Coronavirus: reproduction number rises to over 1 – but what does that mean?

With the so-called reproduction number is one of the decisive values for the infection happened in Germany recently increased and has exceeded a critical value. The number indicates how many more people is a Corona-Infected person on average infects.

According to the Robert Koch Institute from Sunday, the figure was 1.13 (data as of 10. May 0 PM). The RKI has repeatedly stressed, to let the Corona epidemic is tailing off, it would be necessary to the reproduction number below 1.

At the beginning of may, the value was according to the RKI-information over several days, between 0.7 and 0.8. On Wednesday, the RKI stated the value, at 0.65 (data as of 6. May 0 PM), and since then he had risen steadily. How to read this development, and to interpret, is anything but trivial.

R-represents the value of the current

First of all, you don’t need to know that the indication that an Infected person infects an average of 1.13 more people, is more reflective of the current Situation. For methodological reasons, the value refers to infections that took place before a certain time.

The possible effects of the infection happen on the Wednesday of the Federation and the länder agreed relaxations of the restrictions are due, you can not read it so.

In addition, the RKI stresses in a statement to the increase in the reproduction number, the R value is always fraught with a certain degree of uncertainty.

Because of the statistical fluctuations that would be reinforced by the overall reduction in Numbers, could not yet be assessed whether the during the last few weeks, declining Trend of new infections continue or there is a rise in case numbers.

“The increase in the estimated R-value makes it necessary to observe the development in the next few days very closely,” writes the RKI.

RKI: R-value is not the sole measure of all things

The reproduction number could not be used in isolation as a “measure of effectiveness/need for action”, writes the RKI on his website. Important is the absolute number of daily new infections, as well as the Severity of the disease are also.

The absolute number of new infections had to be small enough to allow an effective tracking of contact persons and not to overload the capacity of intensive care beds. The number of reported new infections per day, according to a RKI-Overview since the beginning of April, with the fluctuations decreasing.

Dirk Brockmann, an expert in modelling of infectious diseases at Humboldt University in Berlin, emphasized that the R-value is only a rough estimate and dependent on many factors.

Nevertheless, a hypothesis to be drawn from the increase in derived. Brockmann believes that it reflects that the people are already returned before the on Wednesday decided loosening slowly to normality.

You’ll meet again a little more and be generally more on the way. This will lead to more infections, according to the Thesis.

In General, the development of the infection events had to be observed over a longer period of time. The Whole commute, the R-value will always be 1 around, so Brockmann.

Sources

  • The Robert Koch Institute (2020): Daily situation report of the RKI to the Coronavirus-disease-2019 (COVID-19), retrieved on 11.05.2020: https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/Situationsberichte/2020-05-09-de.pdf?__blob=publicationFile
  • The Robert Koch Institute (2020): COVID-19-Dashboard, retrieved on 11.05.2020: https://experience.arcgis.com/experience/478220a4c454480e823b17327b2bf1d4/page/page_1/

Deutsche Presse-Agentur (dpa)

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