1. Department of Basic Medicine and Forensic Medicine; Baotou Medical College; Baotou Inner Mongolia China
2. Institute of Microbiology; Center for Disease Control and Prevention of Guangdong Province; Panyu District Guangzhou China
3. Department of Pathology; National Institute of Infectious Diseases; Musashi-murayama Tokyo Japan
4. Research Institute for Microbial Diseases; Osaka University; Suita Osaka Japan
5. Department of Virology II; National Institute of Infectious Diseases; Musashi-murayama Tokyo Japan