1. National Centre for Epidemiology, Surveillance and Health Promotion, National Institute of Health (Istituto Superiore di Sanità, ISS), Rome, Italy
2. Ministry of Health, Department of Prevention and Communication, Rome, Italy
3. Department of Infectious, Parasitic and Immune-mediated Diseases, National Institute of Health (Istituto Superiore di Sanità, ISS), Rome, Italy
4. Regional Health Authority of Veneto, Italy
5. Regional Health Authority of Sardinia, Italy
6. Local Health Authority of Oristano, Sardinia, Italy
7. Regional Health Authority of Emilia-Romagna, Italy
8. Regional Health Authority of Lombardy, Italy
9. Regional Health Authority of Friuli-Venezia Giulia, Italy