1. Laboratory of Clinical and Epidemiological Virology, Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
2. Instituto de Virología, CICVyA, INTA Castelar, Buenos Aires, Argentina
3. Veterinary Medical Research Institute, Hungarian Academy of Sciences, Budapest, Hungary
4. Ondersterpoort Veterinary Institute, Onderstepoort, South Africa
5. Dr György Radó Military Medical Centre, Budapest, Hungary
6. Department of Medical Genetics, University of Pécs, Pécs, Hungary
7. Irish Equine Centre, Johnstown, Naas, Co. Kildare, Ireland
8. Molecular Epidemiology Laboratory, Cork Institute of Technology, Cork, Ireland
9. Clinical Research and Development, Novartis Vaccines and Diagnostics, Inc., Cambridge, MA 02139, USA