1 Department of Infectious Diseases, Disease Control and Prevention Centre, National Centre for Global Health and Medicine, Tokyo, Japan; Emerging and Re-emerging Infectious Diseases, Graduate School of Medicine, Tohoku University, Sendai, Japan. Electronic address: tesuzuki@hosp.ncgm.go.jp.
2 Department of Infectious Diseases, Disease Control and Prevention Centre, National Centre for Global Health and Medicine, Tokyo, Japan.
3 Department of Infectious Diseases, Disease Control and Prevention Centre, National Centre for Global Health and Medicine, Tokyo, Japan; Emerging and Re-emerging Infectious Diseases, Graduate School of Medicine, Tohoku University, Sendai, Japan.