Influenza activity continued to increase across Europe, concludes the Weekly Influenza Surveillance Overview, Week 5, 2013. The epidemics may have passed their peaks in a few countries, although some countries experienced a resurgence of influenza-like-illness rates.
During week 5, 19 of the 29 countries reporting have indicated high/medium-intensity transmission and wide geographic spread. Twenty-two countries reported increasing trends in influenza activity.
Virological survellance shows that the proportion of influenza-positive cases among sentinel specimens was high (55%), representing an increase from 52% on week 4/2013.
Since week 40/2012, the proportions of influenza A and B viruses have remained similar (51% vs. 49%), but among type A viruses, the percentage of A(H1)pdm09 has continued to increase (64%), compared to 52% in week 2/2012.