1. Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan.
2. The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.
3. Fukushima Wildlife Rehabilitation Center, Nagakubo, Tamai, Ohtama Village, Fukushima, Japan.
4. School of Veterinary Medicine, Kitasato University, Aomori, Japan.