• 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: 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 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.

Mortality monitoring

The EuroMOMO 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.