2022-2023 season overview

• The seasonal epidemic activity threshold of 10% positivity in sentinel specimens was first crossed in week 45/2022.   
• Influenza activity had been decreasing across the Region until week 4/2023, following a peak at week 51/2022, but has fluctuated around 25% since week 6/2023.  
• Overall this season, influenza A(H3) viruses have dominated in sentinel primary care specimens, however a higher circulation of A(H1)pdm09 and type B viruses was observed starting from week 50/2022 and week 2/2023, respectively. A similar distribution of A(H1)pdm09 and A(H3) viruses was detected in non-sentinel specimens.   
• 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 in SARI specimens.   

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 2% for week 10/2023. More information on the risk of RSV infections can be found here: https://www.ecdc.europa.eu/sites/default/files/documents/RRA-20221128-473.pdf  

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

• WHO website: https://www.who.int/emergencies/diseases/novel-coronavirus-2019
• ECDC website: https://www.ecdc.europa.eu/en/novel-coronavirus-china

For the European Region, influenza virus positivity in sentinel primary care specimens increased from 24% in the previous week to 26% in week 10/2023. Seasonal activity above the epidemic threshold, which is set at 10%, started in week 45/2022. This is an earlier start of a seasonal influenza epidemic 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 which was earlier than in the four previous seasons: ranging from week 52 (2021/22 season) to 5 (2018/19 and 2019/20). Influenza activity had been decreasing across the Region until week 4/2023, but has fluctuated around 25% since week 6/2023.

Mortality monitoring

EuroMOMO estimates all-cause mortality for the participating European countries, the full report can be found here: https://www.euromomo.eu/

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