Weekly influenza surveillance overview, 4 May 2012 - week 17

Surveillance report
The weekly/bi-weekly influenza surveillance overview is a collection of timely and relevant information regarding influenza activity in Europe. It provides key statistical data on a variety of issues including the following: sentinel surveillance of influenza-like illness and acute respiratory illness; virological surveillance; hospital surveillance of severe acute respiratory infection (SARI); mortality surveillance and qualitative reporting. An up-to-date report is available on Fridays.

Executive Summary

The reported national influenza trends indicate that influenza season is now approaching its end in Europe

The 2011–2012 influenza season started late and has been without any clear geographic progression. During week 17/2012, almost all countries reported low intensity and decreasing or stable trends.

Virological surveillance for week 17/2012 shows that of the 162 sentinel specimens tested, 19.1% were positive for influenza virus, continuing the downward trend observed since week 8/2012. As expected towards the end of the season, the proportion of B viruses continued to increase.

The A(H3N2) influenza viruses examined at the WHO Collaborating Centre in London show increasing evidence of an imperfect match between the circulating viruses and the current relevant vaccine antigen. This supports the WHO and EMA recommendation to modify the trivalent vaccines for the 2012/2013 Northern Hemisphere season.

Publication file

120504-SUR-WISO.pdf

English (2.9 MB - PDF)

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