Season overview
  • The seasonal epidemic activity threshold of 10% positivity in sentinel specimens was first crossed in week 45/2022.      

  • Following a peak at week 51/2022 with 39% positivity, influenza activity had been decreasing across the Region until week 4/2023 when it reached 21% positivity before rising again to fluctuate around 25% positivity between weeks 6 and 11/2023 before decreasing below 10% positivity in week 16/2023.      
  • Overall this season, influenza A(H3) viruses have dominated in sentinel primary care specimens, however higher circulation of A(H1)pdm09 and type B viruses was observed starting from week 50/2022 and week 2/2023, respectively. In non-sentinel specimens, higher circulation of A(H1)pdm09 (55%) than A(H3) viruses (45%) was detected.      
  • Both influenza type A and type B viruses have been detected in hospitalized patients in ICU and other wards and influenza A(H1)pdm09 viruses have dominated among SARI patients.   
  • Virus type and subtype prevalence by country and surveillance system has been variable across the season.     
  • The B/Yamagata viruses sporadically detected and reported by different countries have been further investigated and were proven to be LAIV related detections. 


Other news 


           RSV is another respiratory virus that causes acute respiratory disease, mainly among young infants and the elderly, often mild but frequently severe among children less than 1 year of age and frail elderly. High levels of RSV have been circulating across the Region since week 40/2022, with overall positivity amongst patients in primary care with acute respiratory illness decreasing after a peak at 18% positivity in week 47/2022 to <1% for week 20/2023. More information on the risk of RSV infections can be found here.


For information about the SARS-CoV-2 situation in the WHO European Region visit:

           WHO website:

           ECDC website:

Influenza positivity

For the European Region, influenza virus positivity in sentinel primary care specimens decreased from 4% in the previous week to 2% in week 20/2023, falling below the epidemic threshold of 10%. Seasonal activity started in week 45/2022 when positivity crossed above the epidemic threshold set at 10%. The current seasonal influenza epidemic started earlier than in the four previous seasons, ranging from week 47 (2019/20 season) to 49 (2021/22 season). Positivity reached a peak in week 51/2022 at 39% which was earlier than in the four previous seasons, ranging from week 52 (2021/22 season) to 5 (2018/19 and 2019/20). Across the Region, influenza activity decreased to 21% up to week 4/2023, then fluctuated around 25% between weeks 6 and 11/2023 and decreased thereafter.


External data sources

Mortality monitoring


The EuroMOMO report can be found here:


Please refer to the EuroMOMO website for a cautionary note relating to interpretation of these data.