1. School and Graduate Institute of Medical Technology, College of Medicine,1
2. Division of Epidemiology, National Institute of Preventive Medicine,2 and
3. Division of Vector-Borne Infectious Diseases, Center for Disease Control,3 Department of Health, The Executive Yuan, and
4. Institute of Preventive Medicine, National Defense Medical Center,4 Taipei,
5. Department of Immunology, Tzu Chi College of Medicine and Humanities,Hualien,5 Taiwan, Republic of China
6. Institute of Epidemiology, College of Public Health,6National Taiwan University, and