1Department of Health Sciences, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo City, Yamanashi, Japan, E-mail: HiroshiY@gmail.com
2Infection Control and Education Center, Nagasaki University, 7-1 Sakamoto-1, Nagasakishi, Japan, E-mail: HiroshiY@gmail.com
3Department of Health Promotion National Institute of Public Health, 2-3-6 Minami, Wako, Saitama, Japan, E-mail: HiroshiY@gmail.com
4Department of Clinical Medicine (Biostatistics), School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, Japan, E-mail: HiroshiY@gmail.com
5Infectious Disease Surveillance Center, National Institute of Infectious Diseases, 1-23-1 Toyama Shinjuku-ku, Tokyo, Japan, E-mail: HiroshiY@gmail.com