[1] Univ Padua, Dept Pediat, I-35100 Padua, Italy
[2] Univ Turin, Regina Elena Hosp, I-10124 Turin, Italy
[3] Univ Pavia, IRCCS Policlin San Matteo, I-27100 Pavia, Italy
[4] Univ Bologna, St Orsola Hosp, I-40126 Bologna, Italy
[5] G Di Cristina ARNAS Hosp, Palermo, Italy
[6] Hosp Bergamo, Div Pediat, Bergamo, Italy
[7] Univ Florence, Meyer Hosp, I-50121 Florence, Italy
[8] San Gerardo Hosp, Pediat Clin, Monza, Italy
[9] Giannina Gaslini Inst, Div Pediat Infect Dis, Genoa, Italy