1. Department of Laboratory Medicine; Hirosaki University Graduate School of Medicine; Hirosaki Japan
2. Infection Control Center; Hirosaki University Hospital; Hirosaki Japan
3. Department of Clinical Laboratory; Hirosaki University Hospital; Hirosaki Japan
4. The Regional Network for Infection Monitoring/Control System; Akita Japan
5. Aomori Infection Control Network; Aomori Japan
6. Department of General Internal Medicine and Clinical Laboratory Medicine; Akita University Graduate School of Medicine; Akita Japan