[1] Epiconcept, Epidemiol Dept, 47 Rue Charenton, F-75012 Paris, France
[2] Inst Hlth Carlos III, WHO Natl Influenza Ctr, Natl Ctr Microbiol, Natl Influenza Reference Lab, Madrid, Spain
[3] Robert Koch Inst, Dept Infect Dis Epidemiol, Resp Infect Unit, Seestr 10, D-13353 Berlin, Germany
[4] Sorbonne Univ, INSERM, Inst Pierre Louis Epidemiol & Sante Publ IPLESP U, F-75012 Paris, France
[5] Natl Inst Hlth, Dept Infect Dis, Rome, Italy
[6] Bambino Gesu Pediat Hosp, Rome, Italy
[7] Inst Hlth Carlos III, Natl Epidemiol Ctr, Madrid, Spain
[8] Inst Hlth Carlos III, CIBER Epidemiol & Salud Publ CIBERESP, Madrid, Spain
[9] Off Chief Med Officer, Budapest, Hungary
[10] Publ Hlth Agcy Sweden, Stockholm, Sweden
[11] Hlth Serv Execut Hlth Protect Surveillance Ctr, 25-27 Middle Gardiner St, Dublin D01 A4A3 1, Ireland
[12] Natl Inst Publ Hlth & Environm RIVM, Bilthoven, Netherlands
[13] Natl Inst Hyg, Natl Inst Publ Hlth, Warsaw, Poland
[14] Inst Nacl Saude Dr Ricardo Jorge, Dept Epidemiol, Lisbon, Portugal
[15] Croatian Inst Publ Hlth, Zagreb, Croatia
[16] Cantacuzino Natl Med Mil Inst Res & Dev, Bucharest, Romania
[17] European Ctr Dis Prevent & Control ECDC, Gustav III S Blvd 40, S-16973 Solna, Sweden
[18] Natl Reference Ctr Influenza, Robert Koch Inst, Seestr 10, D-13353 Berlin, Germany
[19] Univ Paris Diderot SPC, Unit Genet Mol Virus ARN, Inst Pasteur, CNRS UMR3569, Paris, France
[20] Inst Pasteur, WHO Natl Influenza Ctr, CNR Virus Infect Resp, Paris, France
[21] Inst Nacl Saude Dr Ricardo Jorge, Dept Doencas Infeciosas, Lisbon, Portugal
[22] Carol Davila Univ Med & Pharm, Bucharest, Romania