As early as December, the Robert Koch Institute reported a significant increase in flu detections - now the experts are certain: the flu wave has begun in Germany. According to the RKI definition, the start is dated retrospectively to the week ending December 16, 2023, according to a report published on Wednesday evening.
At the National Reference Center for Influenza Viruses at the RKI, samples from patients with symptoms of an acute respiratory infection are regularly examined. According to the experts, to put it simply, the flu wave begins when influenza viruses are detected in every fifth patient sample.
For the weeks between December 18th and 31st, almost 9,000 flu cases confirmed by laboratory analyzes have been transmitted to the RKI, according to the report. However, because of the holidays, the numbers for the last week of December can only be assessed to a limited extent because, among other things, fewer tests are carried out during that time. A total of around 16,600 flu cases have been reported to the institute since October.
Predominant virus type first appeared in 2009 as swine flu
According to the current report, influenza A(H1N1)pdm09 viruses were most recently detected. School-age children and young adults are particularly affected. The RKI writes about this subtype on its website that it first appeared during the 2009 flu pandemic: as so-called swine flu. Since then, it has also circulated seasonally in Germany, most recently significantly in the 2018/19 season.
During influenza waves in which this pathogen dominated, it was observed that very serious illnesses and deaths also occurred in younger adults and children, especially if underlying illnesses were present. “Overall, such severe cases are rare in young people.”
In general, according to the RKI, older people in particular are at risk of becoming seriously ill or dying from the flu. "The number of deaths can vary greatly between flu waves, from several hundred to over 25,000 in the 2017/18 season."
RKI recommends vaccination
Influenza often manifests itself through a sudden onset of illness with fever, muscle aches or headaches, as the RKI informs. “A dry, irritating cough often occurs a little later.” A third of those affected only have mild symptoms, another third have no symptoms at all. Those affected are usually sick for five to seven days.
In 2022, the flu epidemic began in November and therefore unusually early. In the years before Corona, according to the RKI, it usually started in January and lasted three to four months.
“All people for whom Stiko recommends the flu vaccination should get vaccinated as soon as possible if they have not already done so,” says the current report. This includes, among others, all people aged 60 and over, pregnant women, chronically ill people, residents of old people's and nursing homes and people with increased occupational risk.