Syndromic surveillance data
Of the countries and areas in which thresholds for ILI activity are defined, countries in eastern (n=3; Azerbaijan, Georgia and Kazakhstan), northern (n=4; Denmark, Estonia, Latvia and Lithuania), southern (n=5; Croatia, Greece, Romania, Slovenia and Türkiye) and western (n=7; Austria, Belgium, Czechia, Hungary, Luxembourg, Poland and Switzerland) areas of the European Region reported activity above baseline levels.
Of the countries and areas in which thresholds for ARI activity are defined, countries in eastern (n=2; Kazakhstan and Ukraine), northern (n=2; Latvia and Lithuania), southern (n=3; Bulgaria, Romania and Slovenia) and western (n=1; Czechia) areas of the European Region reported activity above baseline levels.
Assessment of the syndromic surveillance data of ILI or ARI rates might be driven by respiratory infections other than influenza virus, including SARS-CoV-2, leading to observed increases in the absence of influenza virus detections. The thresholds mentioned are related to the Moving Epidemic Method (MEM) and based on historic ILI/ARI incidence data.
Viruses detected in sentinel-source specimens (ILI and ARI)
For week 10/2023, 939 (26%) of 3 671 sentinel specimens tested positive for an influenza virus; 72% were type B and 28% were type A. Of 186 subtyped A viruses, 93% were A(H1)pdm09 and 7% A(H3). All 184 type B viruses ascribed to a lineage were B/Victoria. Of 33 countries and areas across the Region that each tested at least 10 sentinel specimens in week 10/2023, 21 reported a rate of influenza virus detections above 10% (median 26%; range 13% - 68%): Romania (68%), Hungary (52%), France (52%), Slovenia (46%), Armenia (35%), Spain (35%), Denmark (34%), Serbia (33%), Kosovo (32%), Luxembourg (29%), Ukraine (26%), Germany (25%), Slovakia (24%), Poland (24%), Republic of Moldova (23%), Austria (23%), Netherlands (21%), Norway (21%), Switzerland (19%), Italy (16%) and Ireland (13%).
For the season to date, 23 541 (24%) of 100 053 sentinel specimens tested positive for an influenza virus. More influenza type A (n=18 332, 78%) than type B (n=5 209, 22%) viruses have been detected. Of 14 934 subtyped A viruses, 9 820 (66%) were A(H3) and 5 114 (34%) were A(H1)pdm09. All 1 564 influenza type B viruses ascribed to a lineage were B/Victoria (70% of type B viruses were reported without a lineage).
Details of the distribution of viruses detected in non-sentinel-source specimens are presented in the virus characteristics section.
External data sources
Influenzanet collects weekly data on symptoms in the general community from different participating countries across the EU/EEA. Please refer to the website for additional information for week this week.
* 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.