Mugen Ujiie1, Koji Nabae2, Tokuaki Shobayashi2. 1. Tuberculosis and Infectious Diseases Control Division, Health Service Bureau, Ministry of Health, Labour and Welfare, Tokyo 100-8916, Japan. Electronic address: ujiie-mugen@mhlw.go.jp. 2. Tuberculosis and Infectious Diseases Control Division, Health Service Bureau, Ministry of Health, Labour and Welfare, Tokyo 100-8916, Japan.