Hiroyuki Fujikura1, Natsuko Imakita2, Taku Ogawa3, Kei Kasahara2. 1. Center for Infectious Diseases, Nara Medical University Hospital, Nara, Japan. hiroyuki.fujikura@gmail.com. 2. Center for Infectious Diseases, Nara Medical University Hospital, Nara, Japan. 3. Infection Control Center, Osaka Medical and Pharmaceutical University Hospital, Osaka, Japan.