1. Research Center for Food Safety; Graduate School of Agricultural and Life Sciences; The University of Tokyo; Tokyo Japan
2. Bacterial and Parasitic Diseases Research Division; National Institute of Animal Health; National Agriculture and Food Research Organization; Tsukuba Ibaraki Japan
3. The United Graduate School of Veterinary Sciences; Gifu University; Gifu Japan
4. Epidemiological Information Section; National Institute of Animal Health; National Agriculture and Food Research Organization; Tsukuba Ibaraki Japan