1. These authors contributed equally to this work and share first authorship.
2. SC Microbiology and Virology, IRCCS Policlinico San Matteo, Pavia, Italy
3. Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, University of Pavia, Pavia, Italy
4. Department of Hygiene and Health Prevention, Health Protection Agency, Metropolitan Area of Milan, Milan, Italy
5. Virology Department, Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna, Brescia, Italy
6. Department of Hygiene and Health Prevention, Health Protection Agency Val Padana, Mantova, Italy
7. Postgraduate School in Public Health, Department Biomedical Sciences for Health, University of Milan, Milan, Italy
8. General Directorate of Welfare, Regione Lombardia, Milan, Italy
9. Health Director Staff, Health Protection Agency, Metropolitan Area of Milan, Milan, Italy
10. SC Chemical-Clinical Analysis and Microbiology Laboratory, ASST Lodi, Lodi, Italy
11. Department of Emergency and Urgency, ASST Lodi, Lodi, Italy
12. SC Infectious and Tropical Diseases, ASST Lodi, Lodi, Italy
13. These authors contributed equally to this work and share last authorship.