1. Division of Clinical Microbiology, Department of Microbiology, Tokyo Metropolitan Institute of Public Health, 3–24–1, Hyakunincho, Shinjuku-ku, Tokyo 179–0073, Japan
2. Department of Infectious Diseases, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160–8582, Japan
3. Department of Infectious Diseases, Tokyo Medical University Ibaraki Medical Center, 3–20–1, Chuo, Ami-machi, Inashiki-gun, Ibaraki 300–0395, Japan
4. Department of Clinical Laboratories, Tokyo Medical University Ibaraki Medical Center, 3–20–1, Chuo, Ami-machi, Inashiki-gun, Ibaraki 300–0395, Japan
5. Travelers’ Medical Center, Tokyo Medical University Hospital, 6–7–1, Nishi-Shinjuku, Shinjuku-ku, Tokyo 160–0023, Japan