease – and show to what extent restrictive measures could have an impact on a pandemic. They cannot be directly transferred to the current Covid 19 pandemic because numerous parameters are neglected. Nor do we go into the fact that social distancing will only make a difference if it is maintained over a very long period. According to experts, it could take months before we can almost get back to normal everyday life.