1. Department of Infectious, Parasitic and Immuno-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
2. Ricerca Fauna, Rome, Italy.
3. Present address: Institute for Environmental Protection and Research (ISPRA), Via Cà Fornacetta 9, 400064 Ozzano dell'Emilia, Italy.
4. National Centre for Epidemiology, Surveillance and Health Promotion, Istituto Superiore di Sanità, Rome, Italy.
5. Centro di Recupero per la Fauna Selvatica–LIPU, Rome, Italy.