1. Research Center for Tropical Infectious Diseases, Nagasaki University Institute of Tropical Medicine, Nagasaki, Japan.
2. Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
3. School of Public Health, Fujian Medical University, Fuzhou, Fujian Province, China.
4. Department of Epidemiology, Peking Union Medical College, Beijing, China.