Weekly influenza overview

Week 41/2021 (11 - 17 October 2021)

  • Influenza activity was low throughout the European Region, though Croatia and Kyrgyzstan experienced early influenza activity related to A(H3) circulation. 
  • Influenza viruses were detected sporadically in specimens from persons with respiratory illness presenting to medical care with a slight increase compared to the previous week. 
  • Both influenza A and B type viruses were detected, with A(H3) subtype predominating. 
  • Type A virus infection was reported for two patients in intensive care units. Seven patients with SARI in hospital settings were infected with A(H3) viruses. 
Qualitative indicators

For week 41/2021, of 36 Member States and areas reporting on intensity of influenza activity, 35 reported baseline or low intensity. Luxembourg reported high intensity due to high ILI and ARI rates but no influenza detections.

Of 35 Member States and areas reporting on geographic spread, all reported no or sporadic activity


Please note: 

  1. Assessment of the intensity of activity indicator includes consideration of ILI or ARI rates. These ILI or ARI rates might be driven by respiratory infections other than influenza, including SARS-CoV-2, leading to observed increases in the absence of influenza virus detections
  2. Assessment of intensity and geographic spread indicators includes consideration of sentinel and non-sentinel influenza virus detection data. Non-sentinel influenza virus detections, often higher, might translate into reporting of elevated geographic spread even in the absence of sentinel detections. 
© World Health Organization 2021
© European Centre for Disease Prevention and Control 2021
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