1. Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
2. Division of Animal Science & National Swine Resource and Research Center, College of Agriculture Food and Natural Resources, University of Missouri, Columbia, MO, USA
3. School of Veterinary Medicine and Biomedical Sciences, Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE, USA
4. Genus plc, DeForest, WI, USA