1. Department of Virology, Faculty of Medicine, PO Box 21, University of Helsinki, 00014 Helsinki, Finland
2. Research and Laboratory Department, Veterinary Virology, Finnish Food Safety Authority Evira, Mustialankatu 3, 00790 Helsinki, Finland
3. Research and Laboratory Department, Production Animal and Wildlife Health Research Unit, Finnish Food Safety Authority Evira, Elektroniikkatie 3, 90590 Oulu, Finland
4. Department of Virology and Immunology, Helsinki University Central Hospital Laboratory, HUSLAB, Haartmaninkatu 3, 00029 HUS, Helsinki, Finland
5. Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, University of Helsinki, PO Box 66, 00014 Helsinki, Finland