A subset of countries and areas monitor severe disease related to influenza virus infection by surveillance of
1) hospitalized laboratory-confirmed influenza cases in ICUs or other wards, or
2) severe acute respiratory infections (SARI).
For week 10/2023, 3 398 SARI cases were reported by 17 countries or areas (Albania, Belarus, Belgium, Bosnia and Herzegovina, Georgia, Ireland, Kazakhstan, Lithuania, Malta, Republic of Moldova, Romania, Russian Federation, Serbia, Slovakia, Spain, Türkiye and Ukraine). Of 598 specimens tested for influenza viruses, 15% (n=90) were positive. Of these, influenza type B viruses (n=63, 70%) were detected more frequently than influenza type A viruses (n=27, 30%). Of 10 subtyped influenza type A viruses, 9 (90%) were A(H1)pdm09 and 1 (10%) was A(H3). All 4 type B viruses ascribed to a lineage were B/Victoria. Of 12 countries and areas across the Region that each tested at least 10 specimens, 6 reported positivity rates above 10%: Lithuania (66%), Ukraine (30%), Romania (29%), Serbia (28%), Bosnia and Herzegovina (21%) and Albania (16%).
For the season, 127 554 SARI cases were reported by 27 countries or areas (Albania, Armenia, Belarus, Belgium, Bosnia and Herzegovina, Croatia, Georgia, Germany, Ireland, Kazakhstan, Kyrgyzstan, Lithuania, Malta, Montenegro, North Macedonia, Republic of Moldova, Romania, Russian Federation, Serbia, Slovakia, Spain, Tajikistan, Türkiye, Turkmenistan, Ukraine, Uzbekistan and Kosovo (in accordance with Security Council resolution 1244 (1999))). For SARI cases testing positive for influenza virus since week 40/2022, type A viruses have been the most common (n=3 343, 73%) and of these 2 710 were subtyped: 2 007 (74%) were infected by A(H1)pdm09 viruses and 703 (26%) were infected by A(H3) viruses. All type B viruses (n=310) ascribed to a lineage were B/Victoria.
* Due to a reporting error, the viral breakdown figure cannot be shown at this time.
* 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.