Severity

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 (9 Member States and areas) or other wards (7 Member States and areas), with 6 Member States and areas reporting both 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

Among laboratory-confirmed influenza cases reported in ICUs for week 03/2020 (n=127), influenza type A viruses (n=116, 91%) were detected more frequently than influenza type B viruses (n=11, 9%).

Since week 40/2019, more influenza type A (n=1 884, 94%) than type B (n=112, 6%) viruses were detected. Of 594 subtyped influenza A viruses, 63% were A(H3N2) and 37% A(H1N1)pdm09. No influenza B viruses were ascribed to a lineage. Of 534 cases with known age, 50% were 15-64 years old and 39% were 65 years and older.

1.2) Hospitalized laboratory-confirmed influenza cases – other wards

Among laboratory-confirmed influenza cases reported in wards other than ICUs for week 03/2020 (n=190), influenza type A viruses (n=169, 89%) were detected more frequently than influenza type B viruses (n=21, 11%).

Since week 40/2019, more influenza type A (n=3 321, 94%) than type B (n=218, 6%) viruses were detected. Of 724 subtyped influenza A viruses, 73% were A(H3N2) and 27% A(H1N1)pdm09. No influenza B viruses were ascribed to a lineage. Of 3 539 cases with known age, 47% were 65 years and older and 28% were 15-64 years old.

2. SARI surveillance

For week 03/2020, 1 481 SARI cases were reported by 14 Member States or areas. In total, specimens from 360 SARI cases were tested for influenza viruses and 43% (n=156) were positive for influenza virus: 56% (n=88) type A and 44% (n=68) type B.

Of 16 295 SARI cases reported since week 40/2019, 16 101 had a recorded age and, of these, 58% were 0–4 years old and 22% were 15–64 years old. Of the SARI cases tested for influenza viruses since week 40/2019 (n=3 648) those testing positive (n=727) were mostly infected by type B viruses (n=461, 63%). Of the 242 influenza type A virus infected cases for which subtyping was performed, 76% (n=185) were A(H1N1)pdm09 and 24% (n=57) were A(H3N2) viruses. Of the 162 influenza type B viruses ascribed to a lineage, 96% (n=155) were B/Victoria and 4% (n=7) were B/Yamagata.

Mortality monitoring

For week 03/2020, the EuroMOMO project received data from 21 countries or areas that were included in pooled analyses. Pooled estimates of all-cause mortality were within the expected range for the time of year.