1. Division for Infection Control and Environmental Health, Department of Virology; Norwegian Institute of Public Health; Oslo Norway
2. Faculty of Veterinary Medicine, Department of Production Animal Clinical Sciences; Norwegian University of Life Sciences; Oslo Norway
3. Department of Production Animal Clinical Sciences, Section of Small Ruminant Research and Herd Health; Norwegian University of Life Sciences; Sandnes Norway
4. Norwegian Veterinary Institute; Oslo Norway
5. Division for Infection Control and Environmental Health, Department of Pest Control; Norwegian Institute of Public Health; Oslo Norway
6. Center for Virology; Medical University of Vienna; Vienna Austria