[1] UNIV ROME LA SAPIENZA,CHAIR PATHOL ANAT 2,VIALE REGINA ELENA 324,I-00161 ROMA,ITALY
[2] UNIV ROME LA SAPIENZA,INST INFECT DIS,I-00161 ROME,ITALY
[3] IST SUPER SANITA,VIROL LAB,I-00161 ROME,ITALY
[4] UNIV ROME TOR VERBATA,DEPT EXPTL MED,ROME,ITALY