1. Veterinary Epidemiology, Division of Health and Environmental Sciences, Department of Veterinary Medicine, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan.
2. National Veterinary Assay Laboratory, Kokubunji-shi, Japan.
3. Department of Applied Veterinary Science, The United Graduated School of Veterinary Science, Gifu University, Yanagido, Japan.
4. Food Hygiene, Division of Health and Environmental Sciences, Department of Veterinary Medicine, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan.