Weekly influenza overview

Week 3/2023 (16 January- 22 January 2023)

 

  • The percentage of sentinel primary care specimens from patients presenting with ILI or ARI symptoms that tested positive for an influenza virus remained above the epidemic threshold (10%) and remained stable at 22% compared to 23% in the previous week.
  • 31 of 38countries or areas reported high or very-high intensity and/or widespread activity indicating high seasonal influenza virus circulation across the Region.
  • Belgium, Finland, Netherlands, Romania, Slovenia and Kosovo (in accordance with UN Security Council Resolution 1244 (1999)) reported seasonal influenza activity above 40% positivity in sentinel primary care.
  • Both influenza type A and type B viruses were detected with A(H1)pdm09 viruses dominating in both sentinel and non-sentinel surveillance systems.
  • Hospitalized patients with confirmed influenza virus infection were reported from ICU, other wards (with mainly influenza type A unsubtyped viruses reported) and SARI surveillance (with mainly influenza A(H1)pdm09 subtype viruses reported). Nine countries or areas reported influenza positivity rates above 10% in SARI surveillance.

 

Qualitative indicators

For week 3/2023, of 38 countries and areas reporting on intensity of influenza activity, 6 reported baseline-intensity (Austria, Iceland, Netherlands, Ukraine, United Kingdom (Northern Ireland) and Uzbekistan), 6 reported low-intensity (Azerbaijan, Belgium, France, Germany, Hungary and United Kingdom (Scotland)), 17 reported medium-intensity (across the Region) and 9 reported high-intensity (across the Region).

 

Of 38 countries and areas reporting on geographic spread of influenza viruses, 3 reported sporadic spread (Azerbaijan, United Kingdom (Northern Ireland) and Uzbekistan), 3 reported local spread (Belarus, Malta and Slovakia), 4 reported regional spread (Austria, Bulgaria, Serbia and Kosovo (in accordance with UN Security Council Resolution 1244 (1999))) and 28 reported widespread activity (across the Region).

 

Please note: 

  • 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 caused by viruses other than influenza, including SARS-CoV-2 and RSV, leading to observed increases in the absence of influenza virus detections.
  • 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.

 

* The administrative boundaries include spatial feature for Kosovo, this designation being without prejudice to position on status, and is in line with United Nations Security Council Resolution 1244 (1999) and the International Court of Justice Opinion on the Kosovo Declaration of Independence.

 

© World Health Organization 2023
© European Centre for Disease Prevention and Control 2023
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The designation employed and the presentation of this material do not imply the expression of any opinion whatsoever on the part of the Secretariat of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers and boundaries.
* The administrative boundaries include spatial feature for Kosovo, this designation being without prejudice to position on status, and is in line with United Nations Security Council Resolution 1244 (1999) and the International Court of Justice Opinion on the Kosovo Declaration of Independence.
Administrative boundaries: © EuroGeographics, © UN-FAO.