RKI-Corona study: Lockdown has little influence on the spread of the virus

Translation of RKI-Corona-Studie: Lockdown kaum Einfluss auf Ausbreitung des Virus, Sputnik Deutschland, 25.04.2020 (MbS News, 25.4.2020)

Chancellor Angela Merkel at the press conference on April 20 evaluated the decline in Covid-19 infections as a result of rigid contact restrictions. However, calculations by the highest federal authority responsible for health, the Robert Koch Institute (RKI), clearly speak against it. An improved procedure for “Estimating the Current Development of the SARS-CoV-2 Epidemic”, which the RKI published on April 15 in its Epidemiological Bulletin 17/2020 in a first version published, confirms what many experts have predicted: the strict contact barriers do little to curb it.

Even if the course of the daily published case numbers plays a big role in politics and media, it says little about the actual infection process. On the one hand, only a part of the infected is recorded because, as the RKI also points out, not all infected people develop symptoms. Not everyone who develops symptoms goes to a doctor’s office. Not everyone who goes to the doctor is tested. And not all those who test positive are also recorded in a survey system.Indeed, a number of Studies indicates that the total number of people infected so far is between 3 and 20 times as large as that of those recorded cases. On the other hand, the more or less long time between an infection or the visible onset of a disease and the day the case was recorded massively distorts the spread curve.

Important data

According to the RKI, it usually takes five to ten days for a case to find its way into your system. This is shown not only by the figures published by the RKI, but also by other institutions such as the US Johns Hopkins University (JHU). Even more than the delay in reporting, which causes the RKI to lag behind, the time required for diagnosis and test execution in the laboratories contributes to the delay, since blood samples can remain for several days even on weekends or due to a lack of test kits.In order to depict the actual course of infection over time, the curves would have to show the number of infections that occurred on a certain day instead of the cases reported or recorded on a day. However, since the exact time of infection is rarely known or ascertainable, the RKI sees the date of illness, i.e. the date of the first symptoms, as the most suitable time parameter.However, the date of the illness is only reported in just under two thirds (62.5 percent) of the cases in the reports of the health authorities. In order to get a complete picture of the infection process, the RKI scientists estimate the missing information. To do this, they use common statistical methods to add missing values, so-called “missing data” methods. In addition, they try to use statistical means to more accurately estimate the current number of cases, which is particularly distorted due to the delay times, based on the forecasting for the future called “Nowcasting”.

Decline before the contact block

After an exponential increase, the curve thus determined begins to flatten out after March 9th. As of March 19, the number of new infections has already decreased significantly, i.e. 4 days before the contact bans ordered on March 23, such as exit restrictions, closure of leisure and sports facilities, restaurants etc. The decline hardly accelerated after March 23.

© Photo: RKI
Estimated development of the number of new SARS-CoV-2 cases in Germany (nowcast) due to the partially imputed date of onset of the disease and adjusted for diagnosis and reporting delay with 95% prediction intervals. The dashed vertical lines indicate the start of certain measures on March 9, March 16 and March 23 (updated curve, RKI management report on COVID-19, April 20, 2020, Fig. 6)

The progression of the number of reproductions “R” calculated with improved data shows the low effect of the “shutdown” even more clearly. This started to drop sharply from March 12, dropped to below 1 on March 19 and has been unaffected by contact closures between 0.8 and 1.0 since then.

©  Photo: RKI
Estimation of the effective reproduction number R for an assumed generation time of 4 days. (Robert Koch Institute, Epid.Bulletin 17 | 2020, April 15, 2020, Fig. 4)

The first measures had been taken three days before the beginning of the decline in the number of reproductions, on March 9th. These were measures whose necessity is completely indisputable, such as restricting the ban on major events and appeals, visiting relatives, bars, etc., not celebrating a big party, etc.

Hardly any effects of the measures

At that time, companies had also started to send large parts of their workforce to the home office, as well as shutting down their production and closing their first plants due to delivery bottlenecks and a decline in sales. The population had previously been called upon to adhere to the hygiene recommendations. Obviously, all of this happened with resounding success.The other measures imposed on March 16 already have less visible effects on the spread of the virus. The number of newly infected people began to decrease three days later. However, it is difficult to say whether this would have happened without further measures, just a little delayed. In any case, no significant profit can be derived from the closure of schools and kindergartens or from cultural education institutions, cinemas, sports facilities, swimming pools and other leisure facilities.The closure of many production facilities from mid-March onwards would have had a far greater effect, as adults of all ages had been coming together very closely for some time. However, since the actual number of infected people is significantly higher than the RKI records, the institute’s calculations can only approximate the real magnitude of the decline. However, since the number of identified cases fell significantly despite the constant expansion of the tests, the RKI figures should tend to reflect the course correctly. The actual total number of newly infected people was probably even more pronounced.

“Disproportionate and irresponsible”

Ultimately, the new statistics of the RKI only confirm what can be demonstrated empirically using the example of Sweden. There, the government imposed drastic restrictions. Instead, voluntary compliance with protective measures was used. Elementary schools, shops, restaurants, leisure activities and the like remained open. Nevertheless, the epidemic in the Scandinavian country did not and does not go worse than in Germany.Many experts have warned that the social cost of a shutdown will outweigh the benefits. However, Chancellor Merkel and other leading German politicians are still not impressed by the new calculations by the RKI or the example of Sweden. At the beginning of the epidemic, due to the great uncertainties at the time, there was still an understanding of excessive measures. But now there are findings that could provide a certain all-clear.In view of this and the massive social and economic consequences, maintaining the restrictions not only seems disproportionate, but irresponsible.The federal government is only now planning to equip the health authorities with sufficient personnel to be able to target contact persons of sick people, as in South Korea, and to quarantine them. And together with the state governments, it is taking the easier, populist route for them and will continue to impose strict contact restrictions on the entire population in the coming weeks. We do not seem to have the greatest shortage in Germany in protective masks and toilet paper, but in political will, energy and organizational talent.©                    Sputnik / Tilo grassesJoachim GuilliardJoachim Guilliard studied physics, works full-time as an IT consultant and is active in the peace movement. His view of the corona crisis is based on professional expertise, which also includes statistical procedures, starting with his first jobs in “clinical social medicine” and “geomedicine” at Heidelberg University. He has been running the blog since 2009“Added”. He is the author of numerous specialist articles and co-editor or author of several books.

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