A subset of Member States and areas monitor severe disease related to influenza virus infection by surveillance of 1) hospitalized laboratory-confirmed influenza cases in ICUs (11 Member States and areas) or other wards (7 Member States and areas), or 2) severe acute respiratory infection (SARI; 17 Member States and areas, mostly located in the eastern part of the Region).
1.1) Hospitalized laboratory-confirmed influenza cases – ICUs
For week 12/2020, 14 laboratory-confirmed influenza cases in intensive care units (ICUs) were reported by 3 Member States. Among these cases 12 were infected with influenza type A viruses and 2 with influenza type B viruses.
Since week 40/2019, more influenza type A (n=3 543, 90%) than type B (n=373, 10%) viruses were detected. Of 1 228 subtyped influenza A viruses, 58% were A(H1N1)pdm09 and 42% A(H3N2). No influenza B viruses were ascribed to a lineage. The majority of cases were reported from three countries, the United Kingdom (n=1 775), France (n=881) and Spain (n=741). Of 2 141 cases with known age, 49% were 15-64 years old and 37% were 65 years and older.
1.2) Hospitalized laboratory-confirmed influenza cases – other wards
For week 12/2020, 53 laboratory-confirmed influenza cases in wards other than ICUs were reported by 5 Member States. Among these cases 51% were infected with influenza type B viruses and 49% with influenza type A viruses.
Since week 40/2019, more influenza type A (n=5 907, 85%) than type B (n=1 042, 15%) viruses were detected. Of 1 587 subtyped influenza A viruses, 57% were A(H1N1)pdm09 and 43% A(H3N2). No influenza B viruses were ascribed to a lineage. The majority of cases were reported by two countries, Ireland (n=4 132) and Spain (n=2 309). Of 6 948 cases with known age, 43% were 65 years and older and 31% were 15-64 years old.
2. SARI surveillance
For week 12/2020, 616 SARI cases were reported by 7 Member States or areas. Of 295 specimens tested for influenza viruses, 11% were positive for influenza virus. Among these cases, 16 were infected with influenza type A viruses and 2 with influenza type B viruses.
Of the SARI cases tested for influenza viruses since week 40/2019, those testing positive (n=2 877) were mostly infected by type A viruses (56%). Of the 1 356 influenza type A virus infected cases for which subtyping was performed, 61% were A(H1N1)pdm09 and 39% were A(H3N2) viruses. Of the 681 influenza type B viruses ascribed to a lineage, 99% were B/Victoria and 1% were B/Yamagata.
Of 33 588 SARI cases reported since week 40/2019, 33 307 had a recorded age and, of these, 51% were 0–4 years old and 28% were 15–64 years old.
Pooled estimates of all-cause mortality show, overall, normal expected levels in the participating countries; however, increased excess mortality is notable in Italy.
The number of deaths reported to the EuroMOMO project in recent weeks should be interpreted with caution as adjustments for delayed registrations may be imprecise. Furthermore, results of pooled analyses may vary dependent on which countries reported and were therefore included in weekly analyses, despite pooled analyses being adjusted for variation between the included countries and for differences in the local delay in reporting.