1. Centre for Tropical Diseases, Sacro Cuore Hospital, Negrar (Verona), Italy
2. Department of Prevention, ULSS 20, Verona, Italy
3. Direction of Prevention, Veneto region, Venice, Italy
4. Unit of Infectious Diseases, Rovigo Hospital, Italy
5. Department of Prevention, ULSS 18 Rovigo, Italy
6. Unit of Microbiology and Virology, Padua Hospital, Italy
7. Department of Public Health, Local Health Unit, Ravenna, Italy