sharon sanders
Editor-in-Chief & President
<table border="0" cellpadding="0" cellspacing="0" width="100%"><tbody><tr><td class="pageTitle">Weekly Influenza Surveillance Report: influenza season epidemics may be approaching their peak in first affected countries</td></tr><tr><td>27 Feb 2012
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ECDC
The national influenza season epidemics in Europe may be approaching their peak in the first affected countries and remain dominated by A(H3) viruses. The influenza A(H3) and B viruses circulating this season have moved genetically and antigenically away from 2011?2012 seasonal vaccine viruses which has prompted WHO to recommend different vaccine viruses for the 2012-2013 seasonal vaccine. This is reported in the latest edition of the ECDC Weekly Influenza Surveillance Overview.
During week 7/2012 medium intensity was reported by 16 countries while two countries reported high intensity. Geographic spread was reported as widespread by 11 countries, regional by six, local by four and sporadic by six.
Typical for the 2011-2012 influenza season is that it started later than in recent seasons and has been without any clear geographic progression.
Virological surveillance for the period shows that out of 1 873 sentinel specimens tested, 927 (49.5%) were positive for influenza virus. Of the 2 901 influenza viruses detected from sentinel and non-sentinel sources during week 7, 2 788 (96.1%) were type A and 113 (3.9%) were type B. Of the 1 085 influenza A viruses sub-typed, 1 065 (98.2%) were A(H3) and 20 (1.8%) were A(H1)pdm09.
No resistance to the neuraminidase inhibitors (oseltamivir and zanamivir) has been reported so far this season.
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</td></tr><tr><td>
The national influenza season epidemics in Europe may be approaching their peak in the first affected countries and remain dominated by A(H3) viruses. The influenza A(H3) and B viruses circulating this season have moved genetically and antigenically away from 2011?2012 seasonal vaccine viruses which has prompted WHO to recommend different vaccine viruses for the 2012-2013 seasonal vaccine. This is reported in the latest edition of the ECDC Weekly Influenza Surveillance Overview.
During week 7/2012 medium intensity was reported by 16 countries while two countries reported high intensity. Geographic spread was reported as widespread by 11 countries, regional by six, local by four and sporadic by six.
Typical for the 2011-2012 influenza season is that it started later than in recent seasons and has been without any clear geographic progression.
Virological surveillance for the period shows that out of 1 873 sentinel specimens tested, 927 (49.5%) were positive for influenza virus. Of the 2 901 influenza viruses detected from sentinel and non-sentinel sources during week 7, 2 788 (96.1%) were type A and 113 (3.9%) were type B. Of the 1 085 influenza A viruses sub-typed, 1 065 (98.2%) were A(H3) and 20 (1.8%) were A(H1)pdm09.
No resistance to the neuraminidase inhibitors (oseltamivir and zanamivir) has been reported so far this season.
- Read the full report: Weekly Influenza Surveillance Overview 7/2012 (13?19 February 2012)
- ECDC?s Seasonal influenza web pages
- More details on the antigenic and genetic characteristics of circulating viruses can be found in the December report prepared by the Community Network of Reference Laboratories (CNRL) coordination team
- ECDC Director?s statement on influenza, 16 December 2011: While epidemics have not yet started across Europe there is still time to protect yourself against influenza
- ECDC Risk Assessment on Seasonal influenza 2010-2011
- 3 February 2012: Sentinel Surveillance for Severe Influenza in England (United Kingdom)
- 17 January 2012: Application of Virological Risk Assessments: US Department of Health and Human Services (HHS) sponsors clinical trials of a vaccine targeted to a novel A(H3N2)v influenza strain
- 17 January 2012: The importance of analyses of antigenic match and monitoring influenza vaccine effectiveness
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