[1] Univ Siena, Dept Med Biotechnol, Siena, Italy
[2] Univ Florence, Dept Expt & Clin Med, Florence, Italy
[3] Univ Turin, Dept Publ Hlth & Pediat Sci, AOU, City Hlth & Sci, Turin, Italy
[4] Univ Florence, Dept Surg & Translat Med, Florence, Italy
[5] Florence Careggi Univ Hosp, Clin Microbiol & Virol Unit, Florence, Italy
[6] Don Carlo Gnocchi Fdn, Florence, Italy