Weekly influenza update, week 44, 2017

Summary

Intensity of influenza activity in Europe remained at a low level, although sporadic detections or local spread were reported by 40% of the reporting countries.

Overall, 1% of sentinel specimens tested positive for influenza virus.

Data from the 14 countries or regions reporting to the EuroMOMO project indicated that all-cause mortality was at low levels, as expected for this time of the year.

2017/18 season overview

Since week 40/2017, few influenza viruses have been detected in sentinel and nonsentinel

specimens.

Of the viruses subtyped or assigned to a lineage, for detections in both sentinel or nonsentinel surveillance systems, most were identified as A(H3N2) or B/Yamagata viruses. For the northern hemisphere season the A(H3N2) vaccine component is the same as that used in 2015–2016 and only the quadrivalent vaccine contains a B/Yamagata component; both were recommended to be changed for the trivalent vaccine to be used in the next

southern hemisphere season.