Most countries are now reporting regional or widespread influenza activity, with medium to very high influenza-like illness/acute respiratory infection (ILI/ARI) consultation rates and increasing trends. This is more prominent in Western European countries.
Forty-three per cent of sentinel swabs tested positive for influenza: 74% were type A, and of the type A viruses subtyped, 99% were A(H1N1) 2009.
Since week 40/2010, 1711 severe acute respiratory infection (SARI) cases, including 73 fatal cases, have been reported by eight countries.
The number of severe influenza cases in hospital requiring intensive care is now declining in the UK but are increasing in some other countries.