[1] Ist Super Sanita, Dept Therapeut Res & Med Evaluat, Viale Regina Elena 299, I-00161 Rome, Italy
[2] Catholic Univ, Dept Infect Dis, Rome, Italy
[3] Catholic Univ, Dept Paediat, Rome, Italy
[4] Univ Milan, Dept Obstet & Gynaecol, DMSD San Paolo Hosp, Sch Med, Milan, Italy
[5] Univ Pavia, Dept Paediat, IRCCS Policlin San Matteo, Via Palestro 3, I-27100 Pavia, Italy
[6] Univ Turin, Dept Obstet & Neonatol, Citta Salute & Sci Hosp, Turin, Italy
[7] Univ Modena & Reggio Emilia, Infect Dis Clin, Dept Med Specialties, Modena, Italy
[8] INMI Lazzaro Spallanzani, Rome, Italy
[9] Luigi Sacco Hosp, Dept Paediat, Milan, Italy
[10] Univ Milan, Milan, Italy
[11] Azienda Osped Parma, Dept Infect Dis & Hepatol, Parma, Italy
[12] Univ Bari, Dept Obstet & Gynaecol, Bari, Italy
[13] Univ Bari, Policlin Hosp, Bari, Italy