1. Department of Infectious Diseases, Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan;
2. Emerging and Re-emerging Infectious Diseases, Graduate School of Medicine, Tohoku University, Sendai, Japan;
3. Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan;
4. Department of Infection Control, Graduate School of Medicine/Faculty of Medicine, Osaka University, Osaka, Japan