Affiliation: | (1) Inspection for Health Protection, PO Box 9012, 7200 GN Zutphen, The Netherlands, NL;(2) Institute of Infectious Diseases and Immunology, Utrecht University, PO Box 80.165, 3508 TD Utrecht, The Netherlands, NL;(3) Department of the Science of Food of Animal Origin, Faculty of Veterinary Medicine, Utrecht University, PO Box 80.165, 3508 TD Utrecht, The Netherlands, NL |