1. Laboratory of Microbiology, School of Health Sciences, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan
2. Japan Agency for Medical Research and Development/Japan International Cooperation Agency, Science and Technology Research Partnership for Sustainable Development, Tokyo, Japan
3. Nursing for Home Care and Chronic Nursing, School of Health Sciences, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan
4. Osaka Prefectural Institute of Public Health, Higashinari-ku, Osaka, Japan