1. Department of Microbiology and Infectious Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia.
2. Department of Virology, Croatian National Institute of Public Health, Zagreb, Croatia and School of Medicine University of Zagreb, Zagreb, Croatia.
3. Croatian Veterinary Institute, Regional Veterinary Institute Split, Split, Croatia.
4. Communicable Disease Epidemiology Service, Croatian National Institute of Public Health, Zagreb, Croatia.
5. National Reference Centre for West Nile Disease, Istituto G. Caporale Teramo, Teramo, Italy.