| Affiliation: | 1. Department of Production Animal Clinical Sciences, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences (NMBU), Ullevålsveien 72, Pb 8146 Dep, N-0033 Oslo, Norway;2. National Veterinary Institute, Section for Epidemiology, Ullevålsveien 68, Pb 750 Sentrum, N-0106 Oslo, Norway;3. Faculty of Agricultural Sciences, University of Aarhus, Blichers Alle 20, Pb 50, DK-8830 Tjele, Denmark;4. NMBU, Faculty of Veterinary Medicine and Biosciences, Department of Basic Sciences and Aquatic Medicine, Ullevålsveien 72, Pb 8146 Dep, N-0033 Oslo, Norway |
