1. Department of Medical Technology, Kyorin University School of Health Sciences, Hachioji-shi,1 and
2. Department of Veterinary Public Health, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu-shi, Hokkaido,2 and
3. Denka Seiken Co., Gosen-shi, Niigata,3Japan
4. Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Shinjuku-ku,4 Tokyo,