During week 9, 19 of 27 countries reporting indicated high/medium-intensity transmission and wide geographic spread. Only two countries reported increasing trends compared to six in week 8. Of the 18 countries that reported decreasing trends, five did so for the first time since the beginning of influenza transmission this season.
Virological surveillance shows that the overall proportion of influenza-positive cases among sentinel specimens continues to remain high (54%), but it has decreased from the peak observed in early February.
Since week 40/2012, an even distribution of influenza virus types has been observed, 50% each for type A and type B viruses. After a sustained increase between weeks 02 and 07/2013, the proportion of A(H1)pdm09 has remained at around 60% of A viruses with subtyping information.
On the 8 February 2013, ECDC published its annual risk assessment for seasonal influenza 2012-13 based on data up to week 03/2013.