Influenza virus characterization - Summary Europe, May 2022 - ISS-G20 Laboratorium Repository

This is the sixth report for the 2021-2022 influenza season. The March 2022 characterization report, gave a breakdown of influenza detections across the World Health Organization (WHO) European Region reported to TESSy up to week 13/2022. As of week 20/2022, 133 099 detections had been reported (a rise of over 42 000 since week 13/2022) resulting from extended late season influenza activity. Of these 133 099 detections, 98% were type A viruses, with A(H3N2) (92%) dominating over A(H1N1)pdm09 (8%), and 2% type B of which only 111 were ascribed to a lineage, with all but four being B/Victoria. This represents a large increase (132 190, 146-fold) in detections compared to the 2020-2021 season, on the back of a great increase (1 724 858, 194%) in the number of samples tested. However, while there have been clear indications of an influenza epidemic in 2021-2022 with the epidemic threshold of 10% positivity within sentinel specimens having been crossed for 17 weeks as of week 20/2022 (unlike in 2020-2021), numbers of detections are reduced compared to earlier seasons (e.g., 19% reduced compared to 2019-2020). The increased testing but reduced number of influenza detections is undoubtedly related to the emergence of SARS-CoV-2 and measures introduced to combat it.

Entire content available on: https://www.ecdc.europa.eu/en/publications-data/influenza-virus-characterization-summary-europe-may-2022