The latest development is causing "great concern". Wieler cited negligence in adhering to the rules of conduct as the reason for the increase. Wieler said it was not known whether this was the beginning of a possible second wave, but it could be.

Until some time ago, the RKI head explained, it had been possible to keep the number of cases stable with 300 to 500 new cases reported daily. In the meantime, things have changed: On Friday, for example, 815 cases were added, on Saturday more than 700 and on Tuesday more than 600. After weekends, the numbers are always lower at first.

In contrast to the past weeks with individual large outbreaks such as the Tönnies slaughterhouse, the situation is currently diffuse, RKI expert Ute Rexroth, head of the Surveillance Department, described. "Unfortunately many people are affected." Increases in the number of cases in different municipalities and communities were observed. All over Germany more people are infected again. There are transmissions "really everywhere": at family celebrations, meetings with friends, at work, in shared accommodation, old people's homes and health care facilities, where severe cases are to be expected. Even if there are cases of people returning home from abroad: the majority of those affected have contracted the disease in Germany, Rexroth said.

The RKI believes that prevention is necessary to prevent the virus from spreading again rapidly and uncontrollably and to prevent the health authorities from having to chase after outbreaks. "We can only do this together," said Wieler. The further development is "in our hands". He appealed to German citizens to keep to the so-called aha-rules (distance, hygiene, everyday mask). These rules also apply outdoors and on vacation, as Wieler emphasized. Masks must be worn correctly, i.e. over mouth and nose.

It would be problematic if the virus was given the chance to spread: To throw thousands of wild parties is "reckless" and also "negligent", Wieler said. Young people could infect their parents and grandparents, he warned. With this, the RKI president was obviously alluding to incidents such as the illegal parties of young people in the park Hasenheide in Berlin-Neukölln, which had been disbanded by the police over the weekend.

"We are in the middle of a rapidly developing pandemic", Wieler concluded. Some countries that seemed to have the epidemic already under control recorded rising case numbers again, such as Australia, Japan and Spain. In these countries, the decisive factor is that individual protection measures are no longer being followed so well, particularly among younger people. Israel is also experiencing a "serious relapse".