[1] Univ Hosp Citta Salute & Sci Torino, Microbiol & Virol Unit, Virol Lab, I-10126 Turin, Italy
[2] Univ Turin, Dept Publ Hlth & Pediat, I-10126 Turin, Italy
[3] Univ Hosp Citta Salute & Sci Torino, Div Pneumol, I-10126 Turin, Italy
[4] Univ Turin, Univ Hosp Citta Salute & Sci Torino, Cardiac Surg Div, Dept Surg Sci, I-10126 Turin, Italy