1. Arthropod-Borne Animal Diseases Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Manhattan, Kansas.
2. Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado.
3. Department of Virology, Central Veterinary Institute of Wageningen University, Lelystad, the Netherlands.
4. Department of Biochemistry, Centre for Human Metabonomics, North-West University, Potchefstroom, South Africa.