[1] IRCCS L Spallanzani, Dipartimento Epidemiol, Rome, Italy
[2] Osped L Sacco, Clin Malattie Infett, Milan, Italy
[3] Azienda Osped L Sacco, Milan, Italy
[4] Div Malattie Infett S Maria Nuova, Reggio Emilia, Italy
[5] IRCCS L Spallanzani, Div Malattie Infett, Rome, Italy
[6] Azienda Osped D Cotugno, Div Malattie Infett, Naples, Italy
[7] Osped S Maria Annunziata, Div Malattie Infett, Florence, Italy
[8] Policlin Umberto 1, Dipartimento Malattie Infett & Trop, Rome, Italy
[9] Osped A Pugliese Catanzaro, Div Malattie Infett, Catanzaro, Italy
[10] Osped Riuniti Bergamo, Div Malattie Infett, I-24100 Bergamo, Italy
[11] Ist Super Sanita, Ctr Operat AIDS, I-00161 Rome, Italy