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 infection (SARI; countries and areas mostly located in the eastern part of the Region).
1.1) Hospitalized laboratory-confirmed influenza cases – ICUs
For week 2/2022, 8 laboratory-confirmed influenza cases were reported from ICU wards (in France, Sweden and United Kingdom (England)). The patients were infected with both influenza A viruses (n=7) and influenza B viruses (n=1).
Since week 40/2021, more influenza type A (n=193, 95%) than type B (n=10, 5%) viruses were detected. Of 57 subtyped influenza A viruses, 33% were A(H1)pdm09 and 67% A(H3). No influenza B viruses were ascribed to a lineage. Of 155 cases with known age, 67 were 15-64 years old, 41 were 65 years and older, 29 were aged 0-4 years old and 18 were aged 5-14 years old.
1.2) Hospitalized laboratory-confirmed influenza cases – other wards
For week 2/2022, 4 laboratory-confirmed influenza cases were reported from other wards (in Ukraine). Only influenza type A viruses were detected.
Since week 40/2021, 13 influenza type A viruses were detected. All 11 subtyped influenza A viruses were A(H3). Of 13 cases with known age, 8 were 0-4 years old, 4 were 15-64 years old and 1 was aged 5-14 years old.