# 5308
The end-of-week flu surveillance reports continue to come in, with the ECDC’s week 5 summary showing that medium to high levels of influenza continue in a number of European countries.
As depicted in the graph below,the 2009 H1N1 virus continues to lead the pack in Europe by a wide margin, in stark contrast to North America where H3N2 has comprised the bulk of this year’s flu samples.
A few highlights from this week’s report:
11 February 2011
Main surveillance developments in week 5/2011 (31 Jan – 06 Feb 2011)
- Most European countries continue to report medium to high influenza-like illness/acute respiratory infection consultation rates and widespread activity. Increasing trends are mainly observed in central, eastern and southern Europe whereas countries in western and northern Europe are reporting unchanging or declining trends.
- The proportion of influenza-positive sentinel specimens is gradually decreasing, having now reached 46%.
- 67% of influenza virus detections in week 5/2011 were type A, 33% were type B. In nine countries, type B detections exceeded those of type A. More than 98% of subtyped influenza A viruses were A(H1N1)2009.
- In week 5/2011, ten countries reported 194 all-cause SARI and confirmed hospitalised influenza cases, the latter mostly due to influenza A(H1N1)2009.
- Numbers of influenza infections with severe outcome have declined in western European countries (Denmark, France, the Netherlands, Ireland and the UK). However, there is now considerable uncertainty on information concerning severe cases in central and eastern European countries.
Virological surveillance
(excerpt)
Since week 40/2010, Ireland, Italy, Norway, Spain and the UK have reported antiviral resistance data to TESSy (Table 3). Twenty-three (3.2%) of 720 influenza A(H1)2009 viruses tested for susceptibility to neuraminidase inhibitors were resistant to oseltamivir, but remained sensitive to zanamivir. All the resistant viruses carried the H275Y substitution.
Nineteen resistant viruses were from patients with known exposure to antivirals. While for seven of these patients, no exposure to neuraminidase inhibitors was reported, 12 had been exposed to oseltamivir.
