[1] Valtellina & Valchiavenna Hosp, Transfus Med & Haematol Dept, Sondrio, Italy
[2] Natl Blood Ctr, Rome, Italy
[3] A Manzoni Hosp, Transfus Serv, Lecce, Italy
[4] San Michele Hosp, Transfus Serv, Cagliari, Italy
[5] G Salvini Hosp, Transfus Serv, Garbagnate Milanese, Italy
[6] Univ Milan, Dept Publ Hlth Microbiol Virol, Milan, Italy