Week 20/2021 (17-23 May 2021)
· Influenza activity remained at interseasonal level.
· This is the last weekly update of the influenza season and updates during the interseason period (weeks 21-39) will be on a monthly basis.
Information on countries and areas reporting on intensity of activity and geographic spread for this week can be seen in the respective figures below.
- 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
- 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.
© European Centre for Disease Prevention and Control 2021
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