1. Department of Biomedicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
2. Center of Biomedical Research, Research Center for Human Disease Modeling, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
3. Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
4. Avian Influenza Research Center, Kyoto Sangyo University, Kyoto 603-8555, Japan
5. Institute of Tropical Medicine, Nagasaki University, Nagasaki 851-2125, Japan
6. Laboratory of Experimental Animal Science and Medicine, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
7. Department of Virology, National Institute of Hygiene and Epidemiology, No. 1 Yersin Street, Hanoi, Vietnam