Weekly influenza surveillance overview, 12 – 18 Dec 2011 (week 50)

During week 50/2011, low influenza activity was notified by all 29 countries reporting.
Of 671 sentinel specimens collected and tested during week 50/2011, 24 (3.6%) were positive for influenza viruses. Of 178 influenza A viruses sub-typed since week 40/2011, 157 (88.2%) were A(H3) viruses.
Since week 40/2011, 94 SARI cases have been reported by five countries. Twenty of them were confirmed influenza cases.
With no evidence of sustained transmission in EU/EEA countries at week 50, the annual influenza season in Europe has yet to start.