Weekly influenza overview

Week 17/2021 (26 April-02 May 2021) 


·        Influenza activity remains at or below interseasonal level.


·        Display of data will be updated on a weekly basis until the end of the regular influenza season timing (week 20 data) and on a monthly basis during the interseason.


Qualitative indicators

Information on countries and areas reporting on intensity of activity and geographic spread this week can be seen in respective figures below.


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 2020
© European Centre for Disease Prevention and Control 2020
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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.