[1] Epiconcept, Paris, France
[2] Inst Hlth Carlos III, WHO Natl Influenza Ctr, Natl Ctr Microbiol, Natl Influenza Reference Lab, Madrid, Spain
[3] Inst Hlth Carlos III, CIBER Epidemiol & Salud Publ CIBERESP, Madrid, Spain
[4] Inst Hlth Carlos III, Natl Ctr Epidemiol, Madrid, Spain
[5] Robert Koch Inst, Dept Infect Dis Epidemiol, Resp Infect Unit, Berlin, Germany
[6] Sorbonne Univ, Inst Pierre Louis epidemiol & St Publ IPLESP UMRS, INSERM, Paris, France
[7] HSE Hlth Protect Surveillance Ctr, Dublin, Ireland
[8] Natl Inst Publ Hlth & Environm, Ctr Infect Dis Control, Bilthoven, Netherlands
[9] Inst Nacl Saude Doutor Ricardo Jorge, Epidemiol Dept, Lisbon, Portugal
[10] Inst Salud Publ Navarra IdiSNA, CIBERESP, Pamplona, Spain
[11] Croatian Inst Publ Hlth, Zagreb, Croatia
[12] Publ Hlth Agcy Sweden, Stockholm, Sweden
[13] Semmelweis Univ, Epidemiol & Surveillance Ctr, Natl Lab Hlth Secur, Budapest, Hungary
[14] Cantacuzino Natl Mil Med Inst Res & Dev, Bucharest, Romania
[15] Hlth Promot & Dis Prevent, Infect Dis Prevent & Control Unit IDCU, Msida, Malta
[16] Catholic Univ Louvain, Dept Infect Dis, CHU UCL Namur Site Godinne, Yvoir, Belgium
[17] Robert Koch Inst, Natl Reference Ctr Influenza, Berlin, Germany
[18] Vilnius Univ, Inst Clin Med, Med Fac, Clin Infect Dis & Dermatovenerol, Vilnius, Lithuania
[19] Dr Victor Babes Clin Hosp Infect & Trop Dis, Bucharest, Romania
[20] Univ Hosp Brno, Brno, Czech Republic
[21] Masaryk Univ, Brno, Czech Republic
[22] Consejeria Salud & Consumo, Serv Vigilancia & Salud Laboral, Direcc Gen Salud Publ & Ordenac Farmaceut, Andalucia, Spain
[23] Univ Paris Cite, Ctr Natl Reference Virus Infect Respiratoire CNR, Inst Pasteur, Paris, France
[24] Univ Coll Dublin, Natl Virus Reference Lab, Dublin, Ireland
[25] Nivel, Utrecht, Netherlands
[26] Inst Nacl Saude Doutor Ricardo Jorge, Lab Nacl Referencia Gripe & Outros Virus Resp, Lisbon, Portugal
[27] Direcc Gen Salud publ, Serv Vigilancia & Control Epidemiol, Subdirecc Gen Epidemiol & Vigilancia Salud, Valencia, Spain
[28] Mater Dei Hosp, Dept Child & Adolescent Hlth, Msida, Malta
[29] European Ctr Dis Prevent & Control, Stockholm, Sweden