What is the influence of contact restrictions on the COVID-19-spread?
The measures carried out, the contact restriction for the protection against COVID-19 were really necessary, or even weaker measures would have led to a similar success? Researchers have been trying to answer this question.
The research group of Jonas Dehning from the Max-Planck-Institute for dynamics and self-organization (MPIDS) has analyzed the effect of the measures for the contact restriction on the COVID-19-spread and the results in the English-language journal “Science” published.
Consequences of the measures showed after two weeks
The consequences of the initiated in March, packages of Measures to combat COVID-19 were in Germany, with a two-week delay after each Intervention is fixable, reported the research team. But only after the third Intervention (a far-reaching ban on Contact) had gone the cases of COVID-19 decreased significantly.
The full extent of the interventions was that really necessary?
“Our analysis clearly shows the effect of the different measures that ultimately brought together a strong reversal of the trend,” emphasized Viola pries Mann, research group leader at the MPIDS. in a press release the results of research. The model calculations make it clear that the entire package of measures was necessary to stop the exponential growth in Germany.
Combined methods fühtren to more accurate results
In particular, in the first days of a pandemic, reliable short-term forecasts of the effects of measures for the decision-making persons or organisations of massive importance, are the researchers describe. If the reliability of such forecasts is initially called into question or if the case numbers are low, could help the so-called Bayesian modeling. For this purpose, the research group combined a calculation model for the Transmission of infections with Bayesian Parameter inference. Thus, the impact of the packages of Measures on the spread rate of the SARS-CoV-2 Virus, should be better assessable.
Changes always occurred two weeks after the Intervention
In Germany, there were in March, three major packages of Measures to combat COVID-19. This began with the cancellation of large public events, to the 8. March. It is the closure of educational institutions and many shops, as well as a far-reaching contact ban followed the end of the month. On the basis of the data about COVID-19-cases up to 21. April could the researchers identify three change points, each of which is two weeks after the Intervention is undetectable, and the slow spread of the Virus reflect.
When was a decisive decline in the disease?
Only with the third point of the change, which was initiated by the prohibition of Contact, however, reached a critical decline of the daily new cases and the exponetielle growth has been broken, according to the research team. In the further model calculations showed that a delay of the measures would have had only five days have already a serious impact.
When can be lifted the restrictions?
The researchers explain that, in view of the apparent two-week delay is important to allow for a lifting of the restrictions will only be considered if the number of active cases is so low that a two-week increase would not constitute a serious threat to the infrastructure of the health system.
“The first effects of the relaxations of 20. April, we see Recently in the case of numbers. And until we, the loosening of 11. May be able to evaluate, we have to wait two to three weeks,” explains Michael Wilczek, head of the research group at MPIDS. In the case of the lifting of restrictions, therefore, caution is warranted, warn the researchers. Due to the delay, it is also possible that a deteriorating Situation will stay for two weeks unnoticed. (as)