Is it a mere underreporting of the actual infections or is there a trend reversal in what is now the 5th corona wave? Assessing the current pandemic situation is complicated.
Berlin – For weeks, the nationwide seven-day incidence has been rising every day – but now the curve may be reaching a plateau.
According to the Robert Koch Institute (RKI), the corona incidence of officially recorded cases was 1450.8 on Wednesday and thus only slightly above the value of the previous day (1441.0). The growth has been weakening for days. Will the wave break or could the development have other reasons? What to consider when assessing the pandemic situation.
location in the wave
Federal Health Minister Karl Lauterbach and RKI boss Lothar Wieler do not yet see the peak of the nationwide omicron wave, as they said in Berlin on Tuesday. However, this is still expected for February. However, there are some uncertainties in the estimate. The RKI model, on which the information on the possible peak is based, has not yet included the effect of the virus variant, from which experts expect an increase in the next few weeks: omicron subtype BA.2. According to current knowledge, this variant could be even more transferable and lengthen the omicron wave. The bioinformatician Rolf Apweiler put the current proportion of BA.2 at 10 to 20 percent on Tuesday.
regional situation
According to the RKI, the trend in the seven-day incidence in some federal states continues to rise, while in others there have recently been declining or stagnating numbers. Berlin’s health senator Ulrike Gote said on Tuesday that it could be that the peak in the capital has already been reached or even exceeded. There are indications of this in the laboratory data.
Tests
Laboratories have been reporting new nationwide highs for weeks, both in the number of tests carried out and in the proportion of positive results. In many federal states, more than every second of all samples evaluated is already positive, according to the laboratory association ALM. The positive rate, which has risen to a maximum of around 45 percent nationwide, suggests that many infections are currently not confirmed in the laboratory and therefore do not appear in the official statistics. “The higher the proportion of positives while the number of cases remains high, the higher the number of undetected infected people in a population is calculated (underreporting),” writes the RKI on the subject in the most recent Corona weekly report. For RKI boss Wieler, this does not mean that the perspective on the course of the pandemic is lost because there is a lot of other data on diseases in addition to the pure number of cases. This does not show any breaking of the wave so far.
testing behavior
Experts are eagerly awaiting how people’s testing behavior will develop against the background of discussions about ever-scarcer PCR test capacities. Sometimes very long queues in front of test centers and possible longer waiting times for the result for people who do not belong to the prioritized groups could mean that PCR tests are used less, especially in mild cases. Some people isolate themselves after a positive rapid test, but no longer have their infection clarified by PCR – such cases are then not included in the statistics, in which only PCR evidence is included. According to Wieler, a study on the occurrence of antibodies in the population could probably show the extent of the underreporting after Easter.
disease severity
It was first seen in other countries, now also in Germany: “The proportion of people who suffer from omicron is lower than in Delta,” said Wieler. The proportion of unvaccinated people who came to a hospital with a corona infection is almost twice as high at Delta as at Omikron. But still: “Our data show a significantly higher risk of Covid-19 disease in unvaccinated people.”
old
Experts and politicians are not yet giving the all-clear about the clinical situation because so far it has mainly been younger people who have been infected with Sars-CoV-2. In the case of older people, the values only gradually increase. In the meantime, there seems to be a trend reversal towards a renewed increase in the number of patients in intensive care units. The number of deaths is currently declining, but could increase again, said Wieler. More people in Germany aged 60 and over are unvaccinated than in other countries.
loosening
Opening steps could cause the wave to drag on longer, Lauterbach warned. Last year, the RKI presented a plan with options for withdrawing measures. No such paper has yet been published for the completely different conditions with Omikron. On request, an RKI spokeswoman said: “Of course, the RKI keeps an eye on the development of the pandemic and continuously adjusts recommendations, but ultimately measures are a political decision.”
variants
Even if the omicron wave dies down, it doesn’t have to mean the end of the pandemic. You have to be prepared for surprises in the future, said Apweiler. According to him, other variants will appear that will be very different from the existing ones. Rapid vaccination of the world population with highly effective vaccines and worldwide surveillance through virus genetic analysis is necessary. dpa
