The World Health Organization European Region (WHO Europe) has stated that, in the week commencing 13 December 2021, the number of flu cases (caused by the influenza virus) detected in the region was above what would normally be expected in the population for the second week in a row, which indicates the flu season epidemic has started. In any given year 5-15% of the population is affected by influenza, leading to between three and five million cases of severe flu and around 650,000 deaths globally.
The main circulating influenza virus in the region has been A(H3N2). In most cases, this will cause mild illness, but in older adults can occasionally lead to severe disease and death. Fewer influenza A(H1N1)pdm09 or influenza B viruses have been detected to date, although the distribution of viruses usually changes over the course of the winter, so this situation may change.
WHO Europe recommends that countries:
- monitor the situation
- vaccinate those at increased risk
- use antivirals on at-risk infected individuals
Source: WHO Europe, 25 December 2021