Hospital Surveillance

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).


Laboratory-confirmed hospitalized cases

1.1) Hospitalized laboratory-confirmed influenza cases – ICUs  


For week 47/2022, 2 laboratory-confirmed influenza cases were reported from ICU wards (in Czechia and Ireland). Both were caused by type A viruses neither of which were ascribed to a subtype.


Since week 40/2022, more influenza type A (n=80, 90%) than type B (n=9, 10%) viruses were detected (in Czechia, Ireland, Sweden and United Kingdom (England)). Of 7 subtyped influenza A viruses, 4 were A(H1)pdm09 and 3 were A(H3). No influenza B viruses were ascribed to a lineage. Of 16 cases with known age, 8 were 65 years and older, 7 were 15-64 years old, 1 was 0-4 years old and 0 were 5-14 years old.


1.2) Hospitalized laboratory-confirmed influenza cases – other wards


For week 47/2022, 66 laboratory-confirmed influenza cases were reported from other wards (in Ireland), with influenza type A viruses (97%) being detected more frequently than influenza type B viruses (3%). Of 2 subtyped influenza type A viruses, 1 was A(H1)pdm09 and 1 was A(H3).


Since week 40/2022, 328 influenza type A viruses and 20 influenza type B viruses were detected in cases from Ireland. Of 17 subtyped influenza A viruses, 71% (n=12) were A(H1)pdm09 and 29% (n=5) A(H3). The 348 cases with known age fell in 4 age groups: 121 were 15-64 years old, 112 were 65 years and older, 60 were 5-14 years old and 55 were 0-4 years old.


Hospital unit