Heinsberg-study: some 20 percent of the Corona Infected show no symptoms
According to official data, over 160,000 people in Germany have so far with the novel Coronavirus SARS-CoV-2 plugged in. However, according to a study, the number of Infected could be estimated that almost two million. In addition, scientific research shows that about 20 percent of those infected have no symptoms.
The district of Heinsberg in the government district of Cologne in North Rhine-Westphalia is regarded as a focal point for the Coronavirus. After a carnival session in mid-February it came to a early and massive spread of the pathogen. In the framework of the so-called Heinsberg study, a research team, among other things, the mortality rate of the infection was determined. This is clearly demonstrated lower than anticipated, as was already the first results. Now, the study were presented results to the Public.
Important findings for the country as a whole
“In the district of Heinsberg was there earlier than all other places in Germany, a large number of people infected with the Corona Virus. The district of Heinsberg is the only region, from which important insights for the whole of Germany can be derived,“ said the North Rhine-Westphalian Prime Minister, Armin Laschet, in a communication to the first intermediate results of the so-called Heinsberg-study.
Now the results of the study have been published in advance and are now presented to the science and to the Public. A publication in a professional journal with Peer-Review process will follow.
According to a communication by a research team led by Prof. Dr. Hendrik Streeck and Prof. Dr. Gunther Hartmann of the University of Bonn in the framework of the study had interviewed in the village of Gangelt, in the district of Heinsberg, a large number of the inhabitants, that samples be taken and analyzed.
Proportion of deaths among the Infected
In the centre of the study, the mortality rate of the infection (the so-called infection, mortality, English: infection fatality rate, IFR) that indicates the proportion of deaths among the Infected is.
This must be distinguished from the case mortality (the case fatality rate, CFR). As it says in the message, the IFR for various reasons, the more reliable parameters, and the determination of which is required internationally for SARS-CoV-2.
“Our data can now be used for the first Time is very well appreciated, how many people have been infected after an outbreak of the event”, explains study leader Prof. Dr. Hendrik Streeck, Director of the Institute for Virology at the Universitätsklinikum Bonn.
“In our study, the 15 percent for the municipality were Gangelt. The total number of Infected Infection rate (IFR) can be determined. It is for SARS-CoV-2 for the outbreak in the commune of Gangelt 0.37 per cent,“ says the expert.
The dark figure is more than ten times as high as the number of reported cases
With the IFR based on the number of deceased for other places with the other infection rates to estimate, how many people is there in total. The comparison of this number with the number of officially reported Infected then leads to the so-called dark figure.
According to the figures, this is in Gangelt approximately 5-fold higher than the officially reported number of positively tested persons. If you put a high statement about the number of nearly 6,700 SARS-CoV-2-associated death cases in Germany, an estimated total of around 1.8 million Infected would be.
This dark figure is, according to the Bonn Uni by a factor of 10 larger than the total number of officially reported cases (162.496 on 03.05.2020, 07:20 PM).
“The results can be used to improve model calculations of the propagation behavior of Virus more – so far, the data basis is relatively uncertain,” explains Co-author Prof., Dr. Gunther Hartmann, Director of the Institute for Clinical chemistry and Clinical pharmacology at the University hospital in Bonn.
According to the researchers, the study also gives important clues for further research on SARS-CoV-2, such as the risk of infection depending on age, gender and pre-existing conditions, the higher the severity of the disease under the special conditions of a massive infection event, such as in Gangelt, or to the risk of infection within families.
Approximately every fifth infection without noticeable symptoms
The symptom description is also an aspect of the study. The infection most striking symptom complex is the Professor Streeck, described above, are smell and taste loss.
Furthermore, a total of 22 percent of them were in Gangelt of all persons infected with no symptoms. It is noticed that people who have participated in the carnival meeting, they had frequent symptoms.
“To find out if here is the physical proximity to other meeting participants and an increased formation of Droplets by loud Talking and Singing have contributed to a stronger progression of the disease, we plan further investigation in cooperation with specialists for Hygiene,” explains Prof. Hartmann.
“That, apparently, every fifth infection progresses without noticeable symptoms of the disease, suggests that you are Infected, leaving the Virus and thus infect others can, not sure on the Basis of identifiable symptoms of a disease can identify with,” says Prof. Martin Exner, Director of the Institute for Hygiene and public health and Co-author of the study.
According to the health experts, confirm the importance of distance and hygiene rules in the Corona of a pandemic. “Everyone is supposedly Healthy, meet us, can unwittingly carry the Virus. We need to make us aware of us in that behavior,“ says Prof. Exner.
It also showed that in the examined multi-person households, the risk for the contagion of another Person, was surprisingly low. “The infection rates are in children, adults and Elderly are very similar and do not depend obviously on the age,” explains Prof. Streeck. Between the sexes there were no significant differences.
The Test detects antibodies
For the study, a total of 600 randomly selected households in Gangelt were contacted and asked to participate. 919 study participants from 405 households were from the 30. March to 6. April, six weeks after the outbreak of the infection in Gangelt interviewed and tested. The researchers took pharyngeal swabs and blood samples.
According to the figures of the infection in the first week or two of the PCR Test, which detects the “genetic fingerprint” of SARS-CoV-2 is in the acute phase, very reliable. Two or three weeks after infection the immune system called antibodies against the pathogen, which recognizes the ELISA Test.
“The combination of PCR – and ELISA-Test, we can capture both acute and past infections,” explains Hartmann. Preliminary studies have shown that the ELISA Test is wrong in about one percent of the investigations carried out, and a false recent infection shows.
“In a high percentage of Infected as in Gangelt, this measurement occurs technical uncertainty factor in the Background,” says Prof. Hartmann.
Currently planned Germany-wide studies, with an estimated infection rate of about one to two percent of this measurement is technical Uncertainty but a Problem.
“What are the conclusions to be drawn from the study results, depends on many factors, which go beyond a purely scientific view,” says Prof. Streeck. “The evaluation of the findings and the conclusions for the concrete decisions are the responsibility of the company and the policy.” (ad)