1. Unit of Medical Statistics and Molecular Epidemiology; University Campus Bio-Medico of Rome; Rome Italy
2. Unit of Virology; University Campus Bio-Medico of Rome; Rome Italy
3. Unit of Clinical Laboratory Science; University Campus Bio-Medico of Rome; Rome Italy
4. Internal Medicine Department; University Campus Bio-Medico of Rome; Rome Italy
5. Dipartimento di Igiene degli Alimenti; Istituto Zooprofilattico Sperimentale della Sardegna; Sassari Italy
6. Department of Biomedical and Clinical Sciences L. Sacco; University of Milan; Milan Italy
7. Department of Mental Health and Public Medicine; Section of Infectious Diseases, University of Campania Luigi Vanvitelli; Naples Italy