Fortnightly Influenza surveillance overview, weeks 21-22 2013

  Week 21/2013 was the first week of inter-season influenza surveillance and ECDC will be producing the overview on every fortnight.
·         For weeks 21 and 22/2013, all participating countries reported low-intensity transmission and almost all reported stable trends.
·         For weeks 21 and 22/2013, six countries tested 19 sentinel specimens, two of which were positive for influenza A(H1N1)pdm09 virus.
·         In addition, 45 non-sentinel source specimens were found to be positive for influenza virus, 19 of which (42%) were type A and 26 (58%) type B.
·         No laboratory-confirmed severe influenza cases have been reported since week 21/2013.
During the first influenza inter-season weeks of 2012–2013, influenza activity was low in Europe.