1. Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Greifswald, Isle of Riems, Germany.
2. Institute of Veterinary Pathology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany.
3. Paul-Ehrlich-Institute, Federal Institute for Vaccines and Biomedicines, Langen, Germany.