[1] Univ Milan, Sect Infect Dis & Immunopathol, Dept Clin Sci L Sacco, Milan, Italy
[2] Univ Milan, Unit Stat & Biometry, Milan, Italy
[3] Univ Siena, Dept Biotechnol, I-53100 Siena, Italy
[4] Osped Riuniti Bergamo, Dept Microbiol & Virol, Bergamo, Italy
[5] Careggi Hosp, Dept Infect Dis, Florence, Italy
[6] Osped Riuniti Bergamo, Dept Infect Dis, Bergamo, Italy
[7] Ist Sci San Raffaele, Dept Virol, I-20132 Milan, Italy
[8] Fdn IRCCS Policlin San Matteo, Mol Virol Unit, Pavia, Italy
[9] Ist Sci San Raffaele, Dept Infect Dis, I-20132 Milan, Italy
[10] Univ Perugia, Infect Dis Clin, I-06100 Perugia, Italy
[11] A Manzoni Hosp, Infect Dis Clin, Lecce, Italy
[12] Fdn IRCCS Policlin San Matteo, Dept Infect Dis, Pavia, Italy
[13] Misericordia Hosp, Dept Infect Dis, Grosseto, Italy