Weekly influenza update, week 10, March 2018

data graph map
Period: 05 Mar 2018 - 11 Mar 2018

Influenza viruses continue to circulate widely in the Region, apart from some eastern European countries that have only recently reported increased activity. Similar to the previous week, 50% of the individuals sampled from primary healthcare settings tested positive for influenza virus, despite the peak rate for the Region occurring in week 05/2018. Both influenza virus types A and B were co-circulating with a higher proportion of type B viruses and with B/Yamagata continuing to be the dominant lineage. Similar proportions of influenza type A and B viruses were reported in patients admitted to ICU, while the majority of severe cases reported this season have been due to influenza type B and occur in persons above the age of 15 years.

Influenza in Europe, week 10, 2018

Download

Thumbnail

Summary

  • Influenza viruses continue to circulate widely in the Region, apart from some eastern European countries that have only recently reported increased activity.
  • Similar to the previous week, 50% of the individuals sampled from primary healthcare settings tested positive for influenza virus, despite the peak rate for the Region occurring in week 05/2018.
  • Both influenza virus types A and B were co-circulating with a higher proportion of type B viruses and with B/Yamagata continuing to be the dominant lineage.
  • Similar proportions of influenza type A and B viruses were reported in patients admitted to ICU, while the majority of severe cases reported this season have been due to influenza type B and occur in persons above the age of 15 years.

2017/18 season overview 

  • For the region overall, the majority of influenza viruses detected were type B, representing a high level of circulation of influenza B viruses compared to recent seasons. B/Yamagata lineage viruses have greatly outnumbered those of the B/Victoria lineage.
  • Different patterns of dominant type and A subtypes were observed between the countries of the Region, which may be due to differences in relative weights of information being derived from sentinel, non-sentinel and severe influenza case sources of information.
  • Of the type A virus detections from sentinel sources, the majority of which were subtyped. A(H1N1)pdm09 viruses have outnumbered A(H3N2) viruses. In non-sentinel sources, more A(H3N2) viruses were reported than A(H1N1)pdm09 viruses.
  • While low in number, 57% of A(H3N2) viruses belong to clade 3C.2a and 48% of B/Victoria viruses belong to a subclade of clade 1A viruses that are antigenically distinct from the current trivalent vaccine component.
  • The majority of severe cases reported this season are due to influenza type B and occur in persons above the age of 15 years.
  • Mortality from all causes from data pooled across 17 EU countries and regions that reported to euroMOMO (http://www.euromomo.eu/) remains elevated in some countries, while it is declining in others.
  • Interim results from 5 European studies indicate that influenza vaccine effectiveness was estimated to be similar to that in recent years. 

See all weekly influenza updates

Data

Weekly influenza update, week 19, May 2019

infographic -

Data

Weekly influenza update, week 18, May 2019

infographic -

Data

Weekly influenza update, week 17, April 2019

infographic -

Data

Weekly influenza update, week 16, April 2019

infographic -

Data

Weekly influenza update, week 15, April 2019

infographic -