1. Department of Clinical Epidemiology, Hyogo Medical University , 1-1 Mukogawa, Nishinomiya 663-8501, Japan
2. Department of Infectious Diseases, Shimane Prefectural Central Hospital , 4-1-1 Himebara, Izumo 693-8555, Japan
3. Department of Pharmacy, Shimane Prefectural Central Hospital , 4-1-1 Himebara, Izumo 693-8555, Japan
4. Center for Health Surveillance and Preventive Medicine, Tokyo Medical University , 6-1-1 Shinjuku, Shinjuku 160-8402, Japan
5. Shimane Prefectural Central Hospital , 4-1-1 Himebara, Izumo 693-8555, Japan