Weekly influenza surveillance overview, week 13, 2014

​For week 13/2014:
• Of the 27 countries providing clinical data, Greece and Northern Ireland reported medium intensity and all other countries low intensity.
• A total of 718 sentinel specimens were tested across 25 countries and 121 (17%) were positive for influenza virus. Of these, 117 (97%) were type A, and four (3%) were type B. Of 94 subtyped influenza type A viruses 67 were A(H3) and 27 A(H1)pdm09.
• Five countries reported 92 hospitalised, laboratory-confirmed influenza cases including 51 cases admitted to intensive care units.

Influenza activity is declining towards interseasonal levels. Most of the countries are now reporting low intensity, local or sporadic geographical spread and decreasing trends. The proportion of influenza virus specimens testing positive has substantially decreased this week, with a low level co-circulation of influenza virus subtypes A(H3) and A(H1)pdm09.