[1] Univ Florence, Anna Meyer Childrens Hosp, Dept Hlth Sci, Paediat Infect Dis Unit, Florence, Italy
[2] Univ Florence, Anna Meyer Childrens Hosp, Dept Paediat Med, Florence, Italy
[3] Univ Milan, Luigi Sacco Hosp, Dept Paediat, Paediat Infect Dis Unit, Milan, Italy
[4] Bambino Gesu Pediat Hosp, Stefania Bernardi Acad Dept Pediat DPUO, Unit Immune & Infect Dis, Ist Ricovero & Cura Carattere Sci, Rome, Italy
[5] Bambino Gesu Pediat Hosp, Paola Zangari Acad Dept Pediat DPUO, Res Unit Clin Immunol & Vaccinol, Ist Ricovero & Cura Carattere Sci, Rome, Italy
[6] Univ Genoa, Policlin San Martino Hosp, Infect Dis Unit, Genoa, Italy
[7] Univ Padua, Dept Women & Child Hlth, Padua, Italy
[8] Univ Turin, Regina Margherita Childrens Hosp, Paediat Infect Dis Unit, Turin, Italy
[9] Univ Milan, Ist Ricovero & Cura Carattere Sci, Ca Granda Osped Maggiore Policlin Fdn, Paediat Highly Intens Care Unit,Dept Pathophysiol, Milan, Italy
[10] Univ Parma, Pietro Barilla Childrens Hosp, Paediat Dept, Parma, Italy
[11] Univ Naples Federico II, Dept Translat Med Sci, Paediat Unit, Naples, Italy
[12] Univ Brescia, Dept Clin & Expt Sci, Brescia, Italy
[13] Univ Pavia, Ist Ricovero & Cura Carattere Sci, Dept Internal Med & Therapeut, Policlin S Matteo Fdn, Pavia, Italy
[14] Univ Modena & Reggio Emilia, Dept Med & Surg Sci, Paediat Hematooncol Unit, Modena, Italy
[15] Osped Microcitem, Dept Paediat, Cagliari, Italy
[16] Santa Chiara Hosp, Dept Paediat, Trento, Italy
[17] St Orsola Hosp, IRCCS Sci Inst Res & Healthcare, Paediat Unit, Bologna, Italy
[18] Univ Hosp Policlin Giovanni XXIII, Paediat Infect Dis Unit, Bari, Italy
[19] Univ Milan, Niguarda Hosp, Dept Paediat, Milan, Italy
[20] Univ Parma, Pietro Barilla Childrens Hosp, Dept Med & Surg, Parma, Italy
[21] Salesi Childrens Hosp, Dept Mother & Child Hlth, Ancona, Italy