[1] Univ Bologna, Dept Specialized Expt & Diagnost Med, Microbiol Unit, Lab Virol,St Orsola Polyclin, Bologna, Italy
[2] Univ Ferrara, Dept Med Sci, Sect Infect Dis & Dermatol, Ferrara, Italy
[3] Univ Ferrara, Dept Med Sci, Sect Hematol & Rheumatol, Ferrara, Italy