Situation update in the European Region

WHO/Europe publishes a weekly electronic bulletin on influenza activity in the Region and performs periodic analysis of surveillance data provided by the 53 WHO European Member States. A preliminary review of data submitted to EuroFlu between week 40/2009 and week 07/2010, compared with historical data where available, shows the following main developments:

• In most countries that reported data, levels of influenza activity are well below recent pandemic peak levels and across most of the European Region, the first wave of pandemic influenza activity is considered to be at an end. 
• Countries in the European Region experienced an early start to the influenza season, and winter-time clinical activity also peaked earlier than it has in several years. 
• The length of the winter pandemic pandemic (H1N1) 2009 wave was generally of similar length, compared with previous seasons. 
• In 19 of 22 countries reporting five or more years of data, the peak clinical consultation rates that were observed during the 2009/2010 pandemic season did not exceed peak clinical consultation rates observed during the previous years. However in several countries, clinical consultation rates did exceed recent historical peaks within some younger age groups. 
• Within the western part of the Region, the geographic progression of the pandemic occurred in a west to east direction. 
• 49 out of 53 Member States reported laboratory-confirmed cases, the large majority of which occurred without complications. 
• 4 572 laboratory-confirmed deaths associated with pandemic (H1N1) 2009 had been reported to WHO/Europe. Although these are underestimates of the actual number of deaths associated with pandemic H1N1 (2009) virus infections, these crude estimates of mortality suggest similar rates to those observed in countries during the winter season in the southern hemisphere. 
• The vast majority of influenza virus detections were pandemic (H1N1) 2009 (99.74% of influenza A subtyped viruses from sentinel sources; N = 19 838). All pandemic (H1N1) 2009 viruses analysed antigenically (N = 1777) or genetically (N = 995) were similar to the vaccine strain and the majority were sensitive to both oseltamivir and zanamivir.