1. Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
2. Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
3. Milken Institute School of Public Health, George Washington University, Washington, DC, USA
4. National Veterinary Institute, Technical University of Denmark, Frederiksberg, Denmark
5. Bisgaard Consulting, Viby Sjælland, Denmark
6. Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA