1. Animal Health Research Institute, Danshui, Taipei 25158, Taiwan
2. Graduate Institute of Veterinary Medicine, College of Bioresource and Agriculture, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 106, Taiwan
3. Research Center for Emerging Viral Infections, Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Kwei-Shan, Taoyuan 333, Taiwan