For a long time, the incidence was the measure of all things when it came to assessing the incidence of infections. Now other values are also coming into focus. Is that the end of the incidence? It’s still too early for that, say experts.
In the past few months, the incidence has been the main indicator of the pandemic: is the value falling, falling or rising? Is it possible to relax, is the catering industry allowed to open or is there a threat of further tightening of lockdowns? The measures of the federal emergency brake, which expired in June, were strictly linked to the incidence. It is understandable that for many, looking at the number every day is almost as much a part of it as the weather forecast.
But the value that is calculated from the number of new infections reported within seven days per 100,000 inhabitants has never been undisputed. Critics argue that the incidence depends on other factors, including the number of tests and vacation time, and does not differentiate based on where the infections take place. A local, self-contained outbreak, for example in a student residence, is easier to contain than numerous, diffuse individual cases. However, both scenarios cause the incidence to increase equally.
Proponents, on the other hand, argue that the value is an early indicator that allows a possible overload of clinics and intensive care units to be foreseen before it occurs. If, on the other hand, only the utilization of the intensive care units were considered – as demanded by some incidence critics – an impending overload might not be recognized in good time.
Clinics come into focus
The debate about the pros and cons of incidence is old, but has picked up speed again with the increasing vaccination rate in Germany. In addition to the incidence, the Robert Koch Institute (RKI) now wants to take greater account of the occupancy of hospitals when it comes to assessing the pandemic.
Federal Health Minister Jens Spahn (CDU) signed a new ordinance on Monday that obliges clinics to provide more details about Covid 19 patients – including vaccination status and age. The clinics should also collect data on how many patients with Covid-19 are admitted to the normal wards. So far, the main focus has been on the occupancy of the intensive care beds.
“With increasing vaccination rates, the incidences become more and more uncoupled from medically relevant variables such as mortality and hospital admissions,” explained Christoph Rothe, head of the Department of Statistics at the University of Mannheim, when asked by the Science Media Center (SMC). “This effect can be observed especially in England, where the sharp rise in infection numbers is currently accompanied by a comparatively low increase in hospital occupations and deaths.” For Germany it therefore “makes sense” to consider more detailed data from the hospitals in the future, “said Rothe.
Federal Minister of Health Jens Spahn (CDU) made a similar statement: “Since the risk groups at risk are vaccinated, a high incidence does not automatically mean an equally high level of stress in the intensive care beds,” said Spahn. The incidence is becoming increasingly less meaningful. The data from the clinics can also be used to estimate how well the vaccinations are working.
Incidence remains an “important parameter”
However, the federal government does not want the regulation to be understood as a change of course or a departure from the seven-day incidence. The incidence “is and will remain an important parameter,” said a health ministry spokesman on Monday. But why is that so?
Here, too, the vaccination quota comes into play. There has been great progress: around 59.2 percent of the population have received at least one vaccination dose, 44.6 percent have full vaccination protection. But how there are big differences between the individual age groups
While almost three out of four people in the over-60s are fully immunized (72.8 percent), in the U-18 age group it is just under two out of 100 (1.8 percent). The majority of the elderly are thus well protected from infections and severe courses, but the virus can spread well in young sections of the population, as it has already done
From the point of view of the SPD health expert Karl Lauterbach, a complete departure from the incidence at the present time creates several problems, as he writes. If you only look at the number of hospital admissions, there is a risk of children being infected and a “wave” of long-covid patients, according to Lauterbach.
The vaccine from Biontech / Pfizer may be used for children between 12 and 17 years of age. On the part of the Standing Vaccination Commission (Stiko), however, there is no general recommendation for this age group, but only for children with certain previous illnesses. In practice, this means that healthy children are rarely vaccinated against the coronavirus. In principle, however, they also have a lower risk of severe courses.
Experts are also concerned about high incidences and case numbers. The more cases and transmissions there are, the greater the likelihood that a significant mutation will occur that could make the virus more contagious or less sensitive to vaccines, for example.
“Dreiklang” for autumn
The incidences are still low, but experts expect the number of cases to rise again towards autumn. Christian Karagiannidis, head of the ECMO center at the Cologne-Mehrheim Clinic, advocated a “triad” as a guideline for the pandemic – consisting of incidence, intensive occupancy and new admissions as well as new hospital admissions. These three factors would help to “assess the situation more precisely” and are “extremely valuable” for autumn, according to Karagiannidis.
Hajo Zeeb, prevention expert at the Leibniz Institute in Bremen, also emphasized the benefit of the incidence to the SMC, at least for the coming months: “In my opinion, it will continue to make sense to carry out infection monitoring based on incidences in autumn and winter “said Zeeb. “After that, it will have to be checked whether it can be dispensed with.”